ArticleLiterature Review

Infant skin physiology and development during the first years of life: A review of recent findings based on in vivo studies

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Abstract

Infant skin is often presented as the cosmetic ideal for adults. However, compared to adult skin it seems to be more prone to develop certain pathological conditions, such as atopic dermatitis and irritant contact dermatitis. Therefore, understanding the physiology of healthy infant skin as a point of reference is of interest both from the cosmetic as well as from the clinical point of view. Clinical research on healthy infants is, however, limited because of ethical considerations of using invasive methods and therefore until recently data has been scarce. Technical innovations and the availability of non-invasive in vivo techniques, such as evaporimetry, electrical impedance measurement, in vivo video and confocal microscopy, and in vivo fibre-optic based spectroscopy, opened up the field of in vivo infant skin physiology research. Studies incorporating such methods have demonstrated that compared to adult, infant skin continues to develop during the first years of life. Specifically, infant skin appears to have thinner epidermis and stratum corneum (SC) as well as smaller corneocytes at least until the second year of life. The water-handling properties are not fully developed before the end of the first year and infant SC contains more water and less amounts of natural moisturizing factors. Such findings re-evaluate the old notions that skin is fully matured at birth. Armed with this knowledge, we are in a position not only to better understand infant dermatological conditions but also to design better skin care products respecting the distinct qualities of infant skin.

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... 5,6 Pela menor concentração de sebo presente na pele das crianças até o início da adolescência, não é necessário que os produtos de limpeza infantis tenham ação detergente potente. 7 A frequência do banho varia em cada país e é influenciada por fatores individuais, culturais e sociais, 8 porém os diferentes regimes adotados para sua realização podem determinar a manutenção ou alteração da barreira cutânea. O banho deve ser com água morna e de curta duração, a fim de minimizar a perda transepidérmica de água. ...
... O banho deve ser com água morna e de curta duração, a fim de minimizar a perda transepidérmica de água. 7,9 Os requisitos para a classificação do produto como infantil são: ser à base d'água, ser de baixa fixação e não apresentar toxicidade oral. 10 É de crucial importância o uso de produtos de higiene e cosméticos infantis, uma vez que a pele da criança se assemelha à do adulto como barreira eficaz a partir dos três e quatro anos de vida e, em produção sebácea, a partir dos dez a 12 anos. ...
... Banhos prolongados ocasionam maior perda transepidérmica de água. 7 Portanto, 52,1% das crianças estudadas podem ter as características da barreira cutânea prejudicadas por permanecer maior tempo no banho. O banho com temperatura adequada (37,0-37,5°C) preserva a estabilidade térmica e não aumenta a perda transepidérmica de água, 7 o que foi observado em 80,4% da população estudada. ...
Article
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Objective: To evaluate the hygiene practices and frequency of use of personal hygiene products, cosmetics, and sunscreen among children and adolescents. Methods: Cross-sectional study with interviews about skincare conducted with caregivers through closed-ended questions. We included patients up to 14 years of age waiting for consultation in pediatric outpatient clinics of a tertiary hospital. We performed a descriptive statistical analysis and applied the Kruskal-Wallis test and Fisher’s exact test to compare the practices according to maternal schooling. Results: We conducted 276 interviews. The median age of the participants was age four, and 150 (54.3%) were males. A total of 143 (51.8%) participants bathed once a day and 128 (46.3%) bathed two or more times a day, lasting up to ten minutes in 132 (47.8%) cases. Adult soap was used by 103 (37.3%) children and bar soap by 220 (79.7%). Fifty-three (19.2%) participants used sunscreen daily. Perfume was used by 182 (65.9%) children, hair gel by 98 (35.5%), nail polish by 62 (22.4%), and some type of make-up by 71 (25.7%) - eyeshadow by 30 (10.8%), lipstick by 52 (18.8%), face powder and mascara by 13 (4.7%). Make-up use started at a median age of 4 years. Henna tattoo was done in eight children. Conclusions: The children studied used unsuitable products for their skin, such as those intended for adults, used sunscreen inadequately, and started wearing make-up early, evidencing the need for medical orientation.
... Многие исследователи считают, что к моменту рождения кожа и эпидермальный барьер у доношенного новорожденного (гестационный возраст от 37 до 41 нед) сформированы практически полностью и могут компетентно выполнять свои функции, но это суждение спорно [8][9][10]. Несмотря на то, что с гистологической точки зрения созревание кожи новорожденного по большей части завершено, ее физико-химические свойства сформированы пока еще не до конца и полноценную защитную и другие функции на начальных этапах постнатального периода кожа обеспечить не может [11,12]. ...
... G. Stamatas и соавт., изучая микроскопическую структуру поверхности кожи младенца и взрослого, получили сравнительные данные о микрорельефе кожи: оказалось, что у младенцев сеть линий микрорельефа более плотная, так называемые островки корнеоцитов по размеру меньше, а гидратация рогового слоя выше по сравнению со взрослыми (старше 18 лет) [11]. Толщина слоев эпидермиса и количество клеток в них тоже отличаются: так, у младенцев в возрасте от 6 до 24 мес толщина рогового слоя тоньше примерно на 30%, а эпидермиса -на 20% по сравнению со взрослыми [16]. ...
... У недоношенных новорожденных созревание эпидермального барьера напрямую зависит от гестационного возраста и в среднем достигается через 2-4 нед постнатальной жизни (при гестационном возрасте > 25 нед) [11,37]. Толщина рогового слоя и ТЭПВ у недоношенных детей также зависят от гестационного возраста: при сроке гестации до 26 нед роговой слой еще не сформирован, а значение ТЭПВ достигает максимальных значений -~75 г/м 2 в час, которое постепенно уменьшается за счет созревания рогового слоя и эпидермального барьера (рис. ...
Article
Full-text available
The article presents modern data on the features of the structure of the skin and the formation of the epidermal barrier in premature and young children. Information is given regarding changes in the properties of the skin: microrelief, hydration, transepidermal water loss, acidity, content of the natural moisturizing factor, and sebum secretion. Attention is also paid to the role of vernix caseosa in the formation of a mature epidermal barrier and data on the use of emollients are provided.
... The skin of healthy infants is inherently physiologically fragile compared to adults with a lower resistance to aggressions [5]. The maturation process of the skin from birth through the first year of life has been studied extensively using noninvasive biophysical measurement methods concentrated on the stratum corneum and the physical development of skin barrier function [5][6][7][8]. It is generally believed that the skin barrier is competent in full-term infants at birth, based on measurements of transepidermal water loss (TEWL) [5,9]; however, the waterhandling properties of the stratum corneum do not appear to be fully developed until at least the end of the first year [5,7]. ...
... The maturation process of the skin from birth through the first year of life has been studied extensively using noninvasive biophysical measurement methods concentrated on the stratum corneum and the physical development of skin barrier function [5][6][7][8]. It is generally believed that the skin barrier is competent in full-term infants at birth, based on measurements of transepidermal water loss (TEWL) [5,9]; however, the waterhandling properties of the stratum corneum do not appear to be fully developed until at least the end of the first year [5,7]. Indeed, recent evidence based on the waterholding and transport properties of the stratum corneum suggest that skin barrier maturation continues into the fourth year of life [8,10]. ...
... This development appears to be dependent on the anatomical site, with TEWL and conductance measurements taken in the less environmentally exposed inner upper arm being higher and taking longer to decrease to adult values than in the more exposed dorsal forearm [8]. Capacitance, an indirect parameter of skin hydration state, increases steeply in the first days or weeks after birth, reflecting increasing skin hydration [6,7]. Skin surface pH is higher in neonates and decreases steeply in the first few days after birth, and more gradually thereafter [6,11]. ...
Article
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Background: Little is known about the impact of nutrition on the development of skin structure and function in infants. Methods: We investigated epidermal, dermal, and subcutis parameters of aged-matched well-nourished and moderately undernourished infants in this single-center, cross-sectional, noninterventional study using noninvasive methods (skin caliper, 20-MHz sonography, transepidermal water loss, skin pH, and corneometry). Plasma fatty acids were determined as an indicator of nutritional differences. 310 infants from different age groups, i.e., 1 week, 4 weeks, and 6, 9, 12, 24, and 36 months were included. Approximately half of each age group was well-nourished (WHO reference values weight-for-height/length Zscore: -0.75 ≤ Z ≤ 0.75) and the other half was moderately undernourished (-3 ≤ Z < -2). Results: Structural maturational differences in the deeper dermis and subcutis regions of the skin and subtle functional changes in the epidermis were observed in moderately undernourished infants without notable clinical symptoms. Reduced skin barrier function or skin hydration were not observed in the undernourished infants, and skin pH shifted to more acidic values in this group. Conclusion: These findings reveal a greater impact of moderate undernutrition on the development of the dermis and subcutis and suggest that critical epidermal functions such as skin barrier and pH are mostly maintained.
... After birth, skin continues evolving notably in its physiological functions. Adaptations and maturation processes are described: variation in transepidermal water loss (TEWL) which reflect the setting-up of skin barrier function [12,[24][25][26][27], changes in skin hydration and water-holding capacities [12,[26][27][28], skin pH variation [24,27,28], sweat and sebaceous glands functioning [15,24,29], development of the skin innate immunity role through proteins, lipids and immunity cells and microbiome [12,13]. ...
... After birth, skin continues evolving notably in its physiological functions. Adaptations and maturation processes are described: variation in transepidermal water loss (TEWL) which reflect the setting-up of skin barrier function [12,[24][25][26][27], changes in skin hydration and water-holding capacities [12,[26][27][28], skin pH variation [24,27,28], sweat and sebaceous glands functioning [15,24,29], development of the skin innate immunity role through proteins, lipids and immunity cells and microbiome [12,13]. ...
... After birth, skin continues evolving notably in its physiological functions. Adaptations and maturation processes are described: variation in transepidermal water loss (TEWL) which reflect the setting-up of skin barrier function [12,[24][25][26][27], changes in skin hydration and water-holding capacities [12,[26][27][28], skin pH variation [24,27,28], sweat and sebaceous glands functioning [15,24,29], development of the skin innate immunity role through proteins, lipids and immunity cells and microbiome [12,13]. ...
Article
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In infants, pruritus is frequently considered as absent because they do not scratch themselves. Because pruritus could induce severe adverse effects in this vulnerable population, we aimed to review existing evidence on the ability of young infants to experience itch and on how to assess itch-related discomfort in this population. A literature review was performed (Pubmed, Google Scholar). Neurological itch pathways are well described. Skin development starts early during gestation. At 34 weeks of gestation, skin is almost complete while skin adaptations occur after birth. Newborn skin is neurologically functional, including the ability for young infants to feel pain. Similarities and interactions between pain and pruritus support the hypothesis that infants could feel pruritus. However, the existence of pruritus in infants has never been evidenced. Many itchy conditions can affect them, suggesting non-negligible prevalence of infant pruritus among which atopic dermatitis (AD) is the most studied disease. Studies reported a negative impact of AD on children and their families. There is no existing validated method to assess pruritus in infants, although they may feel pruritus and chronic pruritus can lead to serious adverse effects. To appropriately diagnose pruritus appears of great interest among young infants. Development of a method is required to this aim.
... Therefore, we set out in Table 1 the nomenclature to clarify the age groups of children that are the focus of this review. Although the skin barrier function of neonates and infants has been reviewed [1], it is important to note that the skin physiology and function in preterm infants is less developed compared with full-term infants [2][3][4][5][6][7]. A number of studies have also confirmed a high incidence of percutaneous toxicity from topical substances in preterm infants [3,[8][9][10][11]. ...
... From an anatomical point of view, the differences between infant skin and adult skin are limited. The most distinctive characteristics of infant skin are a thinner SC, thinner epidermal layer, and smaller corneocytes [2]. In terms of skin physiology, infants have Table 1. ...
... The skin development process starts during early gestation-in the first trimester [2]. Structural and functional maturation continues until the full-term, and the SC is fully formed at 34-weeks of gestational age [2]. ...
Article
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A good understanding of infant skin should provide a rationale for optimum management of the health of this integument. In this review, we discuss the skin barrier function of infants, particularly with reference to the use of diapers and baby wipes. The skin barrier of newborns continues to develop with age. Two years after birth, the barrier properties of infant skin closely resemble those of adult skin. However, several risk factors may contribute to impaired skin barrier and altered skin permeability in infants. Problems may arise from the use of diapers and baby wipes. The skin covered by a diaper is effectively an occluded environment, and thus is vulnerable to over-hydration. To date there has been no published information regarding dermal absorption of ingredients contained in baby wipes. Similarly, dermal absorption of topical ingredients in infants with underlying skin conditions has not been widely explored. Clearly, there are serious ethical concerns related to conducting skin permeation studies on infant skin. However, the increasing availability of non-invasive methods for in vivo studies is encouraging and offers new directions for studying this important patient group.
... The thickness of the newborn's skin is about 40-60% of adult skin [3]. It takes 8 to 10 weeks after birth for the stratum corneum to reach full maturity, during which the skin is unprotected, so it is more exposed to possible nosocomial infections [4]. The hydration state of the skin in newborns is low, and during the next 2-4 weeks, it increases significantly due to the onset of sweat glands. ...
