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The effect of environmental humidity and temperature on skin barrier function and dermatitis
Abstract
Physicians are aware that climatic conditions negatively affect the skin. In particular, people living in equator far countries such as the Northern parts of Europe and North America are exposed to harsh weather during the winter and may experience dry and itchy skin, or deterioration of already existing dermatoses. We searched the literature for studies that evaluated the mechanisms behind this phenomenon. Commonly used meteorological terms such as absolute humidity, relative humidity and dew point are explained. Furthermore, we review the negative effect of low humidity, low temperatures and different seasons on the skin barrier and on the risk of dermatitis. We conclude that low humidity and low temperatures lead to a general decrease in skin barrier function and increased susceptible towards mechanical stress. Since pro-inflammatory cytokines and cortisol are released by keratinocytes, and the number of dermal mast cells increases, the skin also becomes more reactive towards skin irritants and allergens. Collectively, published data show that cold and dry weather increase the prevalence and risk of flares in patients with atopic dermatitis.
... AE can be triggered by several factors, such as food allergens, viral infections, and climate conditions. For example, studies have revealed that symptoms of AE are more common when outdoor temperature, humidity, and ultraviolet (UV) exposure are low (6)(7)(8). Thus, people living in the northern parts of Europe are at a higher risk for experiencing dry and itchy skin when exposed to winter (6). ...
... For example, studies have revealed that symptoms of AE are more common when outdoor temperature, humidity, and ultraviolet (UV) exposure are low (6)(7)(8). Thus, people living in the northern parts of Europe are at a higher risk for experiencing dry and itchy skin when exposed to winter (6). ...
... Several studies have examined the relationship between weather parameters and flare-ups of AE. Although one study has indicated that the burden of AE is higher in summer due to increased sweating (31), the ma- jority of studies have suggested that the risk of AE flares increases with low outdoor temperature (6)(7)(8). February and October were found to be the months with the highest incidence of AE (6). The current study found a negative correlation between search volume and temperature, which also indicates that the need for information and thereby the disease burden were higher in winter. ...
As atopic eczema is triggered by environmental factors, such as temperature, differences in disease burden between and within countries are possible. One method to study this phenomenon is to perform web-search analysis, since the internet is commonly used to retrieve health-related information. This study, investigating the Google search volume regarding eczema in Swedish counties between April 2017 and March 2021, revealed a continuous increase in searches and that the search volume was higher in Northern than Southern Sweden. Gotland had the most searches per 100,000 inhabitants. In general, there was a negative correlation between search volume and temperature (r=–0.315, p < 0.001) and [AQ3] hours of sunshine (r=–0.213, p < 0.001), whereas there was a positive association between search volume and wind (r=0.229, p < 0.001). Search engine analysis is a rapid and cost-effective method of examining search behaviour regarding disease among the general population within a country and, thus, can enable the identification of regions with specific interests and needs.
... After a mass of skin mechanics tests, various mechanical properties of skin are derived [75], such as anisotropy, Young's modulus, stiffness, compressibility, strength, toughness, initial stress, and skin friction coefficient. The stiffness and strength of skin tissue are affected by many factors such as the external environment (humidity, temperature, etc. [77]), different parts of the human body, gender, age, and race. The biological nature of the species, location, orientation, and sex may all introduce variations to skin mechanical properties [78]. ...
... The stiffness and strength of skin tissue are affected by many factors such as the external environment (humidity, temperature, etc., [77]), different parts of the human body, gender, age, and race. The biological nature of the species, location, orientation, and sex may all introduce variations to skin mechanical properties [78]. ...
... However, since the surface of real skin is not perfectly smooth and the surface where wrinkles form is not flat, the model is just a simplification of real skin. [87] The stiffness and strength of skin tissue are affected by many factors such as the external environment (humidity, temperature, etc., [77]), different parts of the human body, gender, age, and race. The biological nature of the species, location, orientation, and sex may all introduce variations to skin mechanical properties [78]. ...
Microneedles (MNs) as a novel transdermal drug delivery system have shown great potential for therapeutic and disease diagnosis applications by continually providing minimally invasive, portable, cost-effective, high bioavailability, and easy-to-use tools compared to traditional parenteral administrations. However, microneedle transdermal drug delivery is still in its infancy. Many research studies need further in-depth exploration, such as safety, structural characteristics, and drug loading performance evaluation. Finite element analysis (FEA) uses mathematical approximations to simulate real physical systems (geometry and load conditions). It can simplify complex engineering problems to guide the precise preparation and potential industrialization of microneedles, which has attracted extensive attention. This article introduces FEA research for microneedle transdermal drug delivery systems, focusing on microneedle design strategy, skin mechanics models, skin permeability, and the FEA research on drug delivery by MNs.
... Given the observed association of high value of MT with uveitis, the possible explanation of relationship between low-value of DTR and uveitis may be that a failure of thermoregulation caused by decreased variability of temperature leads to elevated temperature-related morbidity (Luo et al. 2013). As for RH, previous researches have reported that low humidity may serve as an environmental risk factor for several seasonrelated exacerbation/amelioration of inflammatory disorders, such as psoriasis and atopic dermatitis (Chandran and Raychaudhuri 2010;Engebretsen et al. 2016). Moreover, the linkage between low humidity and eye complaints has also been revealed. ...
... Similarly, our present study indicated that exposure to low-value of RH was associated with increased risk of hospital admissions for uveitis. Experiments regarding cutaneous inflammatory diseases further revealed that low humidity may promote the sensitivity and inflammation via mast cell hypertrophy and degranulation (Denda et al. 1998;Engebretsen et al. 2016). Contradictorily, an ecological study in Southern Europe showed that uveitis was more frequently to occur in rainy and windy conditions (r = 0.612, p = 0.04 Fig. 4 Single-day lag associations between high mean temperature (75th percentile, 24.5℃) (A), low relative humidity (1th percentile, 44%) (B), low diurnal temperature range (25th percentile, 5.4℃) (C), and hospital admissions for uveitis in different subgroups for the number of rainy days per month; r = 0.469, p = 0.02 for the average wind speed) (Gómez-Mariscal et al. 2020). ...
Meteorological variables are regarded as risk factors for inflammatory diseases, but their associations with uveitis, one of the leading causes accounting for blindness worldwide with an estimated prevalence of 38–714 cases/100,000 person-years, have not been thoroughly investigated. The present study explored the short-term association between meteorological variables and hospital admissions for uveitis in Hefei City, China. Daily data on uveitis hospital admissions and meteorological variables including mean temperature (MT) (°C), diurnal temperature range (DTR) (°C), and relative humidity (RH) (%), from 2014 to 2020, were collected. A time-series study using generalized linear model combined with distributed lag non-linear model was applied. Totally, 1911 admissions for uveitis including 894 first admissions and 1017 readmissions were reported during the study period. The associations of high percentile of MT (75th, 24.5℃) and low percentile of DTR (25th, 5.4℃) with uveitis admissions were observed to be statistically significant from lag9 (RR = 1.041, 95%CI: 1.002–1.081) to lag11 (RR = 1.053, 95%CI: 1.003–1.104) and lag4 (RR = 1.053, 95%CI: 1.019–1.088) to lag5 (RR = 1.052, 95%CI: 1.020–1.085), respectively. Moreover, a significant association between low percentile of RH (1th, 44%) and uveitis admissions appeared at lag0–8 (RR = 1.869, 95%CI: 1.017–3.434) and lasted until lag0–13 (RR = 2.539, 95%CI: 1.102–5.850) in the cumulative lag structure. Subgroup analyses indicated that males and the young seemed to be more sensitive to high MT exposure, while females appeared to be more vulnerable to low DTR exposure. Interestingly, both the young and the elderly are susceptible to low DTR and low RH exposure. Furthermore, high MT and low DTR exposure were associated with increased risk of first admission for uveitis. In summary, exposure to high-value of MT and low-value of DTR and RH may increase the hospital admissions for uveitis, especially for the status of first admission.
... Cold environmental conditions could exert a negative effect on the skin. People exposed to severe weather in winter may experience dry and itchy skin, or their existing skin diseases may worsen [46,47]. Therefore, the improvement effect of A and B may be masked by seasonal changes. ...
Sensitive skin is described as an unpleasant sensory response to a stimulus that should not cause a sensation. Sensitive skin affects an increasing proportion of the population. Sixty-seven participants who tested positive to lactic acid sting test were recruited and randomized into two groups to observe the clinical efficacy and safety of a new birch juice spray for repairing sensitive skin. One group used test spray A, while the other group used spray B as a control. Both groups were sprayed six times daily for 28 days. Noninvasive testing instruments were used to measure stratum corneum hydration, sebum content, transepidermal water loss rates, skin blood perfusion and current perception threshold before and after using spray. Facial images were captured by VISIA-CR, and the image analysis program (Image‐Pro Plus) was used to analyze these to obtain the redness value of the facial skin. Moreover, lactic acid sting test scores and participants’ self-assessments were also performed at baseline, week 2 and week 4. Both sprays A and B significantly decreased the lactic acid sting test score, transepidermal water loss rates, skin blood perfusion, and redness, while increasing the stratum corneum hydration. Compared to spray B, spray A increased sensory nerve thresholds at 5 Hz and decreased the transepidermal water loss rates, skin blood perfusion, and lactic acid sting test score. Sprays containing birch juice improved cutaneous biophysical properties in participants with sensitive skin.
... The reason why almost 90% of the infants with the Koch-like phenomenon with IGRA tests results available were IGRA negative is that they may have been infected with NTM, such as M. marinum [17] and M. avium, [18] as some authors previously reported, rather than M. tuberculosis. The reason why the number of Koch-like phenomenon reports increased in winter is that skin reactivity in general increases in dry and cold weather conditions in winter in Japan; [26][27][28][29] however, other mechanisms may need to be explored. ...
Background:
The epidemiology of infants who exhibited the Koch-like phenomenon after Bacillus Calmette-Guérin vaccination and who subsequently tested positive in interferon-γ release assay (IGRA) was compared to that of those who tested negative. The reports of pediatricians on the phenomenon to the health authorities of Japan were retrieved and analyzed.
Methods:
In 2013-2019, 790 infants with such events were reported with IGRA test results available, of whom 81 (10.3%) tested positive and 709 (89.7%) negative.
Results:
The infants who were IGRA positive did not show an increasing trend (P = 0.06, P = 0.60), whereas those who were IGRA negative showed a significantly increasing trend (P = 0.42, P = 0.0002). The infants who were IGRA positive did not exhibit seasonality, whereas those who were IGRA negative had a higher number of cases in winter than in summer. The rates of infants who were IGRA positive per 10 million live births showed a significant correlation with the tuberculosis (TB) notification rates by prefecture (P = 0.41, P = 0.004), whereas those who were IGRA negative did not (P = 0.04, P = 0.78).
Conclusion:
The IGRA-positive infants were distributed quite differently from those who were IGRA negative and appeared more likely to be infected with TB. Reports of pediatricians on the Koch-like phenomenon should continuously be collected as the reports reflect a risk of TB infection including TB outbreaks among infants in Japan. The reports should include IGRA test results as IGRA is more specific than tuberculin skin testing. Infants with IGRA-positive results should be followed up for 2-3 years to determine their final outcomes.
... 7 A recent review of the literature indicated that low humidity and low temperatures lead to a general decrease in skin barrier function and to increased susceptibility towards mechanical stress. 55 These findings remain in line with the clinical observations of winter xerosis and of skin dryness in the elderly. Moreover, cold and dry weather are known to increase the prevalence and risk of flares in patients with atopic dermatitis. ...
... Aggravating factors, low temperatures, and an arid climate in northern China may have negative effects on the skin that may aggravate pruritus in patients. 18 Regional specific plants and flowers are also important components of environmental allergens. South China belongs to the subtropical and tropical regions, with subtropical grass pollens being more abundant. ...
Background: Atopic dermatitis (AD) is one of the most prevalent chronic inflammatory skin disorders that causes great disease burdens world-wide. The demographics and clinical characteristics of AD are different between countries, regions, and age groups yet these differences were not well characterized in China. To get well guidance for AD clinicians, we described the demographics, clinical characteristics, comorbidities, patient-identified aggravating factors and treatment of AD in all-age patients in China. Methods: This study included Chinese individuals diagnosed with AD by accredited clinicians in the department of dermatology of 205 hospitals from 31/34 provincial administrative divisions across China during August, 2021 to September, 2022. All included patients completed dermatologist-lead interviews regarding their general medical history, comorbidities, AD-related aggravating factors and medications. Two-level mixed ordered logistic regression was used to evaluate factors for aggravation of the disease. Results: Overall, 16838 respondents were included in the final analysis with a mean age of 30.94 years (standard deviation, ± 24.08 years). The proportion of patients with severe AD was the highest in patients with onset of AD at ≥60 years old (26.73%). Allergic rhinitis and hypertension were the most common atopic and non-atopic comorbidities, respectively. AD severity was significantly associated with chronic urticaria, food allergy and diabetes. There was a high proportion of severe AD in patients who had aggravating factors such as seafood, lamb and beef, chili peppers, alcohol, seasonal changes, and psychological factors. Cross-sectional survey revealed unmet needs of severe AD in treatment strategy, in lack of immunosuppressants’ and biological agents’ application. Conclusion: Treatment of comorbidities and control of aggravating factors significantly contribute to AD management. Improving systemic immunotherapy could reduce the incidence of severe AD.
... Interestingly, some recent articles suggest a relationship between climatologic factors and AD. Low temperature and low humidity may lead to skin barrier dysfunction and increase the risk of dermatitis (44); however, the relationship between immune responses, temperature, and skin diseases remains unknown. Investigations of the local temperature in AD lesions will be pursued in future work. ...
The pathology of skin immune diseases such as atopic dermatitis is closely related to the overproduction of cytokines by macrophages. Although the pathological functions of macrophages in skin are known, mechanisms of how they detect the tissue environment remain unknown. TRPV4, a nonselective cation channel with high Ca2+ permeability, is activated at physiological temperatures from 27 to 35°C and involved in the functional control of macrophages. However, the relationship between TRPV4 function in macrophages and skin immune disease is unclear. In this study, we demonstrate that TRPV4 activation inhibits NF-κB signaling, resulting in the suppression of IL-1β production in both human primary monocytes and macrophages derived from human primary monocytes. A TRPV4 activator also inhibited the differentiation of human primary monocytes into GM-CSF M1 macrophages but not M-CSF M2 macrophages. We also observed a significant increase in the number of inducible NO synthase–positive/TRPV4-negative dermal macrophages in atopic dermatitis compared with healthy human skin specimens. Our findings provide insight into the physiological relevance of TRPV4 to the regulation of macrophages during homeostasis maintenance and raise the potential for TRPV4 to be an anti-inflammatory target.
... It is noted, our study showed that the population with a history of allergic dermatologic diseases including urticaria, AD and ACD, was at increased risk for CC occurrence. Likewise, previous studies demonstrated that dryness was correlated well with the severity of AD and ACD 12,13 as a result of significant decrease in the skin barrier function 14 , which further highlight the close relationship between CC and allergic dermatologic disease. In agreement with this, a recent cross-sectional study which examined the multiple factors involved in the aetiology of CC showed that of the systemic diseases recorded among CC patients, skin diseases were noticed most frequently although the type of skin disease was not described in detail 15 . ...
Chronic cheilitis (CC) is a spectrum of inflammatory changes of unknown etiology that affect the vermilion of the lips. This study aimed to describe the epidemiology, clinical presentations and risk factors of CC. Patients with CC were recruited from the National Clinical Research Center for Oral Disease of China. A convenience sample of inhabitants who live in the same geographical region were recruited as the control group. The lip skin transepidermal water loss (TEWL) and capacitance of CC patients were compared with that of age- and gender-matched controls. Our results demonstrated that of the 109 patients with CC, 72 (66.1%; 95% CI: 57.0–75.1%) were female. The common clinical presentations of CC consisted of desquamation (n = 99; 90.8%), and/or chapping (n = 81; 74.3%), and/or pruritus (n = 64; 58.7%). Multivariable analysis showed that allergic dermatologic diseases ( P < 0.001; OR: 4.5; 95% CI: 2.4–8.4), anemia ( P = 0.001; OR: 3.3; 95% CI: 1.5–7.5), and indoor/outdoor alternate working environment ( P < 0.001; OR: 2.1; 95% CI: 1.5–2.8) were the significant risk factors for CC. The mean lip skin TEWL was found to be significantly higher, while the capacitance was lower in CC patients compared to that of control individuals. This study provides insights into the etiopathogenesis of CC and may help clinicians to identify the most effective management strategies.
... Contrary to these findings, Miyake et al. showed no relationship between atopic eczema and having a carpet in the child's room [28]. Furthermore, human skin is susceptible to mechanical stress after being exposed to a dry environment [29,30]. The second most common risk factor was using an air conditioner at home. ...
Background Eczema is a common inflammatory skin disorder in the pediatric population. Although eczema is a significant public health issue with negative impacts on quality of life, studies looking at the prevalence and risk factors among preschool-aged children in Saudi Arabia are limited. Methods A descriptive, cross-sectional, online-based study was conducted among parents of preschool children in Hail City, Saudi Arabia, between July 2022 and September 2022. The self-administered, pre-tested questionnaire was distributed on social media networks for data gathering, which was subsequently analyzed using Statistical Package for the Social Sciences (SPSS, IBM Corp., Armonk, NY) software. Results Among 964 preschool children, 54.5% of the children have been diagnosed with eczema. A total of 152 (60.1%) male children had eczema compared to 231 (59.8%) female children, while 142 (43.7%) parents had children of both genders diagnosed with eczema (P = 0.001). Multivariate logistic regression showed that male gender (odds ratio [OR] = 1.41, 95% confidence interval = 1.16-1.71), smoking in the house (OR = 1.85, 95%CI = 1.37-2.50), presence of mold or dampness in the house while the mother was pregnant (OR = 1.95, 95%CI = 1.17-3.24), house renovation during the mother's pregnancy (OR = 1.54, 95%CI = 1.01-2.34), use of an air conditioner (OR = 1.57, 95%CI = 1.07-2.30), and dry skin (OR = 5.83, 95%CI = 4.27-7.96) were significant predictors for the development of eczema. Conclusion The high prevalence of eczema among preschool-aged children in Hail indicates the need for parents to take action at the household level and beyond to successfully lower the risk of eczema development in the region.