... After birth, the pH of the skin constantly decreases and after about 4 days it reaches pH = 5, where the acid barrier is created, which is ideal for skin flora and provides adequate protection. It is worth noting, however, that this is not true for the entire skin surface: For example, the closed and moisture-exposed diaper area may have a considerably higher pH [4]. ...
Article
Full-text available
Semisolid dosage forms are recommended for the dermal care of babies and children. If we look at the ingredients of these preparations, there are still many cases in which there are substances (occlusive agents, preservatives) that no longer meet certain requirements of the modern age, so it is timely to replace them with other substances. The aim of this work was to formulate a science-based formulation with new components that keep or improve its moisturizing properties, rheological parameters, and microbiological stability. Occlusive oils, like white petrolatum and liquid paraffin and the preservative parabens are traditional ingredients in oil in water creams, were replaced with white beeswax, sunflower oil, and phenoxyethanol, respectively. Cocoa butter, urea, and glycerol were added to improve long-lasting hydration and support the barrier function of the reformulated creams. The rheological properties of the formulations were determined. The effects of the preparations on skin hydration and on the barrier function of the skin were tested. Furthermore, microbiological stability was investigated. The result of the reformulation was an o/w cream that provided a good longer-lasting hydration effect; supported the barrier function of the baby skin without occlusion; and had adequate consistency, easy spreading, a pleasant skin feeling, proper pH, and good microbiological stability.
... Their stratum corneum layer is thinner than that of term infants (Gullino et al., 2017). Additionally, the skin structure of newborns is drier than adults and the capacity of holding water is less (Stamatas et al., 2011). This negatively affects the skin's ability to offer protection against microorganisms (Arredondo & Tamayo, 2007; Garcia Bartels et al., 2014;Visscher et al., 2009;Wilson, 2011). ...
... This negatively affects the skin's ability to offer protection against microorganisms (Arredondo & Tamayo, 2007; Garcia Bartels et al., 2014;Visscher et al., 2009;Wilson, 2011). The development of the skin's barrier function continues throughout the first year of life (Fluhr et al., 2012;Nikolovski et al., 2008;Stamatas et al., 2011). Skin quality changes dramatically with gestational age. ...
Article
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Aims The study aims to examine the effect of delaying first bathing on skin barrier function, body temperature, and neonatal comfort of late preterm infants. Design This study is a multi‐centre, single‐blind, prospective randomized controlled trial. Methods We attempt to report this randomized controlled trial to comply with the SPIRIT. The study population will consist of 80 late preterm infants born at three centres (hospitals) in Turkey. The study, between September 2020–September 2021 will be held in the Neonatal Intensive Care Unit. The participants will be randomly divided into two groups, each with different bathing times. The first group (N = 40) will be bathed between 24–48 hr after birth and the second group (N = 40) will be bathed between 48–72 hr after birth. Each group's intervention will be performed by a blinded researcher. The infants’ transepidermal water loss, body temperature, and comfort level will be measured before the bath and again at three times after the bath. The measurements will be taken by a blinded researcher and blinded nurse. Discussion The benefits of infant bathing are known. However, the effect of delaying first bathing of late preterm infants on skin barrier function is unknown. At the same time, the effect of delaying bathing on maintaining body temperature and neonatal comfort is unknown. Impact This study is expected to provide a piece of credible evidence of the delay of first bathing and benefit of neonatal care in this population. It is thought that postponing bathing time of late preterm infants to 48–72 hr after birth will lead to a protective effect on skin barrier and temperature. It will be performed in clinical practice if it can effectively improve transepidermal water loss and heat loss. Trial registration It was registered at ClinicalTrials.gov in January 2020 (NCT04231799).
... Fourteen studies demonstrated assessment or preventive-themed designs and are presented in Table 1. 5,[16][17][18][19][20][21][22][23][24][25][26][27][28] Several factors identified within the 14 studies are associated with the development of DD to include stool frequency, antibiotic usage, diarrhea, and oral thrush. 5,8,16,21,23 Researchers identified vaginal or cesarean section delivery as a clinical characteristic in 2 studies. ...
... Physiologic measures (eg, evaporimeter, pH, and skin hydration) for skin condition were used in 9 of the studies in Table 1 to assist in the assessment of skin condition, DD development, and quantify changes in DD skin condition. 8,16,[20][21][22]24,25,27,28 Changes in skin condition were determined by the use of a visual assessment tool often paired with physiologic tools. Strength in the full description of skin condition may lie in the interpretation of physiologic measurements, but may be elevated when combined with visual assessment. ...
Article
Background: Diaper dermatitis (DD) severity is demonstrated by the degree of erythema and skin breakdown. Many studies describe diaper dermatitis, but lack a full description of clinical characteristic (CC) involvement. Purpose: The purpose of this literature review is to explore the descriptions of CC of infants with DD provided within infant DD literature. Search strategy: PubMed and Web of Science were searched using the keywords: diaper dermatitis, diaper rash, infant, and neonate. The inclusion criteria for this project are as follows: published after 1990, English language, include skin assessment or evaluation, and infant/children < two years of age. Review and opinion articles were excluded. Results: A total of 454 studies were retrieved, 27 remained after review for duplicates and relevance. The CC described most often were: type of feeds, stool frequency, history of DD, use of antibiotics, and delivery mode. Synthesis of evidence: The studies reported inconsistent CC and a lack of correlation between these characteristics and the condition of diapered skin. Many studies focused solely on the efficacy of interventions lacking description of possible relationships between DD and CC. Implications for practice: Skin condition outcome variables can be improved with the acknowledgment of the impact CC have on the development of DD. The combination of assessment measures and CC may ultimately demonstrate more merit or rigor for describing DD severity and skin condition. Implications for research: Future research should expand this exploration to include environmental or contributing factors to continue to identify additional risk factors for DD.
... Other studies on emollient use during infancy reported a similar absence of an effect of the intervention on TEWL 15,23 . TEWL measurements are influenced by environmental factors and more crucially for infants, subject-specific parameters including stress and crying 25 . This may have affected our ability to detect differences between the groups. ...
Article
Full-text available
Background: Protecting the skin barrier in early infancy may prevent atopic dermatitis (AD). We investigated if daily emollient use from birth to 2 months reduced AD incidence in high risk infants at 12 months. Methods: This was a single-center, two-armed, investigator-blinded, randomized controlled clinical trial (NCT03871998). Term infants identified as high risk for AD (parental history of AD, asthma or allergic rhinitis) were recruited within 4 days of birth and randomised 1:1 to either twice-daily emollient application for the first 8 weeks of life (intervention group), using an emollient specifically formulated for very dry, AD-prone skin, or to standard routine skin care (control group). The primary outcome was cumulative AD incidence at 12 months. AD <6 months was diagnosed based on clinical presence of AD. The UK Working Party Diagnostic Criteria were applied when diagnosing AD between 6 and 12 months. Results: 321 infants were randomised (161 intervention and 160 control), with 61 withdrawals (41 intervention, 20 control). The cumulative incidence of AD at 12 months was 32.8% in the intervention group vs. 46.4% in the control group, p = 0.036 [Relative risk (95%CI): 0.707 (0.516, 0.965)]. One infant in the intervention group was withdrawn from the study following development of a rash that had a potential relationship with the emollient. There was no significant difference in the incidence of skin infections between the intervention and control groups during the intervention period (5.0% vs. 5.7%, P>0.05). Conclusions: This study has demonstrated that early initiation of daily specialized emollient use until 2 months reduces the incidence of AD in the first year of life in high-risk infants.
... A barreira da pele da criança é mais vulnerável do que no adulto, pela permeabilidade aumentada, maior probabilidade de secar e mais propensa à penetração de substâncias (Figura 3). A pele imatura além de ser 30% mais fina que a do adulto(20), desidrata cinco vezes mais rápido que a pele do adulto(21).O envelhecimento da pele diminui a taxa de cicatrização de feridas, pois a pele das pessoas mais velhas é mais propensa a danos face à sua vulnerabilidade. A idade poderá influenciar todos as fases do processo cicatricial, pois com a idade, a velocidade metabólica está alterada.FIGURA2. ...
Technical Report
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A pele é o maior órgão do corpo humano e desempenha funções absolutamente vitais para a homeostasia da pessoa. O seu compromisso não só compromete as funções fisiológicas, mas também tem um impacto, real ou potencial, nas vivências da pessoa na sua vertente psicossocial. Um exemplo paradigmático é o caso da cicatriz, esta poderá ter um impacto funcional na pessoa (exemplo: limitação da amplitude do movimento numa zona articular), ou impacto na autoimagem e com consequente alteração da vivência individual psicossocial. No decorrer deste documento, iremos refletir num conjunto de condições da pele a que todo o profissional de saúde deverá estar atento no processo de avaliação de risco de lesão. O foco deverá ser sempre a prevenção da lesão e maximizar a resistência da pele aos agentes agressores externos.
... The reason for the higher cutaneous involvement in children ADRs may be ascribed to the peculiar physiology of this age, in fact, neonates and infants have a partially mature and not fully epidermis (Rashed et al., 2012). Thus, the skin is more permeable and vulnerable to chemical and microbial aggressions (Stamatas et al., 2011). ...
Article
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Children represent one of the most susceptible groups to adverse drug reactions (ADRs), as a consequence of physiological growth and maturation of different organ systems. The aim of this study was to characterize the frequency, preventability and seriousness of ADRs recorded in the Pediatric Emergency Department (ED) of the University hospital of Messina, in Sicily. All the suspected adverse reactions to drugs and vaccines collected from 2012 to 2018 were selected and then analyzed. Only adverse drug reactions (ADRs) with a probable or possible causality assessment were included, according to the Naranjo Algorithm and the World Health Organization criteria; the preventability assessment using Schumock and Thornton criteria was also carried out. The Medical Dictionary for Regulatory Activities (MedDRA) was used to group ADRs. Of 75,935 admissions to the Pediatric ED, 120 were due to suspected ADRs. The rate of hospital admission due to ADRs (75.8%) was significantly greater than that of patients without ADRs (11.9%). Among pediatric patients with ADRs the median (Q1–Q3) age was 29.5 (12–73.25) months. Most of ADRs were observed in infants and children (43.3% and 41.7%, respectively vs adolescents, 15%). In addition, in children with ADRs, females [41 (14–105)] were older than males [23 (11–45)] (p=0.044). Most adverse reactions were serious (75.8%) and 20.8% were preventable or probably preventable; however, the majority of serious ADRs (93.4%) resulted without sequelae. The reactions were found to be as probable (54.2%) or possible (45.8%). Vaccines (n=63), antibacterials (n=31) and anti-inflammatory medicines (n=14) were the most frequently drugs involved. Organ toxicity mapping due to vaccines was general disorders and administration site conditions (65.1%), nervous disorders (50.2%), cutaneous disorders (35%), followed by gastrointestinal disorders (20.6%). Cutaneous disorders (76%) gastrointestinal (20.7%), general (15.5%), and nervous disorders (8.6%) were the organ toxicity mapping due to drugs. Active pharmacovigilance has an essential role in supporting the development of strategies aimed at intervention to reduce admissions due to ADRs. Our data suggest that ADRs represent the first cause of hospitalization to the Pediatric Emergency Department. Furthermore, according to the literature, vaccines and antibiotics are the most frequent cause of adverse drug reactions in children.
... More recently, optical methods, such as optical coherence tomography (OCT) [10,11,12,13,14,15,16,17], confocal microscopy (CM) [18,19,20,21,22,23,24,25,26,27], and multiphoton microscopy (MPM) were introduced [28,29,30,31,32]. Due to their spatial resolution to the scale of a micrometre, and despite their limited depth of view to a maximum of 200 µm in depth, fantastic details of the anatomy of the outermost part of the skin can be obtained in vivo. ...
Chapter
Among cross‐sectional skin imaging methods, magnetic resonance (MR) imaging plays a particular role for many reasons, including submillimeter spatial resolution, contrast based on molecular interactions, and high versatility of MR quantitative information through multiple intrinsic skin parameter measurements. However, despite its relative complexity and limited access for clinical applications, MR imaging is still considered as a very powerful tool for furthering knowledge of the physiology of healthy and diseased skin. After describing MR requirements for acquiring high spatial resolution images of the skin, the chapter will first present an overview of in vivo published works in the MR research community with a particular emphasis on imaging of the face. Then the main results of MR applications on in vitro or ex vivo skin samples will be presented, with a focus on research on water states in reconstructed skin samples, which offer new information for better decoding the contribution of water states in the epidermis and dermis to transepidermal water loss and more generally to barrier function quality. At the end, after a short summary, some perspectives toward functional MR imaging of the skin will be highlighted.
... The skin barrier has a protective role against the external world and in maintaining homeostasis. After leaving the womb, the skin of newborns undergoes active and physiological adaptation to the new environment and a transition to maturation within the rst months of life 1,2 . Infant skin functions are vulnerable to extrauterine triggers such as bathing and moisture, which implies skin incompetence 3,4 that is different from adults [5][6][7] . ...