... Le lien entre débit sanguin et température de la peau est cohérent avec des résultats précédemment observés [264]. Il a aussi précédemment été observé que lorsque la température ambiante augmente, la peau tend à s'assouplir notamment en raison d'une sécrétion de sébum accrue [265]. Enfin, la variation de température moyenne ainsi que le flux sanguin micro cutané initial sont tous les deux corrélés à l'épaisseur de l'hypoderme ce qui est en accord avec les résultats de Leblanc [266]. ...
L’utilisation de dispositifs médicaux en textile est très courante pour le traitement de troubles articulaires ou pour les problèmes d’insuffisance veineuse. Le principe actif de ces traitements réside dans l'application d'une contrainte mécanique à la surface du membre à soigner. Le fonctionnement physiologique du corps est alors modifié afin de s’adapter au nouvel équilibre imposé par le dispositif. Cependant, même lorsqu’il est convenablement dosé, le traitement de compression est souvent inconfortable pour les patients. Cela se traduit fréquemment par un abandon du traitement en raison d'une intolérance cutanée ou d'une intolérance à la pression. On peut raisonnablement supposer que ces irritations cutanées sont liées à l'état mécanique imposé à la peau par le dispositif de compression.L’objectif de cette thèse est d’étudier les interactions entre le textile médical et la peau afin de mieux comprendre les conditions mécaniques favorisant l’apparition d’intolérances cutanées chez les personnes qui utilisent ce type de dispositifs. Le développement d'une nouvelle méthode expérimentale a d'abord permis d'effectuer des mesures des déformations subies par la peau lors de différentes interactions de contact. Une étude clinique pilote a ensuite permis d'identifier des facteurs biomécaniques déterminants dans le développement d’irritations cutanées lors de l’utilisation de bas médicaux de compression. Pour finir, l’effet sur l'état mécanique de la peau lors du frottement des propriétés morphologiques et mécaniques de la peau, identifiés cliniquement comme des facteurs de risque pour l'irritation mécanique de la peau, a été étudié au travers d'un plan d'expériences numériques.
... This is also consistent with the early reports of enhanced barrier quality under low-humidity conditions. 8,34 In summary, the results of this clinical study demonstrated that daily and prolonged usage of face masks, which is an essential personal and public health practice during the COVID-19 pandemic, 35 can create a high-humidity microenvironment, which may negatively impact skin properties, including increased sebum production, reduced skin hydration, and weakened SC barrier integrity. However, facial moisturizer with high water binding ingredients and less occlusive emollients can alleviate these issues and help maintaining epidermal ...
Background:
Prolonged face mask usage, a daily practice for the public due to the COVID-19 pandemic, creates high levels of humidity underneath the mask, which may cause unexpected skin concerns.
Objective:
To investigate the impact of repeated mask usage on the face by comparing skin properties inside and outside of the mask-covered areas.
Methods:
A double-blinded, randomized, split-face clinical study was conducted with 21 healthy female participants who wore face masks at least 6 h every day for 1 week, with one side of their face treated with a moisturizer three times daily. On day 8, after 5 h of wearing the mask, skin properties (sebum, hydration, and trans-epidermal water loss [TEWL]) were evaluated at 15, 60, and 120 min post-mask removal, followed by barrier disruption and recovery assessment.
Results:
Mask usage weakened stratum corneum (SC) on facial skin compared to uncovered areas, including reduced SC hydration (p < 0.02 at 15 min) and increased TEWL in response to tape stripping challenge (p < 0.03 after stripping). In addition, sebum production also increased after mask removal (p < 0.01 at 15 min). Notably, a daily moisturizer mitigated these effects by increasing SC hydration (p < 0.001) and improving SC resilience against barrier disruption.
Conclusion:
Daily prolonged usage of a facial mask, essential due to the COVID-19 situation, generated a high-humidity microenvironment and led to compromised SC, which was revealed by a barrier challenge technique. Moreover, proper facial moisturization may help to maintain skin homeostasis and prevent the barrier impairment caused by repeated mask usage.
... Wearing mask makes the positive effect of temperature on sebum production more apparent 58,59 . Engebretsen et al. reviewed the negative effect of low humidity, low temperatures and different seasons on the skin barrier, and concluded that low humidity and low temperatures lead to a general decrease in skin barrier function and increased susceptible towards mechanical stress 60 . Notably, we found that an increase in environmental relative humidity was accompanied by an increase in transcutaneous water loss. ...
Geographical, environmental and pollution conditions affect facial skin health, but their effects on skin appearance have not been elucidated. This study aimed to describe the skin barrier and skin tone characteristics of Chinese subjects according to lifestyle and environmental conditions using in vitro measurements. In total, 1092 women aged 22–42 years were recruited from 7 representative Chinese cities. Eight skin parameters (hydration, sebum, pH, transdermal water loss, individual type angle, melanin index, erythema index, yellowness) were measured using noninvasive instruments; individual lifestyle data were also collected. Data on four meteorological factors (air temperature, relative humidity, sunshine duration, wind speed) and seven air pollution indicators (air quality index, fine particulate matter, breathable particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide and ozone) were collected in each city from the China Meteorological Administration. Facial skin characteristics differed significantly between cities. Facial skin barrier characteristics and skin tones showed regional differences, with a better skin barrier associated with the western region, as indicated by high skin hydration and sebum secretion and a low pH value. According to the value of transdermal water loss, lighter and darker skin tones were found in the western and southern regions, respectively. Environmental conditions affected facial skin status. Air pollution induced facial skin issues, with fine particulate matter and nitrogen dioxide contributing the most. Individual lifestyles affected the facial skin barrier and skin tone.
... Skin barrier dysfunction in AD pathogenesis is closely associated with environmental factors. A temperate climate with low temperature and low humidity hinders skin barrier function, which promotes inflammatory responses in the skin, and increases the risk of AD flare [29][30][31]. In addition, skin barrier dysfunction allows easy infiltration of allergens and pathogenic microbes into the skin, which leads to exacerbation of AD [2,32]. ...
To overcome interruption of skin barrier in transdermal drug delivery, the microneedle (MN) patch penetrates the barrier by punching with its MNs. Setting a needleless patch (NL patch) as the control intervention, this study assessed the efficacy of a biodegradable hyaluronic acid MN patch (BHMN patch) for atopic dermatitis (AD) patients with dry skin. Similar two AD lesions were selected from the extremities of a participant. For one lesion, a BHMN patch was attached for 6–8 h on where an aroma cream was applied (BHMN patch group). Simultaneously, an NL patch was attached on the other lesion as in the BHMN patch group (NL patch group). For 2 weeks, the interventions were conducted 3 times a week. The local scoring AD (L-SCORAD) index, the visual analog scale for pruritus and skin dryness, skin hydration, the transepidermal water loss (TEWL), and safety were assessed. Fifteen participants finished this trial with no dropouts. Both groups improved the L-SCORAD index after 2 weeks (p < 0.05), but the score of the BHMN patch group decreased more than that of the NL patch group (p < 0.05). The other outcomes, except for the TEWL, also showed statistical significance in intragroup comparisons. Nevertheless, none of the other outcomes showed statistical significance in intergroup comparisons. The TEWL showed no statistical significance even in intragroup comparison. Recoverable minor adverse events were reported in three cases. Considering the result of L-SCORAD index, the BHMN patch may be effective for ameliorating AD. However, a large-scale confirmatory trial is necessary to reassess other outcomes.
Trial Registration: This study was registered with the Clinical Research Information Service, Republic of Korea (Submitted date: 04/01/2022, Registered date: 23/02/2022, The first participant enrollment: 01/12/2021, Registration No. KCT0007037).
... A study on AD mouse models showed that the itching was aggravated in a warm environment (Seo et al. 2020), high temperatures activate the transient receptor potential vanilloid (TRPV) channel to generate pruritus symptoms (Andersen et al. 2017). Low temperature may cause impaired skin barrier function (Engebretsen et al. 2016). Halkier-Sørensen et al. (Halkier-Sørensen et al. 1995) used the hairless mouse model to demonstrate that cold exposure is not conducive to the recovery of the skin barrier. ...
Atopic dermatitis (AD) is one of the leading burdens of skin disease in children globally. Meteorological factors are involved in the onset and development of AD. Several studies have examined the effects of meteorological factors on AD, but their results are inconsistent, and the understanding of the link between AD and meteorological factors remains inadequate. In this study, a total of 19,702 children aged 0 to 14 visited the outpatient clinic for AD from 2015 to 2019 in Lanzhou, China. A distributed lag nonlinear model (DLNM) applies to evaluate effects of meteorological factors on childhood AD in Lanzhou, China, and further explored age and gender differences. It was found that extremely high or low temperatures, extremely high diurnal temperature range (DTR), extremely low relative humidity (RH), and extremely high wind speed (WS) increased the risk of outpatient visits for childhood AD. Effects of extremely high DTR and extremely high WS were more intense, with maximum cumulative risks of 2.248 (95% CI 1.798, 2.811) and 3.834 (95% CI 3.086, 4.759) at lag 0–21, respectively. Furthermore, the combination of low temperature and low RH can also contribute to the higher risk of childhood AD. For extreme temperatures, children aged 7–14 years were more vulnerable. For extremely low RH, extremely high DTR and WS, boys and children aged 0–3 years were more vulnerable. Public health departments should strengthen publicity and education about how meteorological factors affect childhood AD and develop sex- and age-specific preventative measures.
... Vários estudos demonstram que a elasticidade da pele aumenta conforme a temperatura. (Engebretsen, et al., 2015). ...
A COVID-19 afetou mais de 250 milhões de indivíduos e causou mais de cinco milhões de óbitos no mundo, sendo declarada como pandemia. Como transmissão ocorre entre pessoas, é essencial que os profissionais de saúde utilizem equipamentos de proteção individual para mitigar sua disseminação. Embora essenciais, seu uso prolongado leva a sérias manifestações cutâneas e redução de sua adesão. O objetivo deste estudo é resumir a prevalência das lesões cutâneas relacionadas ao uso de máscaras faciais; seus tipos e localização; fatores de riscos e medidas preventivas, no contexto da pandemia da COVID-19. Foi realizada uma revisão integrativa, utilizando as bases de dados MEDLINE, Scopus e EMBASE por meio de busca envolvendo descritores e termos-chave, da concepção até o dia 25 de janeiro de 2022. A pesquisa identificou 4276 artigos e 37 deles atenderam aos critérios de inclusão, sendo adicionados para análise, representando 14897 participantes. A prevalência de efeitos adversos foi de 42,23%. As lesões mais comuns encontradas foram prurido, eritema e acne. As regiões mais afetadas foram: ponte nasal, geniana, mentoniana e auricular posterior. Os principais fatores de risco foram o uso de N95, uso prolongado de máscaras e história prévia de dermatoses. Respiradores N95 e similares estiveram relacionados a maior taxa de efeitos adversos e alterações dos parâmetros fisiológicos. As medidas de prevenção tiveram efeito positivo nos estudos. Portanto, a taxa de lesões relacionadas ao uso de máscaras é alta, portanto, essas devem ser encaradas como problema de saúde pública para adoção de intervenções preventivas.
... However, the average decrease in TEWL was not signi cant before and after the treatment of CAP. The function of the skin barrier is affected by multiple extrinsic factors, such as temperature, humidity, and ultraviolet irradiation [24,25] . Recent studies have also revealed that the function of the skin barrier is associated with patients' stress [26] . ...
Introduction: Cold atmospheric plasma generates free radicals through the ionization of air at room temperature. Its effect and safety profile in patients with atopic dermatitis have not been evaluated prospectively.
Objective: We aimed to investigate the effect and safety of cold atmospheric plasma in patients with atopic dermatitis with a prospective pilot study.
Methods: Cold atmospheric plasma treatment or sham control treatment were applied respectively in randomly assigned and symmetric skin lesions. Three treatment sessions were performed at weeks 0, 1, and 2. Clinical severity indices were assessed at weeks 0, 1, 2, and 4 after treatment. Additionally, the microbial characteristics of the lesions before and after treatments were analyzed.
Results: We included 22 patients with mild to moderate atopic dermatitis presented with symmetric lesions. We found that cold atmospheric plasma can alleviate the clinical severity of atopic dermatitis. Modified atopic dermatitis antecubital severity and eczema area and severity index score were significantly decreased in the treated group. Furthermore, scoring of atopic dermatitis score and pruritic visual analog scales significantly improved. In microbiome analysis revealed significantly reduced proportion of Staphylococcus aureus in the treated group.
Conclusion: Cold atmospheric plasma can significantly improve mild and moderate atopic dermatitis without safety issues.
... Interestingly, low temperatures and humidity have also been associated with AD prevalence and flares in temperate countries. (166) This may explain why a subset of patients develop flares during the cool and dry season, between December to May. Physicians caring for patients with AD may counsel patients and parents to avoid extremes in temperature as much as possible and advise the use of lightweight fabrics. ...
Consensus statement on the treatment of Atopic Dermatitis among adult and pediatric dermatologist in the Philippines
... Meteorological events, both seasonal and daily, can affect both geographical regions and the well-being of populations [4]. Previous studies have demonstrated that weather is associated with short-term mood changes, emotional well-being and behavior changes, and various health conditions: pneumonia, bronchitis, cardiovascular and infectious diseases, stroke, atopic diseases, vitamin D deficiency, changes in sperm count and birth rates, and other morbidity effects [4][5][6][7]. In addition, investigations of weather changes on pregnancy outcomes have examined risks of low birth weight (LBW), preterm birth, gestational diabetes mellitus, preeclampsia, congenital malformations, abortion, and stillbirth [8]. ...
Background To estimate a possible association between the effects of daily meteorological variation and climatological changes (temperature, air pressure, humidity, sunniness level) on pregnant women with hyperemesis gravidarum (HG) according to symptoms grade and hospitalization state.
Methods A retrospective study was conducted with 118 patients diagnosed and hospitalized with HG. HG patients were graded as mild, moderate, or severe according to the Pregnancy Unique Quantification of Emesis (PUQE-24) scale. Data regarding demographic characteristics, PUQE scale value, gestational week on hospitalization, hospital admission and discharge dates, weather conditions, daily meteorological values during hospitalization ( temperature, air pressure, humidity, sunniness level), seasonal averages, and daily changes were recorded. Weather records were obtained from the Ankara Meteorology General Directorate (Ankara, Turkey). Differences between groups were compared according to HG grade.
Results HG cases were classified as mild (33.1%), moderate (44.9%), or severe (22.0%). The number of hospitalization days significantly differed between these three groups (p<0.05). In contrast, no statistically significant differences were identified between the HG grade level groups in regard to humidity, pressure, temperature, and sunniness level data (p>0.05). In addition, no statistically significant relationship was identified between HG grades and seasonal conditions according to the chi-square test (p>0.05).
Conclusion Changes in the meteorological and climate values examined were independent of symptom severity and hospitalization rate for our HG patients. However, it is possible that climate changes occurring around the world may affect the pregnancy period and should be further investigated.
... Skin barrier function is negatively affected by climate, and there are clear seasonal differences in hydration of the skin, peaking during the summer and bottoming in the winter, causing winter xerosis [56][57][58]. Skin appearance can be influenced by controlling the hydration of the skin, and dry skin with alkaline pH has been linked to faster persistent wrinkling in an 8-year longitudinal study [49]. The amount of water accumulated in the outermost corneal layer is defined as skin hydration, which depends on natural hygroscopic agents in corneocytes, natural moisturizing factors, and intercellular lipids [1]. ...
The effects of orally consumed probiotics on skin wrinkles and dryness are not fully known. A randomized, placebo-controlled, triple-blinded study was conducted with 148 healthy Korean female volunteers aged between 33 and 60 years, who were administered 1.75 × 109 colony-forming units (CFUs) of Bifidobacterium animalis subsp. lactis Bl-04 (Bl-04) (N = 74) or matching placebo (N = 74) for 12 weeks. Facial wrinkles (with 3-dimensional (3D) imaging), skin hydration, transepidermal water loss (TEWL), elasticity, and gloss were assessed at baseline and after every 4 weeks of the intervention. Questionnaire-based subjective evaluations of product efficacy and usability were also analyzed. The consumption of Bl-04 was safe and ameliorated significantly facial skin wrinkle parameters (total wrinkle area and volume, average depth of wrinkles, and arithmetic average roughness (Ra)) versus placebo at 4 weeks, but there were no differences at Week 8 or 12 between groups. Skin hydration, TEWL, elasticity, and gloss were similar between treatment groups, as were the subjective evaluation scores. Oral consumption of Bl-04 indicated promising short-term effects on skin appearance from the winter toward the spring. In future study designs, special attention should be paid to environmental conditions as well as to the skin condition and age of the participants.
... Topicals are designed to exhibit locally acting effects with a limited amount of skin permeation. Often to gain U.S. Food and Drug Administration (FDA) product approval, the pharmacokinetic (PK) profile of the drug from the respective topical vehicle (e.g. a patch or gel) is tested; however, because these products remain unoccluded, several reports have provided evidence of altered permeation and drug release rates under external influences such as heat, humidity, and reapplication (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). The highly diverse conditions that the product user may be exposed to on a daily basis have the potential to increase the flux profile from a topically applied product above the intended absorption levels collected under optimal use. ...
Purpose
It is often unclear how complex topical product formulation factors influence the transport kinetics through skin tissue layers, because of multiple confounding attributes. Environmental factors such as temperature effect are also poorly understood. In vitro permeation testing (IVPT) is frequently used to evaluate drug absorption across skin, but the flux results from these studies are from a combination of mechanistic processes.