Preprint
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Background Skin barrier functions develop after birth and may be related to skin disorders in infants. Objectives We aimed to assess associations between dynamic trends of four skin barrier functional parameters in early life with infant atopic dermatitis (AD).Methods Based on the prospective cohort MKNFOAD (NCT02889081), we examined transepidermal water loss (TEWL), stratum corneum hydration (SCH), skin pH, and sebum content at five anatomical sites (cheek, forehead, forearm, abdomen, and lower leg) in 418 term infants at birth, 42 days, and 6 months. Trend differences by sex and association with AD at age 1 year were tested using variance analyses. Associations of the parameters with AD risk were tested using discrete time survival analysis, adjusting extensive covariates including parental history of allergy, infant’s sex, birth weight (kg), and delivery mode. Odds ratios (ORs) and 95% confidence interval (CIs) were reported.ResultsOverall TEWL and SCH appeared trends of increase while skin surface pH and sebum content showed trends of decrease within the first 6 postnatal months. Sex differences were significant for sebum content only ( p <0.001). After adjustment for parental and children covariates, cheek TEWL (OR=1.26, 95% CI 1.00–1.57, p =0.045) at birth and 42 days (OR=1.52, 95% CI 1.17–1.97, p =0.002) were significantly associated with increased AD risk. Associations were not observed between SCH, skin pH, and sebum content at birth or 42 days with AD. Conclusions Skin barrier functions of Chinese term infants varied nonlinearly after birth. Higher postnatal TEWL levels in early life indicate higher risk of early-onset AD.
... Historically, infant skin beyond the first few weeks following birth has been regarded as structurally and functionally equivalent to adult. Experimental data over the last two decades have challenged this dogma and have revealed that skin undergoes a maturation process that can last for several years after birth (Stamatas et al., 2011;Chiou and Blume-Peytavi, 2004;Visscher et al., 2017). This process involves higher keratinocyte proliferation and desquamation rates compared to adult (Stamatas et al., 2010;Liu et al., 2018). ...
Article
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Computational models of skin permeability are typically based on assumptions of fixed geometry and homogeneity of the whole epidermis or of epidermal strata and are often limited to adult skin. Infant skin differs quantitatively from adult in its structure and its functional properties, including its barrier function to permeation. To address this problem, we developed a self-organizing multicellular epidermis model of barrier formation with realistic cell morphology. By modulating parameters relating to cell turnover reflecting those in adult or infant epidermis, we were able to generate accordingly two distinct models. Emerging properties of these models reflect the corresponding experimentally measured values of epidermal and Stratum Corneum thickness. Diffusion of an externally applied substance (e.g. caffeine) was simulated by molecular exchange between the model “agents”, defined by the individual cells and their surrounding extracellular space. By adjusting the surface concentration and the intercellular exchange rate, the model can recapitulate experimental permeability data, following topical exposure. By applying these parameters to an infant model, we were able to predict the caffeine concentration profile in infant skin, closely matching experimental results. This work paves the way for better understanding of skin physiology and function during the first years of life.
... В оценке влияния климата на развитие АтД необходимо также учитывать и возрастные анатомо-физиологические особенности кожи. Так, например, исследования барьерной функции эпидермиса показывают, что поверхностная концентрация липидов и естественного увлажняющего фактора в коже младенцев снижены по сравнению с таковыми у взрослых [55,56]. Также у детей зафиксированы высокий уровень pH, повышенная десквамация эпидермиса, увеличенная скорость пролиферации эпидермоцитов и трансэпидермальной потери воды [57]. ...
Article
Atopic dermatitis (AD) is chronic recurrent inflammatory skin disease with a high prevalence and significant negative effect on patients' quality of life. AD pathogenesis is based on the complex interactions between genetic factors, immune mechanisms, state of the skin barrier and environmental effects. The climate itself is the complex of many components, such as: temperature, humidity, precipitation, wind and season. All of them play fundamental role in the natural ecosystem and human health establishment. The climate is changing rapidly, and these changes are progressing faster than ever in the last thousand years. This review shows how climate and environmental changes can affect the course of AD. The data on utilization efficiency of emollient plus for moderating of climatic conditions adverse effects on epidermal structures at patients with AD is presented.
... As for SIH, topical medication could achieve local drug distribution and reduce the release of the drug into the blood circulation, so its topical use is safe. Two factors are related to the valid penetration of timolol maleate: the immature skin barrier function of Test for overall effect: Z = 3.02 (p = 0.002) Test for subgroup differences: χ 2 = 0.07, df = 1 (p = 0.80); I 2 = 0% an infant under the age of 1 year and the lipophilic property of timolol maleate, which improves skin penetration [28]. As for topical timolol, heterogeneous preparations including 0.5% timolol eyedrop, 0.5% timolol solution and timolol 0.5% gel, have been ap-plied for the treatment of SIH [7,9,11]. ...
Article
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Background: To evaluate the efficacy and safety of topical β-blockers in the treatment of superficial infantile hemangiomas (SIH) and mixed infantile hemangiomas (MIH), respectively, and compare the efficacy and safety of topical β-blockers with other interventions. Methods: The PRISMA guidelines were adhered to. We searched for randomized controlled trials in databases from 2010 to 2018 comparing topical β-blockers with other interventions for infantile hemangiomas. The outcomes evaluated were efficacy and adverse effects. Data analyses were performed using RevMan 5.3. Publication bias was assessed to account for bias in patient selection. Results: Eleven studies, involving 1,235 patients, were subjected to this meta-analysis. Six studies compared topical β-blockers with other interventions (propranolol, placebo, corticosteroids or pulsed dye laser) in treating SIH, and 5 studies evaluated the efficacy and safety of a topical β-blocker when it was combined with another intervention in treating MIH. A topical β-blocker was discovered to be as effective as oral propranolol in treating SIH (risk ratio, RR, 0.96, 95% confidence interval, CI, 0.91-1.02, p = 0.20, I2 = 0%), and topical β-blockers were more beneficial than placebo, corticosteroids or pulsed dye laser in treating SIH (RR 2.25, 95% CI 1.66-3.05, p < 0.00001, I2 = 0%). Topical β-blockers combined with another intervention gave rise to a better clinical response in the treatment of MIH than intervention alone (RR 1.99, 95% CI 1.10-3.60, p = 0.02, I2 = 55%) (standard mean difference 0.80, 95% CI 0.28-1.31, p = 0.002, I2 = 0%). Compared with oral propranolol, topical β-blockers were associated with fewer incidences of adverse effects (RR 0.05, 95% CI 0.01-0.39, p = 0.004, I2 = 0%). No significant difference in adverse effects was found when a topical β-blocker was combined with another intervention in treating MIH (RR 1.01, 95% CI 0.58-1.74, p = 0.98, I2 = 0%). Conclusions: This meta-analysis provided evidence that topical β-blockers may replace oral propranolol as first-line therapy for SIH and that they are of additive value in treating MIH.
... В оценке влияния климата на развитие АтД необходимо также учитывать и возрастные анатомо-физиологические особенности кожи. Так, например, исследования барьерной функции эпидермиса показывают, что поверхностная концентрация липидов и естественного увлажняющего фактора в коже младенцев снижены по сравнению с таковыми у взрослых [55,56]. Также у детей зафиксированы высокий уровень pH, повышенная десквамация эпидермиса, увеличенная скорость пролиферации эпидермоцитов и трансэпидермальной потери воды [57]. ...
Article
Atopic dermatitis (AD) is chronic recurrent inflammatory skin disease with a high prevalence and significant negative effect on patients' quality of life. AD pathogenesis is based on the complex interactions between genetic factors, immune mechanisms, state of the skin barrier and environmental effects. The climate itself is the complex of many components, such as: temperature, humidity, precipitation, wind and season. All of them play fundamental role in the natural ecosystem and human health establishment. The climate is changing rapidly, and these changes are progressing faster than ever in the last thousand years. This review shows how climate and environmental changes can affect the course of AD. The data on utilization efficiency of emollient plus for moderating of climatic conditions adverse effects on epidermal structures at patients with AD is presented.
... Longitudinal research that follows infants through childhood and young adulthood will help tease apart the relative contribution of various host behaviors and ecological processes for skin microbial community establishment and maintenance. For example, characterizing changes to skin pH and moisture during infancy [90,135,136] and puberty [137] will help distinguish "normal" ecological changes from major disruptions, such as the use of antibiotics, that can lead to negative health outcomes. If exposure to commensal microbes in early life is critical for proper immune system development [138], and the skin microbiome plays a role in regulating immune responses and inflammation [5], then differential microbial exposures during infancy may be linked to the onset of health disparities later in life. ...
Article
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Metacommunity theory dictates that a microbial community is supported both by local ecological processes and the dispersal of microbes between neighboring communities. Studies that apply this perspective to human-associated microbial communities are thus far limited to the gut microbiome. Yet, the skin serves as the primary barrier between the body and the external environment, suggesting frequent opportunities for microbial dispersal to the variable microbial communities that are housed across skin sites. This paper applies metacommunity theory to understand the dispersal of microbes to the skin from the physical and social environment, as well as between different skin sites on an individual’s body. This includes highlighting the role of human behavior in driving microbial dispersal, as well as shaping physiological properties of skin that underscore local microbial community dynamics. By leveraging data from research on the skin microbiomes of amphibians and other animals, this paper provides recommendations for future research on the skin microbial metacommunity, including generating testable predictions about the ecological underpinnings of the skin microbiome.
... The reason for increased cutaneous involvement of ADRs in paedriatric patients can be attributed to this age group's unique physiology; in fact, they have a partially matured epidermis that is not fully developed (Rashed et al., 2012;Rosli et al., 2017). As a result, the skin becomes more porous and vulnerable to chemical and microbial attacks (Stamatas et al., 2011). ...
Article
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Drug safety in paediatric patients is a serious public health concern around the world. The paediatric patients are more prone to adverse drug reactions (ADRs) than adults. Moreover, there is a scarcity of information about ADRs in paediatric patients. This study was conducted to determine the frequency, causality, severity, preventability of paediatric patients’ ADRs reported in a tertiary care hospital in Adana, Turkey. A retrospective study was conducted on all spontaneously reported ADRs between January 01, 2020, to July 30, 2021, in paediatric patients. The ADRs reports were evaluated in terms of gender, age, ADR characteristics, suspected drugs and reporting source. All included ADRs reports were characterized according to the Naranjo Algorithm/World Health Organization (WHO) causality scales, Hartwig/Siegel and Common Terminology Criteria for Adverse Events (CTCAE) severity scales, the modified Schoumock and Thornton preventability scale and hospital pharmacovigilance center criteria for seriousness. Therapeutic groups were also coded using the WHO-Anatomical Therapeutic and Chemical (ATC) classification. During the study period, 8,912 paediatric patients who were admitted had 16 ADRs with 1.7 ADRs/1,000 admissions. The majority of ADRs were found in infants (31.2%) and children (56.2%) as compared to adolescents (12.5%). ADRs were observed more in females (81.2%) than males. Skin (62.5%) was the most affected organ due to the ADRs, and maculopapular rash and erythema multiforme were the most commonly reported symptoms. Most ADRs were probable/likely (93.7%), severe (50%), preventable or probably preventable (43.7%) and serious (37.5%). Antibiotics (93.7%) were found to be the most common cause of ADRs in paediatric patients. The majority of ADRs were associated with vancomycin (68.7%). Most of the ADRs were reported by a medical doctor in this study. This small sample size study highlights significant problems of ADRs in paediatric patients, mainly caused by antibiotics and with a majority of ADRs manifest as skin reactions. Furthermore, a high proportion of the identified ADRs were found to be preventable. More focused efforts are needed at the national level to avoid preventable ADRs in hospitals. Monitoring and management of ADRs and future studies would be beneficial for better patient care and safety.
... However, our current understanding of how the composition and function of skin immune cells evolves during infancy and childhood relies heavily on murine studies. Direct extrapolation from mice to humans is fundamentally flawed given the presence of species-specific cell types [90,91] and profound differences in timing of thymic [92][93][94][95], skin barrier [96,97], and hair follicle [98,99] development. However, two general principles derived from mice appear to be applicable to humans. ...
Article
Early life is a dynamic period for skin microbial colonization and immune development. We postulate that microbial exposures in this period durably alter the skin immune trajectory and later disease susceptibility. Bacteria contribute to infant skin immune imprinting via interactions with microbes as well as with cutaneous epithelial and immune cells. Excellent research is underway at the skin microbiome–immune interface, both in deciphering basic mechanisms and implementing their therapeutic applications. As emphasized herein, focusing on the unique opportunities and challenges presented by microbial immune modulation in early life will be important. In our view, only through dedicated study of skin–microbe crosstalk in this developmental window can we elucidate the molecular underpinnings of pivotal events that contribute to sustained host–microbe symbiosis.
... Other differences are also evident, e.g. the epidermis and the S. corneum are thinner, the corneocytes are smaller, the content of natural moisturizing factor (NMF) is lower, and the skin is more prone to pH imbalances in part possibly due to the fact that the microbiome of a baby's skin is different to that of adults. Furthermore, sebaceous and sweat glands are less developed and regulated, and the melanin content is lower [1,2,3,4]. All these characteristics give baby skin less protection against moisture loss, cold and hot temperatures, but also against environmental aggressors such as pathogens, irritants and UV radiation. ...