Method
Two different commercially available formulations of oxybenzone-containing sunscreen cream and continuous spray were evaluated by IVPT in human skin. Temperature influence between typical skin surface temperature (32°C) and an elevated 37°C was also assessed. Furthermore, a multiphysics-based simulation model was developed and utilized to compute the flux of modeled formulations.
Results
Drug transport kinetics differed significantly between the two drug products. Flux was greatly influenced by the environmental temperature. The multiphysical simulation results could reproduce the experimental observations. The computation further indicated that the drug diffusion coefficient plays a dominant role in drug transport kinetics, influenced by the water content which is also affected by temperature.
Conclusion
The in vitro testing and bottom-up simulation shed insight into the mechanism of dermal absorption kinetics from dissimilar topical products.
... Previous studies investigated latitude [16], humidity [21], or sunshine [22] as a risk or preventive factor for AD. Each climate condition changes along with other climate conditions. ...
Objective
To determine the climate conditions that affect the incidence of atopic dermatitis from infancy to 3 years old.
Study design
We analyzed 100,303 children born from 2011 to 2014 for follow-up until 3 years old using cohort data from the Japan Environment and Children’s Study. The study included 15 Regional Centers, including 19 prefectures across Japan. We used meteorological data of the Japan Meteorological Agency. We calculated the hazard ratio (HR) of the standard deviation and low vs. high mean values of several climate conditions in children in their first 6 months of life to determine the incidence of atopic dermatitis.
Results
The Kaplan–Meier curve showed that children born in the months of October to December had the highest incidence of atopic dermatitis. Among climate conditions, a one standard deviation increase in the temperature (HR = 0.87), minimum temperature (HR = 0.87), and vapor pressure (HR = 0.87) showed the lowest HRs for the incidence of atopic dermatitis. These results were confirmed by an analysis by strata of the birth season. A low vapor pressure (HR = 1.26, p<0.0001) and the combination of a low mean temperature or low mean minimum temperature and low vapor pressure (HR = 1.26, p<0.0001) were associated with the highest incidence of atopic dermatitis. These results were consistent when they were adjusted for a maternal and paternal history of allergy and the prefecture of birth.
Conclusion
Among climate conditions, a low vapor pressure is the most strongly associated with a high incidence of atopic dermatitis. Measuring vapor pressure may be useful for preventing atopic dermatitis.
... Dermatitis is a frequent condition in temperate countries during harsh winter months due to the disruption of skin barrier function caused by low temperature coupled with low humidity. [8] In addition, Araya et al. have shown that, in warm and moist climates, the summer season may also Winter cause an increase in SD cases due to conditions favoring fungal propagation in the skin (e.g., high humidity). [9] The effects of climate are not limited to temperature and humidity, but also include sunlight exposure. ...
S eborrheic dermatitis (SD), also called seborrheic eczema, is a chronic skin condition seen in all ages which causes patches of scaly, flaking lesions localized on the scalp, face, and oily regions of the body. [1] Dandruff is a characteristic outcome of SD of the scalp and may be the only symptom when SD is minimal and limited to this region. [2] SD is usually identified as a red scaly rash covering the sebaceous regions of the forehead, scalp, upper chest, and back; but the appearance can differ, particularly in infants (cradle cap) and with respect to individual skin properties. [2] Although severe SD frequency is relatively low, SD and dandruff are estimated to affect half of the adult population; [3] however, its etiology is not well described. [1] In addition to patient-related features, such as age and Objectives: The aim of this study was to determine the frequency of seborrheic dermatitis (SD) by months and seasons in Istanbul, Turkey, and to examine the relationships between SD frequency and meteorological data, such as average temperature (°C), average humidity (%), average sunshine duration, and solar radiation per months. Methods: The study was conducted at Dermatology Department of Haseki Training and Research Hospital. The data of all adult patients who applied to the dermatology outpatient clinic between June 2018 and May 2020 were obtained. Monthly average climate data values of Istanbul between the same period were requested from the Turkish Ministry of Agriculture and Forestry, General Directorate of Meteorology. Results: During the study period, SD was diagnosed in 5316 patients (5.9% of the outpatient clinic). Among these, 2721 (51.2%) were male, 2595 (48.8%) were female, and mean age was 35.9±15.1 years-old. With respect to monthly distributions, SD frequency was 7.3% in December, 7.1% in February, 6.7% in November, and 6.6% in January; whereas June (3.8%) and July (3.9%) represented the lowest proportion of patients. Frequency of SD was similar in the autumn and winter seasons, despite considerable difference in average temperature. The frequency of SD was found to be strongly and inversely correlated with temperature values (r=-0,646, p<0.001) and monthly maximum humidity value (r=-0.609, p=0.001), while it was also moderately correlated with solar radiation levels (r=-0.442, p=0.027). Minimum or average humidity values and sunshine durations (daily and monthly) were not associated with frequency of SD. Spearman's Rho correlation was calculated to assess the directional relationships between continuous variables. Conclusion: Our study shows that environmental factors such as low temperature, low ultraviolet index, and low humidity are critical factors that increase the likelihood of SD development. These data support previous studies in terms of indicating that SD frequency might be increased in climate conditions favoring the growth of Malassezia species.
... Moreover, environmental factors such as temperature or relative ☆ This paper has been recommended for acceptance by Da Chen. humidity may alter the response to pollutants (Engebretsen et al., 2016). Several disorders that affect multiple organs are associated with environmental pollution (Schraufnagel et al., 2019a,b) and the main ones are: the nervous system in the case of Alzheimer's disease (Babadjouni et al., 2017;Block et al., 2012;Costa et al., 2020;Croze and Zimmer, 2018;Huat et al., 2019;Thomson, 2019;Zhi et al., 2017); the cardiovascular system for cardiovascular diseases (DiGiacomo et al., 2018;Bourdrel et al., 2017); the respiratory system for allergic or non-allergic respiratory diseases (Cecchi et al., 2018;Losacco and Perillo, 2018;Simon, 2019;Ye et al., 2017;Zhang et al., 2019); the reproductive system for fertility impairment (Carré et al., 2017;Tomza-Marciniak et al., 2018); embryonic development for stem cells (Ghosh and Ansar, 2014); skin for atopic dermatitis, eczema, and acneiform rash Ngoc et al., 2017;Simon, 2019). ...
Whatever the exposure route, chemical, physical and biological pollutants modify the whole organism response, leading to nerve, cardiac, respiratory, reproductive, and skin system pathologies. Skin acts as a barrier for preventing pollutant modifications. This review aims to present the available scientific models, which help investigate the impact of pollution on the skin. The research question was “Which experimental models illustrate the impact of pollution on the skin in humans?” The review covered a period of 10 years following a PECO statement on in vitro, ex vivo, in vivo and in silico models. Of 582 retrieved articles, 118 articles were eligible. In oral and inhalation routes, dermal exposure had an important impact at both local and systemic levels. Healthy skin models included primary cells, cell lines, co-cultures, reconstructed human epidermis, and skin explants. In silico models estimated skin exposure and permeability. All pollutants affected the skin by altering elasticity, thickness, the structure of epidermal barrier strength, and dermal extracellular integrity. Some specific models concerned wound healing or the skin aging process. Underlying mechanisms were an exacerbated inflammatory skin reaction with the modulation of several cytokines and oxidative stress responses, ending with apoptosis. Pathological skin models revealed the consequences of environmental pollutants on psoriasis, atopic dermatitis, and tumour development. Finally, scientific models were used for evaluating the safety and efficacy of potential skin formulations in preventing the skin aging process or skin irritation after repeated contact. The review gives an overview of scientific skin models used to assess the effects of pollutants. Chemical and physical pollutants were mainly represented while biological contaminants were little studied. In future developments, cell hypoxia and microbiota models may be considered as more representative of clinical situations. Models considering humidity and temperature variations may reflect the impact of these changes.
... In addition, the environmental factors in Indonesia, such as the higher temperature and humidity, may also contribute to the lower incidence of application site-related AEs. 33 Besides the low incidence of local ADRs, SFPP also demonstrated the low incidence of ADRs related to gastrointestinal disorders (1 constipation case only). Although systemic exposure in SFPP is higher than those in conventional topical NSAIDs due to the high percutaneous absorption, the transdermal patches, including SFPP, have no direct effect on gastric mucosal epithelial cells. ...
Aim:
S-flurbiprofen plaster (SFPP) is a novel topical nonsteroidal anti-inflammatory drug (NSAID) patch. This study aimed to assess the efficacy and safety of SFPP in knee osteoarthritis (OA) patients compared to diclofenac gel.
Methods:
This study was a multicenter, randomized, active-controlled, open-label, non-inferiority phase III trial. There were 311 enrolled patients treated by SFPP or diclofenac gel for 2 weeks. The primary efficacy outcome was the knee pain when rising from the specially arranged chair assessed by visual analog scale (rVAS). The other efficacy outcomes were clinical symptoms, pain on walking, global assessment by both investigator and patient, and use/non-use of the rescue drugs during the treatment period. Adverse events (AEs) were evaluated as the safety outcome.
Results:
The least-squares mean (95% CI) of ΔrVAS at the end of the study was 41.52 (39.16-43.88) mm in the SFPP group and 36.01 (33.69-38.33) mm in the diclofenac gel group, with a between-group difference of 5.51 (2.20-8.82), indicating non-inferiority. There were statistically significant differences between the groups in rVAS, clinical symptoms, pain on walking, and the global assessment by both investigator and patient. The incidence rate of AEs in the SFPP group was 5.8%, and there was no statistically significant difference from that in the diclofenac gel group (5.2%). Most of the AEs were mild, and no AE led to discontinuation.
Conclusion:
Non-inferiority of SFPP to diclofenac gel was demonstrated in the efficacy for pain on rising from a chair. SFPP was also well-tolerated in knee OA patients.
... Holidays in climate-friendly places should be recommended to every individual having AD. It has been suggested that permanently relocating to a different environment is advantageous (Engebretsen et al., 2016;Fieten et al. 2015). ...
Atopic dermatitis is a chronic as well as widespread skin disease which has significant influence on the life attributes of affected people and their families. Systemic immunosuppressive drugs can be utilised for effective care of disease, although they are often prescribed for rigorous disruption or disease that is complicated to manage. Therefore, topical applications of corticosteroids are considered the primary pharmacologic therapies for atopic dermatitis, and research recommends that these medications might be helpful in preventing disease flare-ups. However, topical medicine administration to deeper layers of skin is challenging because of the skin anatomic barrier that restricts deeper drug permeation, and also due to barrier function abnormalities in atopic dermatitis skin, which might result in systemic drug absorption, provoking systemic consequences. Hence, effective management of atopic dermatitis needs new, effective, safe and targeted treatments. Therefore, nanotechnology-based topical therapeutics have attracted much interest nowadays because of their tendency to increase drug diffusion and bioavailability along with enormous drug targeting potential to affected cells, and, thereby, reducing the adverse effects of medications. In this review, we mention different symptoms of atopic dermatitis, and provide an overview of the different triggering factors causing atopic dermatitis, with emphasis on its epidemiology, pathophysiology, clinical features and diagnostic, and preventive measures. This review discusses existing therapeutics for treating atopic dermatitis, and the newer approaches as well as the current classical pharmacotherapy of atopic dermatitis against new nanoparticle skin delivery systems. This review has also briefly summarised the recent patents and clinical status of therapeutic modalities for atopic dermatitis.
... AD is a complex disease whose etiology has not yet been fully deciphered due to its heterogeneity resulting from patient age, ethnicity, and lifestyle factors [7][8][9]. Moreover, although a genetic predisposition is undeniable in AD pathogenesis, the relative contribution of (epi)genetic [10][11][12][13] versus environmental factors [14][15][16] remains unknown. Heterogeneity of AD due to genetic polymorphism extends beyond filaggrin (FLG) loss-of-function mutations, since patients with serine peptidase inhibitor Kazal-type 5 (SPINK5) mutations also exhibit a severe AD-like phenotype, as do other patients with inherited disorders [17,18]. ...
Atopic dermatitis (AD) is a chronic and relapsing inflammatory skin disease in which dry and itchy skin may develop into skin lesions. AD has a strong genetic component, as children from parents with AD have a twofold increased chance of developing the disease. Genetic risk loci and epigenetic modifications reported in AD mainly locate to genes involved in the immune response and epidermal barrier function. However, AD pathogenesis cannot be fully explained by (epi)genetic factors since environmental triggers such as stress, pollution, microbiota, climate, and allergens also play a crucial role. Alterations of the epidermal barrier in AD, observed at all stages of the disease and which precede the development of overt skin inflammation, manifest as: dry skin; epidermal ultrastructural abnormalities, notably anomalies of the lamellar body cargo system; and abnormal epidermal lipid composition, including shorter fatty acid moieties in several lipid classes, such as ceramides and free fatty acids. Thus, a compelling question is whether AD is primarily a lipid disorder evolving into a chronic inflammatory disease due to genetic susceptibility loci in immunogenic genes. In this review, we focus on lipid abnormalities observed in the epidermis and blood of AD patients and evaluate their primary role in eliciting an inflammatory response.
... A possible explanation for this might be that scabies mites die faster at higher temperatures [33]. Furthermore, the natural skin barrier is more susceptible to lesions due to low temperatures [34], which in turn leads to increased itching [35] and thus further increases the burden for those affected by scabies. In addition, it could also play a role that people spend more time together indoors in winter than in summer [36], so that the risk of scabies transmission is increased. ...
Purpose
Scabies is a World Health Organization-defined neglected tropical disease and a growing public health issue worldwide. It is difficult to obtain reliable data on prevalence due to the lack of standardized tests. The aim of this study was to assess scabies online search behavior in Germany to identify local differences using Google search volume.
Methods
Google Ads Keyword Planner was used to investigate the scabies-related search volume for Germany as a whole, its 16 federal states, and 15 large cities for the period from January 2016 to December 2019. The identified search terms were qualitatively categorized and critically analyzed.
Results
A total of 572 keywords with an overall search volume of 11,414,180 searches regarding scabies were identified in Germany. The number of searches was higher in winter than in summer, with a national peak in March 2018. Around 30.6% of the searches regarding scabies therapy ( n = 978,420) were related to home remedies. Regarding body localization, most searches focused on the whole body ( n = 109,050), followed by head ( n = 89,360) and the genital area ( n = 28,640).
Conclusions
The analysis of Google search data provides an overview of the populations’ interest regarding scabies. The analysis can detect local peaks and assess the relevance of scabies at individual localizations of the body. The study highlighted current possible shortcomings in the therapy of scabies. It also underlined the importance of improving awareness regarding scabies so that affected individuals can consult a doctor earlier for treatment.
Cell swelling as a result of hypotonic stress is counteracted in mammalian cells by a process called regulatory volume decrease (RVD). We have recently discovered that RVD of human keratinocytes requires the LRRC8 volume-regulated anion channel (VRAC) and that Ca2+ exerts a modulatory function on RVD. However, the ion channel that is responsible for Ca2+ influx remains unknown. We investigated in this study whether the Ca2+-permeable TRPV4 ion channel, which functions as cell volume sensor in many cell types, may be involved in cell volume regulation during hypotonic stress response of human keratinocytes. We interfered with TRPV4 function in two human keratinocyte cell lines (HaCaT and NHEK-E6/E7) by using two TRPV4-specific inhibitors (RN1734 and GSK2193874), and by creating a CRISPR/Cas9-mediated genetic TRPV4-/- knockout in HaCaT cells. We employed electrophysiological patch clamp analysis, fluorescence-based Ca2+ imaging and cell volume measurements to determine the functional importance of TRPV4. We could show that both hypotonic stress and direct activation of TRPV4 by the specific agonist GSK1016790A triggered intracellular Ca2+ response. Strikingly, the Ca2+ increase upon hypotonic stress was neither affected by genetic knockout of TRPV4 in HaCaT cells nor by pharmacological inhibition of TRPV4 in both keratinocyte cell lines. Accordingly, hypotonicity-induced cell swelling, downstream activation of VRAC currents as well as subsequent RVD were unaffected both in TRPV4 inhibitor-treated keratinocytes and in HaCaT-TRPV4-/- cells. In summary, our study shows that keratinocytes do not require TRPV4 for coping with hypotonic stress, which implies the involvement of other, yet unidentified Ca2+ channels.
The prevalent form of ichthyosis in neutral lipid storage disease (NLSDI) is nonbullous congenital ichthyosiform erythroderma (CIE) characterized by fine, whitish scales on erythematous skin over the whole body. Here, we report a late-diagnosed, 25-year-old woman with NLSDI presenting with diffuse erythema and fine whitish scales throughout the body with patches of apparently normal skin, "islets of sparing" on her lower extremities. We observed that the size of the normal skin islets changed with time, and even the entire lower extremity was covered with erythema and desquamation like the rest of the body. Frozen section histopathological examinations were made from lesional skin and normal-looking skin; no difference was observed in terms of lipid accumulation. The only noticeable difference was the thickness of the keratin layer. In CIE patients, observation of patches of apparently normal skin or "islets of sparing" might be a clue for NLSDI to be distinguished from other CIE conditions.
According to recent data, the pathogenetically significant condition for the onset of atopic dermatitis is increasing epidermal permeability barrier and, therefore, a primary step in the treatment and prevention of atopic dermatitis should be control over the skin condition. Effective use of modern methods of prevention of exacerbations helps to reduce the frequency of relapses, lengthen the periods of remissions and, in general, improve the quality of life of sick children.
Background
The epidemiology of atopic dermatitis (AD) in Greenland has been sparsely investigated. This study examined the point -and overall prevalence, cumulative incidence at different ages, and associated risk factors for AD among children in Greenland.
Methods
Between 2019 and 2020 three towns in Greenland, representing 48% of the total population, were visited. A cross-sectional study was conducted, including children aged 0-7 years attending daycare centers. Parents completed a questionnaire with questions on AD and related risk factors. A diagnosis of AD was based on the U.K. Working Party’s (UKWP) criteria, along with a clinical examination.