Article
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https://www.sofw.com/de/hikashop-menu-for-categories-listing/product/980-gentle-care-for-delicate-skin When babies set out to explore the world around them, they do not yet have the protection adults count on. Baby skin is thinner and more sensitive, calling for tailored care to defend it from moisture loss, sun and environmental aggressors. Anja Stork, Annette Mehling and Petra Schulte explain how BASF’s baby care concept delivers essential and safe care.
... Babies also experience higher water loss through the skin, cell renewal is twice as fast, and baby skin contains less natural moisturizing factors. 1 The epidermis is morphologically composed of distinct and stratified layers reflecting the differentiation of keratinocytes that migrate from the basal layer to the superficial layer. ...
Article
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Even though its development starts early in utero, neonatal skin is still immature at birth relative to adult and undergoes a maturation process extending to the first years of life. It is now established that the stratum corneum is thinner and dryer, and that skin contains less natural moisturizing factors and lipids in newborns compared to children and adults. Moreover, it has been shown that skin surface area expansion is not linear throughout life and is peaking perinatally, suggesting that baby skin has a higher epidermal cellular turnover. Despite growing resources showing differences between adult and infant skin physiology, molecular and metabolic specificities of baby skin are still poorly understood. To address this critical knowledge gap, we performed an integrative transcriptomic and metabolomic study comparing human primary foreskin and abdominal keratinocytes from male babies and female adults, respectively. Based on state-of-the-art integrative frameworks, our analyses revealed a major shift in the global energetic metabolism in baby foreskin keratinocytes compared to adult abdominal keratinocytes, highlighting increased amino acid metabolism and mitochondrial oxidative phosphorylation in baby cells to fuel the citric acid cycle, while showing glycolysis as the major cell energy source in adult cells.
... As the first step to locate the eye area, a sagittal image slice with the longest anterior-posterior distance was selected from the sagittal image slices. In that sagittal slice, we placed a vertical line at a 15 mm distance from the front-most vertical line (Fig. 3a), considering the thickness of the skull and the average diameter of the infant's eyes [30][31][32] . By taking the coronal slice that contained the vertical line, the coronal slice with the eyeballs could be selected, where the projection in the left-right direction showed a peak near the eye position (Fig. 3b), because the eyes were represented as high intensities. ...
Article
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It is challenging to extract the brain region from T2-weighted magnetic resonance infant brain images because conventional brain segmentation algorithms are generally optimized for adult brain images, which have different spatial resolution, dynamic changes of imaging intensity, brain size and shape from infant brain images. In this study, we propose a brain extraction algorithm for infant T2-weighted images. The proposed method utilizes histogram partitioning to separate brain regions from the background image. Then, fuzzy c-means thresholding is performed to obtain a rough brain mask for each image slice, followed by refinement steps. For slices that contain eye regions, an additional eye removal algorithm is proposed to eliminate eyes from the brain mask. By using the proposed method, accurate masks for infant T2-weighted brain images can be generated. For validation, we applied the proposed algorithm and conventional methods to T2 infant images (0–24 months of age) acquired with 2D and 3D sequences at 3T MRI. The Dice coefficients and Precision scores, which were calculated as quantitative measures, showed the highest values for the proposed method as follows: For images acquired with a 2D imaging sequence, the average Dice coefficients were 0.9650 ± 0.006 for the proposed method, 0.9262 ± 0.006 for iBEAT, and 0.9490 ± 0.006 for BET. For the data acquired with a 3D imaging sequence, the average Dice coefficient was 0.9746 ± 0.008 for the proposed method, 0.9448 ± 0.004 for iBEAT, and 0.9622 ± 0.01 for BET. The average Precision was 0.9638 ± 0.009 and 0.9565 ± 0.016 for the proposed method, 0.8981 ± 0.01 and 0.8968 ± 0.008 for iBEAT, and 0.9346 ± 0.014 and 0.9282 ± 0.019 for BET for images acquired with 2D and 3D imaging sequences, respectively, demonstrating that the proposed method could be efficiently used for brain extraction in T2-weighted infant images.
... However, infants have smaller corneocytes and thinner stratum corneum which lasts until 2 years of age. When compared with adults, skin of newborns contains fewer fibrils and decreased dermal collagen, thereby making it more prone to skin diseases [2]. In India, skin diseases are becoming increasingly important due to many factors such as varied climate, genetic, age, overcrowding, nutrition habits, poor hygiene, and pollution [3]. ...
Preprint
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Objective: The objective of the study was to study the prevalence of various skin diseases in pediatric population. Methods: A prospective observational study was conducted at private children's outpatient clinic in Warangal from March to August 2018 with the prior approval from the Institutional Ethical Committee BIPS/IEC/2018/P8. A total of 200 patients with various skin diseases of age group <17 years were included in the study. Results: Out of 200 pediatric skin disorders, male children 138 (69%) outnumbered female children 62 (31%). The mean age of the study population was found to be 5.85±4.11 years. About 64% of the patients are from rural area and 36% are from urban. The percentage of skin disorders is allergic infections (26%), bacterial infections (23%), viral infections (11%), fungal infections (7.5%), parasitic infections (6%), autoimmune disorders (4%), and skin adnexa (2.5%). Conclusion: Our study concludes that the prevalence of allergic and bacterial skin infections was found to be common among male children from rural area.
... However, in vivo studies using confocal laser scanning microscopy in the last 20 years have shown that differences in skin anatomy and physiology do exist as a function of age following birth, which was not previously well-captured in light microscopy and chemically fixed skin samples in infants. Physiological and structural skin features that differ between infants and adults, which were identified from the analysis of non-invasive in vivo measurements, have been previously reviewed [22]. These variations in pediatric skin anatomy and physiology with respect to adults can induce differences in the dermal absorption of a given chemical between the two populations. ...
Article
Full-text available
The higher skin surface area to body weight ratio in children and the prematurity of skin in neonates may lead to higher chemical exposure as compared to adults. The objectives of this study were: (i) to provide a comprehensive review of the age-dependent anatomical and physiological changes in pediatric skin, and (ii) to construct and evaluate an age-dependent pediatric dermal absorption model. A comprehensive review was conducted to gather data quantifying the differences in the anatomy and physiology of child and adult skin. Maturation functions were developed for model parameters that were found to be age-dependent. A pediatric dermal absorption model was constructed by updating a MoBi implementation of the Dancik et al. 2013 skin permeation model with these maturation functions. Using a workflow for adult-to-child model extrapolation, the predictive performance of the model was evaluated by comparing its predicted rates of flux of diamorphine, phenobarbital and buprenorphine against experimental observations using neonatal skin. For diamorphine and phenobarbital, the model provided reasonable predictions. The ratios of predicted:observed flux in neonates for diamorphine ranged from 0.55 to 1.40. For phenobarbital, the ratios ranged from 0.93 to 1.26. For buprenorphine, the model showed acceptable predictive performance. Overall, the physiologically based pediatric dermal absorption model demonstrated satisfactory prediction accuracy. The prediction of dermal absorption in neonates using a model-based approach will be useful for both drug development and human health risk assessment.
... 78 Skin maturation and adaptation to the post-partum environment happens over an extended period of time, during which desquamation slowly increases. 79 Compared with older adults, neonates, infants and children show a visible 'turnover' and increased production of keratin in hair, skin and nails. Several observations suggest that infant mechanisms of di erentiation and desquamation are underdeveloped or poorly regulated compared with adults. ...
... 78 Skin maturation and adaptation to the post-partum environment happens over an extended period of time, during which desquamation slowly increases. 79 Compared with older adults, neonates, infants and children show a visible 'turnover' and increased production of keratin in hair, skin and nails. Several observations suggest that infant mechanisms of di erentiation and desquamation are underdeveloped or poorly regulated compared with adults. ...
... 129 Skin maturation and adaptation to the post-partum environment happens over an extended period of time, during which desquamation slowly increases. 130 Compared with older adults, neonates, infants and children show a visible 'turnover' and increased ...
Article
p>Although great strides have been made to tackle hospital-acquired pressure ulcers (HAPUs), there is a need for greater recognition of device-related pressure ulcers (DRPUs), including their causes, management and prevention. This consensus statement, an updated second edition, aims to continue raising awareness of these largely preventable injuries and, crucially, to stimulate action. DRPUs are relatively common and account for a growing proportion of HAPUs. Updated information on the incidence of DRPUs is described in chapter 1. Although it is recognised that DRPUs increase the financial burden of healthcare, there is little formal analysis of their economic impact. This needs to be addressed; robust evidence on the burden of DRPUs and the value that can be released by adopting prevention strategies is needed to help drive action. Our understanding of the pathophysiology of DRPUs has improved significantly over the past few years; this is described in chapter 2. One crucial difference between PUs and DRPUs is that body-weight forces are less significant in DRPUs, with the force being exerted from a device that is typically strapped or taped onto the body. Devices and their securement may generate high stress concentrations in tissues, leading to cell and tissue-damage pathways associated with sustained deformation. As more evidence is published on DRPUs, recurring themes are emerging, as outlined in chapter 3: The most vulnerable patients are bearing the brunt of DRPUs; paediatric and neonatal patients, and all those needing critical care are particularly susceptible. During the COVID-19 pandemic, a new high-risk population (people with severe COVID-19 infection) emerged. They are at increased risk of DRPUs because of their need for prolonged ventilatory support, especially when 'proning' Devices associated with DRPUs are often used to perform essential, life-saving functions. They include continuous positive airway pressure (CPAP) masks or endotracheal tubes. Minimising their use is clearly not an option, so practice innovation is needed Although the most common locations for DRPUs are the face, ears, lower legs and heels, any location where a device comes into close contact with the skin can be at risk. In the same vein, any device, whether needed for a medical purpose or not, has the capacity to cause injury if its use is not properly managed. Vigilance is needed for all patients. What can be done? The importance of routine risk assessment is covered in chapter 4. Although use of a validated risk assessment tool is the vital first step, this will not be enough on its own. Several steps can be taken to ensure the safe use of devices. These are described in chapter 5 and include device repositioning, cushioning with prophylactic dressings and moisture control (only where possible and clinically appropriate). Of key importance is the development of an institutional protocol and champions to ensure all necessary steps are adopted. For any of these changes to be put into practice, awareness of DRPUs needs to increase. A number of proposals are outlined in chapter 6. A change of focus among health professionals and policy makers, along with more investment in education and training, are needed. All patients being managed with a medical device must be considered as at high risk. The pandemic introduced the world to the problem of DRPUs in health professionals caused by the extended wear of personal protective equipment. Health professionals also have a right to expect institutional protocols and provision of devices that protect them from DRPUs. Cutting-edge ideas and technologies that may be available in the future are described in chapter 7. When designing new products, manufacturers of medical devices have a duty of care to investigate the risks of DRPUs associated with their products and mitigate them, wherever possible. Our developing understanding of how the design, structure and materials used in medical devices contribute to DRPUs will help us develop new solutions for tomorrow. The first step is for everyone involved to ask themselves, 'what can I do to help?' There is work to be done-your journey to reduce DRPUs starts here!.</p
... Until recently, human skin was considered to be structurally and functionally mature at birth. It is now known that skin continues to mature in humans for at least one year after birth [91]. The basal barrier function of skin is already active in newborn humans and rodents, but it is less robust and resilient than in the older juvenile or adult [92]. ...
Article
This review focuses on preweaning ontogenic and developmental processes that can influence the selection of the appropriate age at which to start dosing rodent pups in juvenile animal studies (JAS). The ICH S11 guideline on 'Nonclinical Safety Testing in Support of Development of Paediatric Medicines' highlights the need to adapt the age from which animals are dosed according to the stage of development in the target organs/tissues of concern in the youngest pediatric patients. Rodents (rat or mouse) are the most common species for JAS. Despite previous practices, based on comparative ontogeny, it is rarely necessary to dose rodents younger than one week of age since postnatal day (PND)7 is appropriate to address concern for the vast majority of organs. In exceptional cases, earlier dosing (e.g., PND4) can be appropriate to address specific concern in preterm neonates and when a tissue of concern has a particularly early developmental trajectory in the rodent compared to humans. The comparative development of the CNS is particularly complex. While exposure of rodents from PND10 covers most CNS development stages relevant to human neonates, a later dosing start (yet, not later than PND14) can sometimes be appropriate to reflect specific aspects (e.g., transformation of GABAergic transmission). An extended study design including subsets of several ages can be helpful to address multiple concerns within a preweaning JAS. Such design can allow for individual assessment of each concern, whilst minimizing (potentially irrelevant) signals from tissues exposed at a developmental stage that do not match the human situation.
... Skin function and structure change throughout our lifetime, 25,26 whether this refers to skin maturation during childhood or to skin aging during adulthood. RCM allows us to visualize such changes by imaging the skin of different age groups. ...