Results
839 children aged 0-7 were included. The overall prevalence of AD was 35% according to physician’s diagnosis and assessment. The point prevalence was 28% and peaked among one-year-old children (36%) and declined with age. The cumulative incidence at ages 1-6 varied between 29-41% and was highest in one-year-old children and showed a slight decline with increasing age. In the fully adjusted multivariate model, AD was associated with being of Inuit descent (odds ratio (OR) 1.7 (95% confidence interval (CI) 1.1-2.8), food allergy in the child (OR 3.6 95% CI 2.3-5.6)), ear infection in the child (OR 1.4 95% CI 1.0-1.9)) having a mother with high educational level (OR 1.5 (95% CI 1.0-2.3)), maternal atopy (OR 1.4 (95% CI 1.1-2.0)) and paternal atopy (OR 2.0 (95% CI 1.5-2.8)). No environmental risk factors were identified.
Conclusion
The overall prevalence of AD in children in Greenland is high and has likely increased over the past 20 years. The point prevalence was highest in the youngest children indicating early onset of disease. Inuit descent, family atopy predisposition, and belonging to a high socioeconomic class increased the risk of AD. Insight in possible Inuit specific genetic predisposition is needed.
The purpose of this study was to clarify the physiological and subjective responses of the elderly to dehumidification in a humid summer and humidification in a dry winter compared with the young. Sixteen elderly and sixteen young subjects participated in the dehumidification experiment (DE) and 13 elderly and 15 young subjects participated in the humidification experiment (HE). The air temperature in the climate chamber was set at 28 °C, and humidity was decreased from 70% relative humidity (RH) to 50% RH for 90 min in the DE. The air temperature was set at 25 °C, and the humidity was increased from 30% RH to 50% RH for 90 min in the HE. Skin temperature, body weight, transepidermal water loss (TEWL), skin hydration state, saccharin clearance time (SCT), and blinking frequency were measured during exposure; whereby we evaluated humidity sensation, thermal sensation, and thermal comfort.
Dehumidification caused a significant decrease in skin temperature in both age groups owing to greater insensible perspiration. Humidification significantly shortened the SCT in both age groups. TEWL increased significantly in the DE and decreased in the HE. For the physiological responses (skin temperature, skin physiology, SCT, and blinking frequency) to dehumidification and humidification, no distinct differences between the age groups were observed. However, subjective responses suggested that the elderly were less sensitive to humidity differences than the young in both the DE and HE.
Ngari Prefecture, Tibet, China, features its ultrahigh altitude above 4200 m, very little annual precipitation and extremely low relative humidity. Residents who have migrated to Tibet from the plains use indoor humidification to reduce the respiratory discomfort caused by prolonged exposure to dry indoor air. In this study, field investigations and analysis of residential indoor environments and humidification methods in Ngari Prefecture revealed that ninety‐eight percent of humidifier consumers in the prefecture used low‐cost ultrasonic humidifiers filled with indoor tap water. The results revealed that the arsenic (As) concentration of the tap water was 41.6 μg/L, over four times China's standards for drinking water quality (10 μg/L). The source As concentration in the air humidified by the tap water‐filled ultrasonic humidifier is (619.8 ± 59.1) (ng/m3·air), while no As was detected in the air humidified by the evaporative humidifier. For ultrasonic humidifier with tap water‐filled, the inhalation dose of a healthy adult was 45.4 ng/d. The minute ventilation volume of migrated residents who had been in Ngari for less than two years (12.5 ± 4.3 L/min) was greater than those of the long‐term residents (10.0 ± 4.5 L/min), which may exacerbate the short‐term inhalation exposure risk for migrated residents. To reduce the health risks associated with As exposure, evaporative humidifiers are recommended for households using domestic water. If ultrasonic humidifiers are used, the tap water must be purified with terminal filters.
In plastic surgery and cosmetic dermatology, photographic data are an invaluable element of research and clinical practice. Additionally, the use of before and after images is a standard documentation method for procedures, and these images are particularly useful in consultations for effective communication with the patient. An artificial intelligence (AI)-based approach has been proven to have significant results in medical dermatology, plastic surgery, and antiaging procedures in recent years, with applications ranging from skin cancer screening to 3D face reconstructions, the prediction of biological age and perceived age. The increasing use of AI and computer vision methods is due to their noninvasive nature and their potential to provide remote diagnostics. This is especially helpful in instances where traveling to a physical office is complicated, as we have experienced in recent years with the global coronavirus pandemic. However, one question remains: how should the results of AI-based analysis be presented to enable personalization? In this paper, the author investigates the benefit of using gender- and age-specific scales to present skin parameter scores calculated using AI-based systems when analyzing image data.
On‐skin humidity sensors can be used to measure the sweat rate on the human skin surface. However, it is challenging to realize a precise, long‐term skin humidity measurement. The main challenge is to develop an on‐skin humidity sensor that has gas permeability, high sensitivity, and flexibility simultaneously. Porous materials and electrodes can enhance the properties of the humidity sensor for fulfilling continuous monitoring. Herein, a humidity sensor composed of nanomesh Au electrodes and nanomesh humidity‐sensitive materials, is reported. The porous structure makes the sensor flexible and gas permeable, increases the surface area, and leads to high sensitivity. The sensor has a high sensitivity of 640 000% in the relative‐humidity range of over 40–100%, together with a gas permeability similar to that of an open environment. The gas permeability suppresses the skin inflammation, endows natural evaporation of sweat, and brings an identical condition with bare skin. To evaluate the utility of the nanomesh sensor, on‐skin humidity measurements are performed, and the humidity change due to sweating after exercise is recorded. A nanomesh humidity sensor consisting of nanomesh Au electrodes and nanomesh humidity‐sensitive materials is proposed. The sensor achieves gas permeability, high sensitivity, and flexibility together to perform on‐skin measurements. The sensor has a sensitivity of over 640 000% in the relative humidity range of 40–100%. The humidity change due to sweating after exercise is recorded.
Previous studies investigating the associations between indoor air quality and health symptoms of schoolchildren have created a substantial knowledge; however, there are still inconsistencies and knowledge gaps. In the framework of the InAirQ study, the associations between the occurrence of recent health symptoms of children and the exposure to air pollutants in school buildings were investigated across Central Europe. Volatile organic compounds, aldehydes, PM2.5 mass, carbon dioxide and physical parameters (temperature, relative humidity) were measured during the heating period of 2017/2018 in 64 primary school buildings. A questionnaire was used to survey the prevalence of allergy and the occurrence of past-year asthma-like and recent (<3 months) respiratory, ocular, dermal and general symptoms of the children in the monitored classroom. In total, 1084 parent-reported questionnaires were completed. Significant spatial differences were identified in the reported symptoms. While the highest frequencies of asthma-like symptoms were reported among the Slovenian schoolchildren, the highest occurrences of recent respiratory, dermal and general symptoms were found in Poland. Regarding the relationship between the frequencies of respiratory symptoms and the concentrations of air pollutants, the following significant associations were identified: nasal obstruction and ethylbenzene, xylenes, formaldehyde, PM2.5 mass; sore throat and formaldehyde, acetaldehyde, propionaldehyde, hexanal, carbon dioxide, air stuffiness; irritative cough and PM2.5, hazard index. High concentrations of aromatic hydrocarbons were associated with the high occurrences of dermal symptoms. Significant associations were found between the frequencies of headache and fatigue and the levels of air stuffiness, while the occurrence of fatigue was also associated with hexanal concentrations.
As the outermost barrier tissue of the body, the skin harbors a large number of innate lymphoid cells (ILCs) that help maintain local homeostasis in the face of changing environments. How skin-resident ILCs are regulated and function in local homeostatic maintenance is poorly understood. We here report the discovery of a cold-sensing neuron-initiated pathway that activates skin group 2 ILCs (ILC2s) to help maintain thermal homeostasis. In stearoyl-CoA desaturase 1 (SCD1) knockout mice whose skin is defective in heat maintenance, chronic cold stress induced excessive activation of CCR10-CD81+ST2+ skin ILC2s and associated inflammation. Mechanistically, stimulation of the cold-sensing receptor TRPM8 expressed in sensory neurons of the skin led to increased production of IL-18, which, in turn, activated skin ILC2s to promote thermogenesis. Our findings reveal a neuroimmune link that regulates activation of skin ILC2s to support thermal homeostasis and promotes skin inflammation after hyperactivation.