Article
Significance: Reflectance confocal microscopy (RCM) is a noninvasive, in vivo technology that offers near histopathological resolution at the cellular level. It is useful in the study of phenomena for which obtaining a biopsy is impractical or would cause unnecessary tissue damage and trauma to the patient. Aim: This review covers the use of RCM in the study of skin and the use of machine learning to automate information extraction. It has two goals: (1) an overview of information provided by RCM on skin structure and how it changes over time in response to stimuli and in disease and (2) an overview of machine learning approaches developed to automate the extraction of key morphological features from RCM images. Approach: A PubMed search was conducted with additional literature obtained from references lists. Results: The application of RCM as an in vivo tool in dermatological research and the biologically relevant information derived from it are presented. Algorithms for image classification to epidermal layers, delineation of the dermal-epidermal junction, classification of skin lesions, and demarcation of individual cells within an image, all important factors in the makeup of the skin barrier, were reviewed. Application of image analysis methods in RCM is hindered by low image quality due to noise and/or poor contrast. Use of supervised machine learning is limited by time-consuming manual labeling of RCM images. Conclusions: RCM has great potential in the study of skin structures. The use of artificial intelligence could enable an easier, more reproducible, precise, and rigorous study of RCM images for the understanding of skin structures, skin barrier, and skin inflammation and lesions. Although several attempts have been made, further work is still needed to provide a definite gold standard and overcome issues related to image quality, limited labeled datasets, and lack of phenotype variability in available databases.
Article
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Objective: The purpose of the present study was to investigate effective masking levels (EMLs) for bone conduction (BC) auditory brainstem response (ABR) testing in infants and adults. Early hearing detection and intervention programs aim to limit delays in identifying ear-specific type/degree of hearing loss in infants using the ABR. Ear-specific assessment poses challenges as sound delivered to one ear can travel across the skull and activate the contralateral cochlea. Wave V amplitude and latency measures ipsilateral and contralateral to the bone oscillator can be compared to isolate the test cochlea in some cases; however, when these findings are equivocal, clinical masking is required. This study aims to determine EMLs for ABRs elicited to 500- and 2000-Hz BC stimuli for normal-hearing infants (0 to 18 months) and adults. Design: Participants were 21 adults (18 to 54 years) and 24 infants (5 to 47 weeks) with normal hearing. BC 500- and 2000-Hz brief tonal stimuli at intensities approximating normal levels were presented via a B-71 oscillator (infants: 20 dB nHL at 500 Hz and 30 dB nHL at 2000 Hz; adults: 500 and 2000 Hz at 20 and 30 dB nHL, respectively). White noise masking was presented binaurally via ER-3A earphones (22 to 82 dB SPL; 10-dB steps). The lowest level of masking to eliminate a BC response was deemed the EML. Results: For stimuli presented at 20 dB nHL, adult mean (1 SD) EMLs for 500 and 2000 Hz were 65 (9) and 53 (6) dB SPL, respectively. Mean EMLs for infants were 80 (6) dB SPL for 500 Hz at 20 dB nHL and 64 (9) dB SPL for 2000 Hz at 30 dB nHL. Compared to adults, infants required approximately 13 dB more masking at 500 Hz but a similar amount of masking at 2000 Hz. Infants required 26 dB more masking at 500 versus 2000 Hz, whereas, adults required only 12 dB more masking. Conclusions: Maximum binaural EMLs for infant BC responses elicited to 500 Hz at 20 dB nHL are 82 dB SPL, and for 2000 Hz at 30 and 40 dB nHL, respectively, are 72 and 82 dB SPL. Monaural masking levels for the nontest ear (assuming 10 dB of interaural attenuation) recommended clinically are as follows: (1) 500 Hz: 72 and 82 dB SPL at 20 and 30 dB nHL, respectively; and (2) 2000 Hz: 62, 72, and 82 dB SPL at 30, 40, and 50 dB nHL, respectively. Unsafe levels of white noise would be needed to effectively mask at greater stimulus levels.
Thesis
The number of people suffering from skin cancer has increased in recent years and is likely to increase in the future. Therefore, skin cancer prevention and sun protection is a current issue. Children spend a lot of time outdoors and are particularly susceptible to UV damage, which is why they should be specially protected. Most of their time is spent in kindergarten. Therefore, in the Erlking Sun Study 2015 we recorded the attitude to the sun and the knowledge about skin and the sunprotection of the kindergarten in 79 kindergartens in Upper Franconia with a structured questionnaire. The study is the first of its kind in Upper Franconia and shows the need for action regarding sunprotection and skin cancer prevention in kindergartens. Although most nurseries emphasize the use of hats and sunscreen, few pay attention to children wearing long-sleeved sunprotection clothes and sunglasses. This should be a goal in future sunscreen campaigns, as well as avoidance of intense sun exposure around noon and staying in the shade. With regard to the shading of both the open space and the outdoor play areas, there is still a clear need for improvement. The UV Index should also be included in this context. A mention of the index in weather reports and quick accessibility on the Internet or in weather apps could be improved. Sunscreen campaigns should be aimed at children, parents and caregivers, and should not only educate about the required sunscreen, but also point out the role model function of adults. The most skin cancer risk factors were recognized in our study with the exception of intermittent, intense UV-exposure, such as during a holiday in the south. Sunprotection campaigns should pay attention to this. In addition, they should try to change the attitude for tanned skin. As shown in our study, knowledge does not always mean good sunprotection behavior. Tanned skin is still considered healthy and attractive, which can be a reason for the missing success of such campaigns.
Article
Objective:Newborns require special care because their skin is much more sensitive and thinner than adults. From the products to be selected to the umbilical cord care; prevention of the pus; Parents and health professionals should pay attention to some important points in so many issues ranging from bathing conditions. In this study, it is aimed to systematically examine the studies about skin care of newborns. Materials and Methods:A total of 2792 studies published between 2012 and 2019 were examined. A total of nine publications were included in the study and evaluated in terms of comparison, limitations and results. Results:From the few studies with comparable data, there was no evidence that there was no significant difference between the tested washing products and the water or the tested baby wipes and water. There was some evidence to suggest daily use of emollients in a full-body bath. However, the use of olive oil or sunflower oil for the baby's dry skin may adversely affect the skin barrier. There was no evidence of hair/scalp care or baby massage. Conclusion:Although there is evidence of significant randomized controlled trials comparing the use of certain products to water or another product alone for bathing, cleaning and diaper care, the strength of this evidence is low due to the inconsistency of the outcome measures in terms of treatment area or time. It is recommended to increase the number of randomized controlled trials with the appropriate methodology for skin care of newborns.
Article
Background: Eczema and food allergy are common health conditions that usually begin in early childhood and often occur in the same people. They can be associated with an impaired skin barrier in early infancy. It is unclear whether trying to prevent or reverse an impaired skin barrier soon after birth is effective for preventing eczema or food allergy. Objectives: Primary objective To assess the effects of skin care interventions such as emollients for primary prevention of eczema and food allergy in infants. Secondary objective To identify features of study populations such as age, hereditary risk, and adherence to interventions that are associated with the greatest treatment benefit or harm for both eczema and food allergy. Search methods: We performed an updated search of the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, and Embase in September 2021. We searched two trials registers in July 2021. We checked the reference lists of included studies and relevant systematic reviews, and scanned conference proceedings to identify further references to relevant randomised controlled trials (RCTs). SELECTION CRITERIA: We included RCTs of skin care interventions that could potentially enhance skin barrier function, reduce dryness, or reduce subclinical inflammation in healthy term (> 37 weeks) infants (≤ 12 months) without pre-existing eczema, food allergy, or other skin condition. Eligible comparisons were standard care in the locality or no treatment. Types of skin care interventions could include moisturisers/emollients; bathing products; advice regarding reducing soap exposure and bathing frequency; and use of water softeners. No minimum follow-up was required. Data collection and analysis: This is a prospective individual participant data (IPD) meta-analysis. We used standard Cochrane methodological procedures, and primary analyses used the IPD dataset. Primary outcomes were cumulative incidence of eczema and cumulative incidence of immunoglobulin (Ig)E-mediated food allergy by one to three years, both measured at the closest available time point to two years. Secondary outcomes included adverse events during the intervention period; eczema severity (clinician-assessed); parent report of eczema severity; time to onset of eczema; parent report of immediate food allergy; and allergic sensitisation to food or inhalant allergen. Main results: We identified 33 RCTs comprising 25,827 participants. Of these, 17 studies randomising 5823 participants reported information on one or more outcomes specified in this review. We included 11 studies, randomising 5217 participants, in one or more meta-analyses (range 2 to 9 studies per individual meta-analysis), with 10 of these studies providing IPD; the remaining 6 studies were included in the narrative results only. Most studies were conducted at children's hospitals. Twenty-five studies, including all those contributing data to meta-analyses, randomised newborns up to age three weeks to receive a skin care intervention or standard infant skin care. Eight of the 11 studies contributing to meta-analyses recruited infants at high risk of developing eczema or food allergy, although the definition of high risk varied between studies. Durations of intervention and follow-up ranged from 24 hours to three years. All interventions were compared against no skin care intervention or local standard care. Of the 17 studies that reported information on our prespecified outcomes, 13 assessed emollients. We assessed most of the evidence in the review as low certainty and had some concerns about risk of bias. A rating of some concerns was most often due to lack of blinding of outcome assessors or significant missing data, which could have impacted outcome measurement but was judged unlikely to have done so. We assessed the evidence for the primary food allergy outcome as high risk of bias due to the inclusion of only one trial, where findings varied based on different assumptions about missing data. Skin care interventions during infancy probably do not change the risk of eczema by one to three years of age (risk ratio (RR) 1.03, 95% confidence interval (CI) 0.81 to 1.31; risk difference 5 more cases per 1000 infants, 95% CI 28 less to 47 more; moderate-certainty evidence; 3075 participants, 7 trials) or time to onset of eczema (hazard ratio 0.86, 95% CI 0.65 to 1.14; moderate-certainty evidence; 3349 participants, 9 trials). Skin care interventions during infancy may increase the risk of IgE-mediated food allergy by one to three years of age (RR 2.53, 95% CI 0.99 to 6.49; low-certainty evidence; 976 participants, 1 trial) but may not change risk of allergic sensitisation to a food allergen by age one to three years (RR 1.05, 95% CI 0.64 to 1.71; low-certainty evidence; 1794 participants, 3 trials). Skin care interventions during infancy may slightly increase risk of parent report of immediate reaction to a common food allergen at two years (RR 1.27, 95% CI 1.00 to 1.61; low-certainty evidence; 1171 participants, 1 trial); however, this was only seen for cow's milk, and may be unreliable due to over-reporting of milk allergy in infants. Skin care interventions during infancy probably increase risk of skin infection over the intervention period (RR 1.33, 95% CI 1.01 to 1.75; risk difference 17 more cases per 1000 infants, 95% CI one more to 38 more; moderate-certainty evidence; 2728 participants, 6 trials) and may increase the risk of infant slippage over the intervention period (RR 1.42, 95% CI 0.67 to 2.99; low-certainty evidence; 2538 participants, 4 trials) and stinging/allergic reactions to moisturisers (RR 2.24, 95% 0.67 to 7.43; low-certainty evidence; 343 participants, 4 trials), although CIs for slippages and stinging/allergic reactions were wide and include the possibility of no effect or reduced risk. Preplanned subgroup analyses showed that the effects of interventions were not influenced by age, duration of intervention, hereditary risk, filaggrin (FLG) mutation, chromosome 11 intergenic variant rs2212434, or classification of intervention type for risk of developing eczema. We could not evaluate these effects on risk of food allergy. Evidence was insufficient to show whether adherence to interventions influenced the relationship between skin care interventions and eczema or food allergy development. Authors' conclusions: Based on low- to moderate-certainty evidence, skin care interventions such as emollients during the first year of life in healthy infants are probably not effective for preventing eczema; may increase risk of food allergy; and probably increase risk of skin infection. Further study is needed to understand whether different approaches to infant skin care might prevent eczema or food allergy.
Article
Infancy is probably the most dynamic period of life characterized by a rapid, concordant and well‐coordinated development of all tissues and systems in our body. These include the cutaneous tissue and the immune system, both of which undergo a maturation process during the first years of life. The composition of skin microbiome, the ensemble of microflora living on the skin surface and in its appendages are highly dependent on both the skin and immune system maturation processes. It is not surprising then that the skin microbiome undergoes its own maturation process before it becomes relatively stable over time for an individual. In this chapter we will review recent findings from studies advancing our knowledge on the skin and immune system maturation processes, as well as the infant skin microbiome dynamics and the role of microbial bi‐directional transmission between the mother and the infant.
Article
Background: Eczema and food allergy are common health conditions that usually begin in early childhood and often occur together in the same people. They can be associated with an impaired skin barrier in early infancy. It is unclear whether trying to prevent or reverse an impaired skin barrier soon after birth is effective in preventing eczema or food allergy. Objectives: Primary objective To assess effects of skin care interventions, such as emollients, for primary prevention of eczema and food allergy in infants Secondary objective To identify features of study populations such as age, hereditary risk, and adherence to interventions that are associated with the greatest treatment benefit or harm for both eczema and food allergy. Search methods: We searched the following databases up to July 2020: Cochrane Skin Specialised Register, CENTRAL, MEDLINE, and Embase. We searched two trials registers and checked reference lists of included studies and relevant systematic reviews for further references to relevant randomised controlled trials (RCTs). We contacted field experts to identify planned trials and to seek information about unpublished or incomplete trials. Selection criteria: RCTs of skin care interventions that could potentially enhance skin barrier function, reduce dryness, or reduce subclinical inflammation in healthy term (> 37 weeks) infants (0 to 12 months) without pre-existing diagnosis of eczema, food allergy, or other skin condition were included. Comparison was standard care in the locality or no treatment. Types of skin care interventions included moisturisers/emollients; bathing products; advice regarding reducing soap exposure and bathing frequency; and use of water softeners. No minimum follow-up was required. Data collection and analysis: This is a prospective individual participant data (IPD) meta-analysis. We used standard Cochrane methodological procedures, and primary analyses used the IPD dataset. Primary outcomes were cumulative incidence of eczema and cumulative incidence of immunoglobulin (Ig)E-mediated food allergy by one to three years, both measured by the closest available time point to two years. Secondary outcomes included adverse events during the intervention period; eczema severity (clinician-assessed); parent report of eczema severity; time to onset of eczema; parent report of immediate food allergy; and allergic sensitisation to food or inhalant allergen. Main results: This review identified 33 RCTs, comprising 25,827 participants. A total of 17 studies, randomising 5823 participants, reported information on one or more outcomes specified in this review. Eleven studies randomising 5217 participants, with 10 of these studies providing IPD, were included in one or more meta-analysis (range 2 to 9 studies per individual meta-analysis). Most studies were conducted at children's hospitals. All interventions were compared against no skin care intervention or local standard care. Of the 17 studies that reported our outcomes, 13 assessed emollients. Twenty-five studies, including all those contributing data to meta-analyses, randomised newborns up to age three weeks to receive a skin care intervention or standard infant skin care. Eight of the 11 studies contributing to meta-analyses recruited infants at high risk of developing eczema or food allergy, although definition of high risk varied between studies. Durations of intervention and follow-up ranged from 24 hours to two years. We assessed most of this review's evidence as low certainty or had some concerns of risk of bias. A rating of some concerns was most often due to lack of blinding of outcome assessors or significant missing data, which could have impacted outcome measurement but was judged unlikely to have done so. Evidence for the primary food allergy outcome was rated as high risk of bias due to inclusion of only one trial where findings varied when different assumptions were made about missing data. Skin care interventions during infancy probably do not change risk of eczema by one to two years of age (risk ratio (RR) 1.03, 95% confidence interval (CI) 0.81 to 1.31; moderate-certainty evidence; 3075 participants, 7 trials) nor time to onset of eczema (hazard ratio 0.86, 95% CI 0.65 to 1.14; moderate-certainty evidence; 3349 participants, 9 trials). It is unclear whether skin care interventions during infancy change risk of IgE-mediated food allergy by one to two years of age (RR 2.53, 95% CI 0.99 to 6.47; 996 participants, 1 trial) or allergic sensitisation to a food allergen at age one to two years (RR 0.86, 95% CI 0.28 to 2.69; 1055 participants, 2 trials) due to very low-certainty evidence for these outcomes. Skin care interventions during infancy may slightly increase risk of parent report of immediate reaction to a common food allergen at two years (RR 1.27, 95% CI 1.00 to 1.61; low-certainty evidence; 1171 participants, 1 trial). However, this was only seen for cow's milk, and may be unreliable due to significant over-reporting of cow's milk allergy in infants. Skin care interventions during infancy probably increase risk of skin infection over the intervention period (RR 1.34, 95% CI 1.02 to 1.77; moderate-certainty evidence; 2728 participants, 6 trials) and may increase risk of infant slippage over the intervention period (RR 1.42, 95% CI 0.67 to 2.99; low-certainty evidence; 2538 participants, 4 trials) or stinging/allergic reactions to moisturisers (RR 2.24, 95% 0.67 to 7.43; low-certainty evidence; 343 participants, 4 trials), although confidence intervals for slippages and stinging/allergic reactions are wide and include the possibility of no effect or reduced risk. Preplanned subgroup analyses show that effects of interventions were not influenced by age, duration of intervention, hereditary risk, FLG mutation, or classification of intervention type for risk of developing eczema. We could not evaluate these effects on risk of food allergy. Evidence was insufficient to show whether adherence to interventions influenced the relationship between skin care interventions and risk of developing eczema or food allergy. Authors' conclusions: Skin care interventions such as emollients during the first year of life in healthy infants are probably not effective for preventing eczema, and probably increase risk of skin infection. Effects of skin care interventions on risk of food allergy are uncertain. Further work is needed to understand whether different approaches to infant skin care might promote or prevent eczema and to evaluate effects on food allergy based on robust outcome assessments.
Article
Background: Infants with neonatal abstinence syndrome (NAS) are at an increased risk for diaper dermatitis, which can cause skin breakdown and lead to significant pain and potential infection exposure. Skin care protocols in the neonatal intensive care unit (NICU) setting seldom specifically address the needs of this at-risk population, leading to inconsistent skin care management. Purpose: The goal was to support a decrease in the rate of diaper dermatitis for infants with NAS by designing and implementing an evidence-based skin care protocol. Methods: A retrospective medical record review was used to examine outcomes of 25 infants preintervention and 8 infants postintervention. The skin care protocol was a bundle of 5 evidence-based interventions: (1) a specific diaper dermatitis assessment tool; (2) frequent diaper changes with superabsorbent diapers; (3) application of petroleum jelly and alcohol-free wipes; (4) infant bathing in pH neutral soap; and (5) application of zinc oxide barrier cream for erythema. Results: There was an overall 80.5% decrease in diaper dermatitis from pre- to postimplementation (P ≤ .01) as noted when comparing positive cases of diaper dermatitis with negative cases from pre- to postintervention. Implications for practice: Expanding the skin care protocol to all neonates in the NICU and nursery could aid in maintaining skin integrity and decreasing diaper dermatitis in the NICU. More research is needed following this study for the data to be generalizable to other NICUs. This study offers key takeaways including using a specific diaper dermatitis assessment tool and consistently using the bundle of interventions.Video Abstract Available at:https://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?autoPlay=false&videoId=47.
Article
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Background Skin barrier functions develop after birth and may be related to skin disorders in infants. We aimed to assess associations between dynamic trends of four skin barrier functional parameters in early life with infant atopic dermatitis (AD). Methods Based on the prospective cohort MKNFOAD (NCT02889081), we examined transepidermal water loss (TEWL), stratum corneum hydration (SCH), skin pH, and sebum content at five anatomical sites (cheek, forehead, forearm, abdomen, and lower leg) in 418 term infants at birth, 42 days, and 6 months. Trend differences by sex and association with AD at age 1 year were tested using variance analyses. Associations of the parameters with AD risk were tested using discrete time survival analysis, adjusting extensive covariates including parental history of allergy, infant’s sex, birth weight (kg), and delivery mode. Odds ratios (ORs) and 95% confidence interval (CIs) were reported. Results Overall TEWL and SCH appeared trends of increase while skin surface pH and sebum content showed trends of decrease within the first six postnatal months. Sex differences were significant for sebum content only (p < 0.001). After adjustment for parental and children covariates, cheek TEWL at birth (OR = 1.26, 95% CI 1.00–1.57, p = 0.045) and 42 days (OR = 1.52, 95% CI 1.17–1.97, p = 0.002) were significantly associated with increased AD risk. Associations were not observed between SCH, skin pH, and sebum content at birth or 42 days with AD. Conclusions Skin barrier functions of Chinese term infants varied nonlinearly after birth. Higher postnatal TEWL levels in early life indicate higher risk of early-onset AD.
Article
Noncontact camera-based methods for measuring the pulse rate have been introduced in recent years. However, in previous studies, pulse-rate measurement experiments have been conducted only for adults and/or sleeping infants, and not for infants, who are awake. In this study, we compare the principal noncontact camera-based methods for pulse-rate measurement and identify a suitable method for infants, who are awake. We measure the pulse rate of five adults and three infants, and obtain the success rate of setting the measurement region and the root mean square error (RMSE) of the estimated pulse rate using several existing methods. Based on the obtained results, the color-based method and independent component analysis are determined as the most suitable for setting the measurement region and for signal processing, respectively, for infants, who are awake.
Article
Full-text available
The article provides information about the features of the structure, development and differentiated approach to the appointment of dexapanthenol preparations used for the prevention and complex treatment of skin diseases in children of wounded age. Regular use of leave-on cosmetic products including body creams and lotions is very high among children aged 0–4 years. However, in most cases, recommendations for the use of topical baby skin care medicinal products and/or cosmetic products are based not on scientific evidence, but on common sense, expert opinions, advertising, personal preferences of parents, pharmacists, dermatologists and/or pediatricians. For example, adsorbing properties of baby powders are insufficient, and after absorbing moisture, they actually turn to “urine compresses” that aggravate the epidermis injury. After swelling, the starch-containing powders represent an excellent growth media for pathogenic and opportunistic microflora. It is noted that only proper skin care for young children allows you to preserve its integrity and functional state. Special attention is paid to the preparations of the Bepanten® series in the form of cream and ointment, which meet all the criteria for topical products, and can be used for the prevention and treatment of skin diseases in young children, effectively protecting the skin from irritants, promoting its healing and recovery, having an anti-inflammatory effect, increasing its elasticity, elasticity and are recommended for use as a means of basic care. Their effectiveness has been repeatedly confirmed in the numerous domestic and foreign randomized controlled studies in new-born populations at different gestational ages, which provided the scientific justification for their common use in the ‘real-life’ practice of pediatricians, dermatologists and allergists.
Chapter
The outermost structure of the epidermis is the stratum corneum, and it forms the epidermal permeability barrier which prevents the loss of water and electrolytes. Corneocytes are formed by the terminal differentiation of the keratinocytes from the granular layer of the epidermis. Lamellar granules or bodies (LG or LB) are specialized lipid carrying vesicles formed in suprabasal keratinocytes, destined for delivery of the lipids in the interface between the corneocytes. Keratohyalin granules are irregularly shaped granules present in the granular cells of the epidermis, thus providing these cells the granular appearance. Epidermis also generates a spectrum of antimicrobial lipids, peptides, nucleic acids, proteases, and chemical signals that together forms the antimicrobial barrier. Epidermal lipids, the integral components of the permeability barrier, are synthesized and secreted by the keratinocytes in the stratum granulosum after processing and packaging into the LB. The human skin is constantly exposed to hostile environment.
Article
Résumé Les pédiatres francophones constatent, depuis quelques années, une augmentation inquiétante des cas d’allergies alimentaires et d’anaphylaxies chez des enfants de plus en plus jeunes avec polyallergies et polysensibilisations, portant sur des allergènes à haut potentiel anaphylactique comme l’arachide et les fruits à coques et impactant grandement la qualité de vie et le futur de ces enfants. En partant des données épidémiologiques actuelles, nous reprenons les principales causes de l’augmentation des allergies alimentaires ainsi que les données des études sur la barrière cutanée et son rôle fondamental sur l’apparition de sensibilisation(s) puis d’allergie(s) alimentaire(s). Les données concernant la voie digestive tolérogène, sont également rapportées, constituant une voie de prévention majeure. Nous avons également souhaité proposer des pistes sur la prévention de l’allergie aux protéines du lait de vache à partir des études observationnelles existantes. À la lumière de ces études, nous faisons des propositions de prévention, axées sur le nourrisson et concernant l’introduction du lait de vache, la prise en charge active de tout eczéma et la mise en place d’une diversification alimentaire précoce et large incluant les allergènes alimentaires à haut risque anaphylactique tels l’arachide et les fruits à coque, tout en prenant compte les habitudes familiales de consommation alimentaire.
Article
Background/objectives: Some full-term newborns present with erythema and irritation of the buttocks and perianal area as early as the first 4 days of their lives. The effect of moisturizers in protecting this vulnerable skin has not been rigorously studied. This study aimed to clarify whether there is a difference in perianal skin barrier function with and without moisturizer application in the first month of life. Methods: Comparative investigation of 118 full-term newborns was performed, and they were allocated to intervention (n = 63) and control groups (n = 55). The intervention group received moisturizer application to the perianal area, and the control group received care without application of moisturizer to the perianal area from the first day of life until the 1-month visit. Transepidermal water loss (TEWL), stratum corneum hydration (SCH), and skin surface pH in the perianal area were measured as the indicators of skin barrier function on days 1 and 5 after birth and at the 1-month visit. Results: At the 1-month visit, TEWL was significantly decreased (intervention, 19.4 g/m2 /h; control, 25.8 g/m2 /h; p = .00) and SCH was significantly increased (intervention, 58.8 arbitrary units (a.u.); control, 46.5 a.u.; p = .00) in newborns using perianal moisturizer. The skin surface pH was not significantly different. Conclusions: The use of moisturizer was effective in protecting the skin barrier function of the perianal skin. Further investigations are needed to determine the effect on the frequency and extent of rashes in the perianal area.
Article
Our skin is the interface through which we mediate lifelong interactions with our surrounding environment. Initial development of the skin’s epidermis, adnexal structures, and barrier function is necessary for normal cutaneous microbial colonization, immune development, and prevention of disease. Early life microbial exposures can have unique and long-lasting impacts on skin health. The identity of neonatal skin microbes and the context in which they are first encountered, i.e., through a compromised skin barrier or in conjunction with cutaneous inflammation, can have additional short- and long-term health consequences. Here, we discuss key attributes of infant skin and endogenous and exogenous factors that shape its relationship to the early life cutaneous microbiome, with a focus on their clinical implications.
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As the largest organ of the human body the skin offers a protective role, providing a tough but pliable covering that provides the major barrier between the internal organs and the environment. It actively regulates water loss and is both oxygen and carbon dioxide permeable, and influences temperature regulation and immunological functions through its sensory properties. Both intrinsic and enhanced environmental factors contribute to the progressive deterioration of the skin with increasing age. Cutaneous problems are therefore an unavoidable and inevitable consequence of aging skin, which can prove to be both cosmetically unacceptable to those who succumb to these problems, as well as even life threatening if skin breakdown becomes chronic as is case with leg ulceration. This in turn has major implications for long-term impact on those looking after them (e.g., family, carers, etc.) and a huge burden on the health care system.
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The skin of newborns and infants is characterized by structural and functional immaturity. Diaper dermatitis is one of the most common skin conditions in this age period. This condition has a complex and multifactorial etiology. The interaction of several causes, including high humidity under the diaper, skin maceration, and prolonged contact with irritants, leads to destruction of the immature epidermal barrier, microbial invasion, and inflammation. Diaper dermatitis should be differentiated from allergic contact dermatitis, candidiasis, atopic dermatitis, seborrheic dermatitis, psoriasis. Effective measures to prevent diaper dermatitis are to keep the skin dry, reduce friction, limit the time of contact with urine and feces, as well as the topical application of protective products. Today, of all the disposable diapers on the market, the high quality disposable diapers developed and produced by the Japanese company KAO Corporation are proven effective in preventing diaper dermatitis.
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Full-text available
Functional differences between infant and adult skin may be attributed to putative differences in skin microstructure. The purpose of this study was to examine infant skin microstructure in vivo and to compare it with that of adult skin. The lower thigh area of 20 healthy mothers (ages 25-43) and their biological children (ages 3-24 months) was examined using in vivo noninvasive methods including fluorescence spectroscopy, video microscopy, and confocal laser scanning microscopy. Stratum corneum and supra-papillary epidermal thickness as well as cell size in the granular layer were assessed from the confocal images. Adhesive tapes were used to remove corneocytes from the outer-most layer of stratum corneum and their size was computed using image analysis. Surface features showed differences in glyph density and surface area. Infant stratum corneum was found to be 30% and infant epidermis 20% thinner than in adults. Infant corneocytes were found to be 20% and granular cells 10% smaller than adult corneocytes indicating a more rapid cell turnover in infants. This observation was confirmed by fluorescence spectroscopy. Dermal papillae density and size distribution also differed. Surprisingly, a distinct direct structural relationship between the stratum corneum morphology and the dermal papillae was observed exclusively in infant skin. A change in reflected signal intensity at approximately 100 mum indicating the transition between papillary and reticular dermis was evident only in adult skin. We demonstrate in vivo qualitative and quantitative differences in morphology between infant and adult skin. These differences in skin microstructure may help explain some of the reported functional differences.
Article
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Factors that may influence the water transport through the skin in infants on their first day of life were studied with a method based on determination of the vapour pressure gradient in the air layer close to the skin surface. The evaporation rate from the skin was found to vary with the site of measurement, ambient humidity, temperature, activity, gestational age and nutritional status at birth. Differences related to maturity were shown to decrease with postnatal age. © 1981 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.
Article
Fluorescence excitation spectroscopy was used to assess cellular turnover in human skin by monitoring changes of endogenous fluorescence. Epidermal proliferation was induced with α‐hydroxy acids. Commercially available glycolic acid creams (8 and 4% wt/wt concentration) and a vehicle cream (placebo) were applied in a randomized double blinded fashion on subjects' forearms, twice daily for 21 days. Excitation spectra were recorded (excitation 250–360 nm, emission 380 nm) at days 0, 1, 3, 7, 10, 11, 14, 17 and 21. The 295 nm excitation band (assigned to tryptophan moieties) was used in this study as a marker for cellular proliferation. To further reduce the day‐to‐day variability of the skin fluorescence the intensity of the 295 nm band was normalized to the 334 nm band (assigned to collagen crosslinks). The fluorescence emission intensity from placebo‐treated skin remained practically unchanged over the period of the measurements while the fluorescence intensity measured from the glycolic acid–treated skin increased monotonically with treatment. The rate of increase of the excitation intensity with treatment was found to be dose dependent. The epidermal 295 nm band may be used as a quantitative marker to monitor the rate of proliferation of epidermal keratinocytes noninvasively.
Article
• Electrical impedance, which is the resistance to an alternating current, is a parameter that is used to determine the condition of the electrode-skin interface before evoked potentials are recorded. High electrical impedance can result in inaccurate interpretation of evoked potentials due to excessive artifacts. This study investigated the electrical skin impedance in 36 full-term infants who ranged from 0 to 1 year of age to delineate the temporal relationship between skin maturation and skin impedance. Correlation and regression analyses demonstrated a statistically significant inverse relationship between electrical skin impedance and age during the first year of life. This drop in skin impedance during the first few postnatal months was attributed to an increase in skin hydration as a result of the greater functional maturity of eccrine sweat glands. (Arch Dermatol. 1989;125:647-650)
Article
An automated confocal Raman microspectrometer for rapid measurement of molecular concentration profiles in the skin is described. It permits the successive collection of Raman spectra at a range of depths below the skin surface. The axial resolution of the confocal Raman microspectrometer is 5.1±0.2 µm. The setup was applied to determine water concentration profiles of the stratum corneum and to determine changes therein as a result of hydration of the skin. Copyright © 2000 John Wiley & Sons, Ltd.
Article
In vivo, noninvasive, transepidermal water loss measurements were taken from 26- to 41-week gestational age infants with a Meeco® electrolytic water analyzer to yield information on the development of the function of the skin barrier. Infants 28 weeks or less have significantly greater transepidermal water loss than older gestational aged infants, thus indicating a less efficient barrier to water. Until it is known whether the decreased barrier function in premature infants also relates to percutaneous penetration, prudence is suggested in exposing such premature infants skin to chemicals.
Article
This project aimed to quantify the regional distribution of sweat composition over the skin surface and to determine whether sweat constituent concentrations collected from regional sites can estimate whole-body concentrations. Ten males cycled for 90 min in a 20°C (50 % relative humidity) environment at 45 % peak aerobic power. Sweat was collected from eleven skin regions and the whole body, using a wash-down technique. Strong relationships were evident between the regional and whole-body sweat [Na+] and [Cl-], such that the thigh and calf exhibited greater correlation coefficients than area-weighted means derived from four and eight skin regions. Therefore, in this particular protocol the whole-body sweat [Na+] and [Cl-] could be predicted from regional sweat collections. Relationships between sweat constituents were evident for sweat [Na+] and pH, and sweat [K+] and [lactate] when data were pooled between skin regions and subjects. To our knowledge this is the first investigation to report a positive relationship between sweat [K+] and [lactate]. The exact mechanism responsible for the positive relationship between sweat [K+] and [lactate] is uncertain although it is speculated to occur at the secretory coil.
Article
Time- and site-dependent differences in epidermal barrier properties were investigated over the first 28 days of life in healthy term newborn infants. Diapered and nondiapered skin sites were contrasted to the volar forearm of adults (mothers). Thirty-one term infants were evaluated in the hospital on postnatal day 1 and at home on days 4, 7, 14, 21, and 28 for a total of six visits. Measurements included baseline skin hydration, continuous capacitive reactance, peak water sorption, rate of water desorption, skin pH, skin temperature, and environmental conditions. Changes in epidermal barrier properties over the first 4 weeks of life included an increase in surface hydration, a decrease in transepidermal water movement under occlusion, a decrease in surface water desorption rate, and a decrease in surface pH. Diapered and nondiapered regions were indistinguishable at birth but exhibited differential behavior over the first 14 days, with the diapered region showing a higher pH and increased hydration. Maternal measurements remained constant throughout the period. We conclude that healthy newborn skin undergoes progressive changes in epidermal barrier properties over the first 28 days. Adult skin testing does not replicate newborn skin during the first month of life.
Article
Insensible water loss (IWL) is an important factor in the thermoregulation and water balance of the newborn infant. A method for direct measurement of the rate of evaporation from the skin surface has been developed. The method, which is based on determination of the vapour pressure gradient close to the skin surface, allows free evaporation. From measurements performed on 19 newborns placed in incubators, a linear relation was found between the evaporation rate (ER) and the humidity of the environment at a constant ambient temperature. A 40% lower ER was recorded at a high relative humidity (60%) than at a low one (20%) in the incubator. At measurements on different sites of the body, a high ER was observed on the face and peripheral parts of the extremities, while ER at other sites was relatively low. By determining ER from different parts of the body and calculating the areas of the corresponding surfaces, the total cutaneous insensible water loss for the infant in question could be obtained. The transepidermal water loss (TEWL) for the whole body surface area was calculated to be 8.1 g/m2h. On the basis of measurements performed it was found that the total cutaneous insensible water loss can be estimated with a reasonable degree of accuracy by recording ER from only three easily accessible measurement points.
Article
The improvement of stratum corneum hydration is one of the most important claims in the cosmetic industry. Objective assessment of moisturization can be done with devices based on electrical methods provided these instruments are used in an appropriate manner. This paper deals with the biophysical basis behind these techniques and describes the most important variables, pitfalls and drawbacks related to measurements and current instrumentation. Individual-related and environment-related variables are also analyzed as well as study designs for predictive or use tests. Practical suggestions for standardization of measurements are given.
Article
Animal models are important tools for studies in skin physiology and pathophysiology. Due to substantial differences in skin characteristics such as thickness and number of adnexa, the results of animal studies cannot always be directly transferred to the human situation. Therefore, transplantation of human skin on to SCID (severe combined immunodeficiency) mice might offer a promising tool to perform studies in viable human skin without the direct need for human volunteers. To characterize the physiological and anatomical changes of a human skin transplant on a SCID animal host. In this study human skin was transplanted on to 32 SCID mice and followed for 6 months. Barrier function was assessed by transepidermal water loss (TEWL; tewametry) and moisture content of the stratum corneum was studied by measurement of electrical capacitance (corneometry). The results showed considerable deviations of TEWL values and skin hydration between the grafts and human skin in vivo. The human skin showed epidermal hyperkeratosis and moderate sclerosis of the corium 4 and 6 months after transplantation on to SCID mice. Our results indicate that human skin does not completely preserve its physiological and morphological properties after transplantation on to SCID mice. Therefore, results from experiments using this model system need to be discussed cautiously.
Article
Based on recent morphologic, histochemical, and biochemical data, we propose a heterogeneous two-compartment model of the stratum corneum that ascribes a special role for intercellular lipids in the regulation of stratum corneum barrier function and desquamation. The evidence in favor of the model and several predictions based on the model are surveyed in this review.
Article
Malignant melanoma is a rare neoplasm in the pediatric population, but its incidence has risen in recent years. The literature was reviewed to define the current clinical and pathologic features of pediatric melanoma, highlighting the similarities and differences between adult and pediatric melanoma. Distinctive features of this disease, including frequency and type of genetic abnormalities, predisposing conditions, clinical presentation, stage at diagnosis, prognostic features, and frequency of sentinel lymph node positivity are emphasized. Treatment strategies, extrapolated from adult melanoma trials, are also discussed. Despite the differences between pediatric and adult melanoma, survival rates are similar and are improving in both populations. Further studies will help delineate the pathogenesis of both adult and pediatric melanoma, with the goal of contributing to early detection and improved survival.
Article
The effects of specific species of skin bacteria on human sebaceous gland lipids in vitro were analyzed. Isolated dissected sebaceous glands were pooled, homogenized, and sterilized, then incorporated into peptone-yeast extract medium and used as substrate for growth of Propionibacterium acnes, P. granulosum, and Staphylococcus epidermidis subgroup II. The sebaceous lipids were analyzed by thin-layer chromatography before and after bacterial growth. The most striking effect of bacteria on sebaceous gland lipid composition was the hydrolysis of sebaceous triglycerides. The degree of hydrolysis varied with bacterial strain but was most complete with P. acnes and P. granulosum. Staphylococci were not effective in hydrolyzing sebaceous triglycerides at pH 4.5 although, when the pH of the medium was raised to pH 6.4, some strains of staphylococci were as effective as the propionibacteria in hydrolyzing sebaceous triglycerides to free fatty acids. Thus minor changes in acidity may play asignificant role in controlling the lipolytic activity of staphylococci on skin. Another effect of bacterial action on sebaceous gland lipids was the esterification of sebaceous cholesterol to cholesteryl esters. Thus, bacterial action must be taken into account in evaluating studies of alterations in cutaneous cholesterol and cholesteryl esters in skin surface lipids in normal and disease states.
Article
Using a method described in a previous article the transepidermal water loss (TEWL) was studied in 10 healthy newborn infants at rest and during activity. On the average TEWL was 37% higher during activity than during rest although no sweating was observed. In 9 infants placed in incubators with an ambient temperature slightly above the thermoneutral range measurements were made as the body temperature rose. TEWL was almost constant until a temperature of 37.1 degrees C was reached whereupon the water loss suddenly increased as the infant started sweating.
Article
The photoprotective role of melanin was evaluated by comparing the transmission of ultraviolet (UV) radiation through skin samples of blacks and Caucasians, using both biologic and spectroscopic techniques. UVA transmission was measured using fluoranthene, which causes a phototoxic response to UVA wavelength. UVB was measured by monitoring erythema produced by either a 150-watt xenon arc or FS-20 sunlamps. It was found that on the average, five times as much ultraviolet light (UVB and UVA) reaches the upper dermis of Caucasians as reaches that of blacks. Differences in transmission between the stratum corneum of blacks and of Caucasians were far less striking. The main site of UV filtration in Caucasians is the stratum corneum, whereas in blacks it is the malpighian layers. Melanin acts as a neutral density filter, reducing all wavelengths of light equally. The superior photoprotection of black epidermis is due not only to increased melanin content but also to other factors related to packaging and distribution of melanosomes. Not only are these data consistent with epidemiologic evidence, but they also may indicate why blacks are less disposed to phototoxic drug responses as well as less susceptible to acute and chronic actinic damage.
Article
Using a method described earlier, the evaporation rate (ER) was studied at different humidities in 12 newborn infants born after 25 to 30 weeks of gestation and 10 infants born after 32 to 35 weeks. Transepidermal water loss (TEWL) was estimated in 32 infants born after 25 to 39 weeks of gestation. The ER values were highest in the infants with the lowest gestational age and the susceptibility to changes in ambient humidity was also greater at lower gestational ages. An exponential relationship was found between TEWL and gestational age. TEWL being 15 times higher in infants born after 25 weeks of gestation than in full-term infants.
Article
Insensible water loss (IWL) is an important factor in the thermoregulation and water balance of the newborn infant. A method for direct measurement of the rate of evaporation from the skin surface has been developed. The method, which is based on determination of the vapour pressure gradient close to the skin surface, allows free evaporation. From measurements performed on 19 newborns placed in incubators, a linear relation was found between the evaporation rate (ER) and the humidity of the environment at a constant ambient temperature. A 40% lower ER was recorded at a high relative humidity (60%) than at a low one (20%) in the incubator. At measurements on different sites of the body, a high ER was observed on the face and peripheral parts of the extremities, while ER at other sites was relatively low. By determining ER from different parts of the body and calculating the areas of the corresponding surfaces, the total cutaneous insensible water loss for the infant in question could be obtained. The transepidermal water loss (TEWL) for the whole body surface area was calculated to be 8.1 g/m2h. On the basis of measurements performed it was found that the total cutaneous insensible water loss can be estimated with a reasonable degree of accuracy by recording ER from only three easily accessible measurement points.
Article
Our clinical observations disclosed that most newborn infants showed scaling on at least some parts of the body. To clarify the mechanism for such xerosis, we performed measurements of high-frequency conductance (Gx), which assesses the skin surface hydration and evaporative water loss from the skin. The skin of newborns showed surprisingly lower Gx values and evaporative water loss than those of adults or 1- to 6-month-old infants in a warm environment. These findings may be explained partly by low eccrine activity, which has been reported as characteristic of newborn skin. However, defective stratum corneum function, such as reduced water-holding capacity as demonstrated by the in vivo water sorption-desorption test, also seems to be responsible for the development of dry skin in newborns.
Article
Skin cleansing preparations consisting of identical synthetic detergents but differing in pH-value (pH 5.5 and 7.0) were applied twice daily on the forehead and forearm of healthy volunteers in a randomized crossover trial. The skin surface pH was found to be significantly higher when the neutral preparation had been used, as was the propionibacterial count (p less than 0.05). The number of propionibacteria was significantly linked to the skin pH. Hence even minor differences in the pH of skin cleansing preparations seem to be of importance for the integrity of the skin surface. This should be taken into account when planning the formulation of optimal skin care products.
Article
Hydration and the water-retention capacity of stratum corneum have been investigated in uninvolved psoriatic and atopic skin and compared with that of healthy controls. Thirty-three subjects of either sex and matched for age entered the study. The subjects were free from all signs of skin disease and skin dryness. Hydration was evaluated by means of transepidermal water loss and skin capacitance measurements. Water-retention capacity was investigated using the plastic occlusion stress test. Atopic skin differed significantly from uninvolved psoriatic and control skin which had a reduced water content and an increased transepidermal water loss. Furthermore, the skin surface water loss profile representing the stratum corneum water-retention capacity was significantly lower in normal atopic skin. The data suggest that clinically normal skin may be functionally abnormal, resulting in a defective barrier that could lead to higher risk of irritant or contact dermatitis.
Article
Experiments on skin moisture, i.e. the hydration state of the outer epidermis, were undertaken using three different types of equipment, i.e. the Skicon-100 and Corneometer CM 420 hydrometers and the Servo Med EPI evaporimeter. The studies included 10 healthy volunteers. Water was applied to test sites on the forearm and the palm of the hand, and effects monitored by the three methods. Parallel increases in conductance, capacitance and transepidermal water loss were registered for a duration of about 5 min. The Skicon-100 was more sensitive for measurement of increased hydration, while the Corneometer CM 420 might be more sensitive for measurement of decreased hydration. Inter- and intra-individual variations were minor with all instruments. According to reproducibility studies, the Corneometer CM 420 was more accurate than the Skicon-100. Technical experiments indicated that the Corneometer CM 420 depicts changes of hydration down to a depth of 0.1 mm, while the Skicon-100 measures very superficially. In conclusion, both hydrometers were deemed relevant and valid for assessment of skin moisture. The methods are complementary, and their combined use is recommended.
Article
Electrical impedance, which is the resistance to an alternating current, is a parameter that is used to determine the condition of the electrode-skin interface before evoked potentials are recorded. High electrical impedance can result in inaccurate interpretation of evoked potentials due to excessive artifacts. This study investigated the electrical skin impedance in 36 full-term infants who ranged from 0 to 1 year of age to delineate the temporal relationship between skin maturation and skin impedance. Correlation and regression analyses demonstrated a statistically significant inverse relationship between electrical skin impedance and age during the first year of life. This drop in skin impedance during the first few postnatal months was attributed to an increase in skin hydration as a result of the greater functional maturity of eccrine sweat glands.
Article
Filaggrin is a specific epidermal protein which is the precursor of the free amino acids, urocanic acid and pyrrolidone carboxylic acid which are largely responsible for the ability of the stratum corneum of the skin to remain hydrated at low environmental humidity. The distribution of filaggrin shown by immunofluorescence in the stratum corneum of the rat changed dramatically during the first hours of postnatal life. During late foetal development, filaggrin accumulated through the entire thickness of the stratum corneum, indicating that there was a block on the subsequent processing of the protein which normally would convert it to free amino acids. Immediately after birth this block was lifted and normal proteolysis of the filaggrin took place in the outer part of the stratum corneum, leaving the normal adult pattern of a thin zone of cells containing filaggrin at the bottom of the stratum corneum. This activation of filaggrin proteolysis was dependent on the drop in external water activity caused by the transition from an aqueous environment in utero to a dryer environment after birth and it could be blocked by maintaining a 100% humidity atmosphere around the newborn rat after birth. In isolated stratum corneum in vitro, filaggrin proteolysis took place only between 80 and 95% relative humidity, both higher and lower relative humidity blocked the proteolysis. Application of occlusive patches to adult rats prevented the normal proteolysis of filaggrin, indicating that this mechanism controls not only the massive filaggrin proteolysis occurring after birth but also the proteolysis occurring during normal stratum corneum maturation. The stratum corneum therefore has the ability to respond to changes in external humidity by altering the level of the stratum corneum where it converts its reserves of filaggrin into water binding amino acids, such that under humid conditions water binding components will be produced in only the most superficial stratum corneum, or even not produced at all.
Article
Histological development of the epidermis was studied on skin samples from 169 infants (gestation 24-40 weeks, age up to 1 year). Gestation markedly influenced epidermal development. Before 30 weeks, the epidermis is thin, has few cell layers and a poorly formed stratum corneum, but by 34 weeks it has largely matured. Postnatal influence on epidermal development is marked in the preterm infant, so that histologically the epidermis of the most immature infant resembles that of a term infant by 2 weeks of age. These changes in histology exactly parallel the development of the barrier properties of newborn skin.
Article
Today, the term "normal skin pH" is understood to be the pH value of the surface of the skin of the lower arm of a healthy adult male Caucasian. Its mean value lies in the range 5.4-5.9. In most cases, it is determined by means of a flat glass electrode. The parameter "skin pH" depends mainly on the area of skin and on age, but it also depends to a lesser extent on sex, race and the time of day when values are determined.
Article
THE postnatal development of the sweating mechanism is still incompletely understood. The basis for the presumed delay in the onset of sweating in full-term neonates is as puzzling as the reason why prematurely born infants are unable to sweat for some time after birth. Neonatal sweating deficiency is cited as an example of functional immaturity, but the state of the development of the component parts of this mechanism—sweat glands, peripheral neural pathways, and automic centers—is unknown. With few exceptions, the available data on neonatal sweating concern thermal reflex sweating, which depends upon the functional status of the glands proper and on the competence of the nervous elements comprising the reflex arc. Recent studies have provided evidence, direct1 and indirect,2 of the mature neonate's ability to sweat naturally on the first day of life, earlier than was generally believed.3 On the other hand, thermal sweating is a unique
Article
The barrier properties of the skin were examined in 223 studies in 70 newborn infants of 25 to 41 weeks' gestation, aged from 1 hour to 26 days. Percutaneous drug absorption was studied by observing the blanching response to solutions of 1% and 10% phenylephrine applied to a small area of abdominal skin. Skin water loss was measured at the same site using an evaporimeter. Infants of 37 weeks' gestation or more showed little or no drug absorption and had low skin water losses, indicating that their skin is an effective barrier. By contrast, infants of 32 weeks' gestation or less showed marked drug absorption and high skin water losses in the early neonatal period, indicating that their skin is defective as a barrier. Both drug absorption and water loss in these infants fell steadily; by about 2 weeks of age the skin of the most immature infants functioned like that of mature infants. The varying barrier properties can be explained by the poor development of the stratum corneum in the more premature infants at birth and its rapid maturation after birth. The trauma caused to the skin by use of adhesive tape and the fixation of transcutaneous oxygen electrodes resulted in increased drug absorption and water loss from the damaged area.
Article
We compared the thickness of the stratum corneum from abdominal skin in infants less than 3 months of age, children between 3 months and 11 years, and adults. Measurements were made with a filar micrometer eyepiece on histologic sections obtained at autopsy. No significant differences were seen; therefore, a stratum corneum of different thickness cannot be used to explain differences in percutaneous absorption, supporting previous work which suggested that term infants and children have an efficient skin barrier. The greater toxicity from percutaneous absorption of topical compounds sometimes seen in children is more likely due to their increased surface to volume ratio and/or metabolic differences.
Article
Based on the evidence from previous studies that the hydration state of the skin surface can be evaluated quickly and quantitatively in terms of conductance to the high frequency electric current of 3.5 MHz, a simple in vivo function test has been established that furnishes information on the hygroscopic property and water-holding capacity of the stratum corneum in a few minutes. The test procedure consists of electromeasurements before and after application of a droplet of water on the skin for 10 seconds to obtain data on the hygroscopic property of the skin surface and later serial measurements at an interval of 30 seconds for 2 minutes to evaluate the water-holding capacity. Under usual ambient conditions normal skin surface showed a high rise in conductance just after application of water, which was followed by a rapid fall-off within 30 seconds, thereafter by gradual return to the pregydration levels by 2 min. By this method we have demonstrated that (i) the superficial horny layer of normal skin is much less hygroscopic and less capable of holding water than te corresponding deeper portions and that (ii) scaly skin shows functional defects in both hygroscopicity and water-holding capacity, between which the former normalizes much faster than the latter.
Article
The reproducibility of the pulsed ultrasound technique for the determination of skin thickness was investigated, using two independent observers. No systematic difference was found and a high correlation was obtained. Studies were also undertaken to validate the pulsed ultrasound technique as a measure of true skin thickness. Skin thickness determined in vitro was found to be greater than when in vivo determinations were made by either the pulsed ultrasound or a xeroradiographic technique, probably due to the release of in vivo tension within the dermis after excision. Skin thickness was found to increase linearly with age up to the age of 20 years and to decrease linearly with age subsequently. Differences in skin thickness between the sexes and in different sites of the body were demonstrated.