The effect of ambient temperature on dermatologic diseases has received widespread attention. Previous studies have shown that ambient temperature might affect specific dermatologic diseases, but results were inconsistent. This study aims to assess the short-term effect of ambient temperature on outpatient visits due to dermatologic diseases (DMs) in Xinxiang, China. Daily DMs outpatient visits, mean temperature, mean relative humidity, and air pollution data of Xinxiang were retrieved from January 1, 2015, to December 31, 2018. A distributed lag nonlinear model (DLNM) was applied to analyze the effect of ambient temperature on DMs outpatients. We controlled several potential confounding factors such as the long-term trend, public holiday, day of the week, humidity, and air pollutants (NO2, PM2.5). Finally, two more stratification analysis was conducted by age and gender. A total of 164,270 outpatients of DMs were enrolled during our study, and the daily mean visits were 113. The estimated effect of temperature on DMs was nonlinear. Heat temperature would exacerbate outpatients of dermatologic diseases. With a reference median temperature (17 °C), the effect of temperature on DMs was most pronounced at lag0-14; exposure to heat (32 °C, 99th) was associated with 1.565 (95% CI: 1.266-1.934) increased risk of outpatients for DMs. Stratification analysis showed that citizens of young ages were susceptive to heat; both genders had a similar relationship between temperature and DMs risk. This study highlights that ambient temperature was associated with DMs outpatients; heat temperature might aggravate DMs risk. The health hazards of heat temperature required more attention, and more effective prevention measurements should be designed and implemented to curb global warming.
Background
Pressure injuries (PIs) are a well-known complication of critically ill patients admitted to the intensive care unit with targeted temperature management (TTM) after cardiac arrest (CA). However, little is known about the factors that impact the occurrence of PIs among these patients.
Objectives
This study aimed to examine factors related to the occurrence of PIs among patients after CA treated with TTM.
Methods
This retrospective observational study collected data from 126 patients after CA aged 18 years or older from a single tertiary hospital admitted between January 2017 and December 2019. Demographic, clinical, and medical device–related characteristics were collected by patient chart review. Multivariable logistic regression analysis was performed to identify factors related to the occurrence of PIs.
Results
The study showed that the incidence of PIs was 31.8%. Patients who were male (odds ratio [OR], 4.80; 95% confidence interval [CI], 1.21–19.08), developed diarrhoea (OR, 4.90, 95% CI, 1.31–18.41), or were subjected to physical restraint (OR, 6.03; 95% CI, 1.52–23.96) were at a higher risk of developing PIs. A lower risk of developing PIs was associated with the Glasgow Coma Scale score greater than 13 on the third day of admission (OR, 0.08; 95% CI, 0.01–0.52), higher haemoglobin level (OR, 0.65; 95% CI, 0.49–0.86), or low nutritional risk index (≤100) (OR, 0.10; 95% CI, 0.02–0.57).
Conclusions
Nurses should be aware that patients treated with TTM after CA are at a high risk of developing PIs from the moment of admission and should be closely monitored.
Background:
Stratum corneum is located in the outermost layer of the skin and is the most important part of the skin barrier. Stratum corneum mainly contains keratinocytes, lipids, and desmosomes. Their normal metabolic process is closely related to the function of skin barrier.
Aims:
This paper reviews the structure and function of stratum corneum, influencing factors, skin diseases, and common solutions.
Methods:
An extensive literature search was conducted on the structure and function of stratum corneum, influencing factors, skin diseases, and common solutions.
Results:
This paper reviews the structure and function of stratum corneum and the influence of various factors on stratum corneum metabolism. At the same time, the existing skin problems, skin diseases, and common solutions are summarized.
Conclusions:
This information will help to understand the function, molecular mechanism, and influencing factors of stratum corneum metabolism, and provide new ideas for stratum corneum health management and cosmetic research and development.
Conventional humidity sensors have poor flexibility and low sensitivity, which makes them difficult for wearable electronic device applications. This study aims to fabricate a flexible, high-sensitivity and breathable humidity sensor for skin humidity monitoring. The sensor includes two parts, i.e., shape memory polylactic acid fiber (SMPLAF) as the substrate and crumpled graphene oxide (CGO) membrane as the top humidity-sensitive layer. SMPLAF was firstly stretched and then heated to restore its original shape to obtain the CGO membrane. The unique crumpled morphology of CGO membrane provides a large specific surface area and high capillary force, which facilitates the rapid exchange of water molecules between the sensing CGO membrane and the external environment. Accordingly, the sensor exhibits excellent humidity sensitivity, fast response time (<5 s) and long term stability (15 days). Moreover, the CGO-based sensor demonstrates excellent flexibility. Bent at 120°, the response almost unchanged, whereas the response of the sensor without CGO decreased from 0.89 to 0.66. Though the sensor has the disadvantage of unstable performance at high RH, it could be overcome by controlling the wavelength of the crumpled structure of CGO. Due to the above superior properties, the sensor shows promising potentials for human breath monitoring and skin humidity test.
Type I keratin 9 encoded by the KRT9 gene serves an important special function either in the mature palmar and plantar skin tissue. The changes in skin conditions and thickening of the outer layer of the skin may be affected by environmental variables. A missense mutation rs209302038 (NC_037346.1: g.41782870 G > A) was detected in KRT9, which changing the isoleucine into valine. This study aimed to identify the frequency of allele in this locus in Chinese indigenous cattle, and analyze the connection with heat stress. Our results indicated that the frequency of allele A gradually decreases from south to north, while the frequency of G allele showed the opposite pattern. Further analysis of the association of the different genotypes with three climate factors, which showed that the genotypes (GG, GA, AA) were significantly related to climatic conditions (p < 0.01). Therefore, we speculated that the mutation of the rs209302038 in Chinese indigenous cattle might be a genetic marker to detect heat stress.
Background:
Previous studies have shown that serum 25-hydroxyvitamin D (25(OH)D) may be associated with atopic dermatitis (AD), and that vitamin D (VD) supplementation may decrease AD severity.
Objective:
The aim of this study was to investigate the association between serum 25(OH)D level and AD, and the effect of VD supplementation on AD severity, while providing stratified analyses based on latitude and region.
Methods:
A systematic review was performed on all published studies in MEDLINE, Embase, and Cochrane Library databases that analyzed effects of serum 25(OH)D and VD supplementation on AD.
Results:
This systematic review and meta-analysis includes 20 studies with 1882 cases of AD. We found significantly lower 25(OH)D levels in AD patients compared with healthy controls (HC) (p < 0.001), significantly lower 25(OH)D levels in severe AD compared with both mild and moderate AD (p < 0.001), and VD supplementation improved AD symptoms (p < 0.001).
Limitations:
Factors like seasonal and environmental changes, sunlight exposure, and cultural practices may confound the relationship between serum 25(OH)D and AD severity. There are limited randomized controlled trials that assess this association.
Conclusion:
Overall, lower serum 25(OH)D is associated with more severe AD, and VD supplementation may help lower AD severity. Further research is needed to confirm the presence and direction of causality of the relationship between VD and AD pathogenesis.
The pandemic of the 2019 novel coronavirus disease (COVID-19) has caused an unprecedented mobilization of the United States’ healthcare workforce. In addition to working extended hours under increased duress, healthcare professionals (HCP) of all stations have been making use of various types of personal protective equipment (PPE) with greatly increased frequency and duration. Current data regarding adverse skin reactions as a possible consequence of PPE use are, particularly in the United States, largely insufficient for policy-makers to make informed decisions regarding daily PPE use among HCP. The research vehicle employed by this study is a cross-sectional 25-item survey distributed via email to workers currently employed by a five-hospital system in southcentral Kentucky. This survey was used to collect information from hospital workers of all professional roles about their experiences during the COVID-19 pandemic, focusing on reports of adverse dermatological reactions and associated risk factors. Out of 879 respondents, 54.4% reported some type of skin irritation reaction. Skin irritation was significantly more prevalent among medical and medical support staff than non-medical hospital workers, with the highest prevalence among Certified Nurse Assistant (CNAs). Among clinical workers, those in dedicated COVID-19 units reported the highest prevalence of adverse skin reaction. The most common complaint was dryness/scaling of the skin (306 out of 439, 69.7%), and the most common location was the facial cheeks (305 out of 516, 59.1%). Among those who reported skin irritation, the average self-reported severity of skin reaction (on a scale of 1–5) was 2.00 ± 0.05, and the mean total days of skin reaction per month was 11.70 ± 0.39 days. Total days of irritation per month was found to be significantly related to “total days of PPE use per month,” “hours of PPE use per day,” “frequency of hand washing,” and “use of disinfecting UV irradiation.” Severity of skin reaction was found to be significantly related to “hours per day of PPE use,” “consecutive days of PPE use,” and “female sex.” Clinical workers that put in the most face-to-face time with patients, and those in dedicated COVID-19 units, had the highest risk of adverse skin reaction. Overall, skin reactions were found to be mild, even in those hospital workers with the heaviest PPE use. Because the widespread and consistent use of facial masks in public settings has become a key tool in our protracted struggle with SARS-CoV-2, these findings may help to ameliorate concerns that everyday facial mask and/or other PPE usage contributes to significant dermatologic morbidity among both medical professionals and public citizens.
Background:
Children born in the fall and winter are at increased risk for developing atopic dermatitis and food allergy. Because these seasons are associated with low temperatures, we hypothesized that exposure to low temperatures may compromise keratinocyte differentiation and contribute to skin barrier dysfunction.
Objective:
We examined whether low temperature causes skin barrier dysfunction.
Methods:
Primary human epidermal keratinocytes (HEK) were differentiated in 1.3 mmol CaCl2 media and cultured at different temperatures. The cells were transfected with transient receptor potential cation channel subfamily V member 1 (TRPV1) or STAT3 small interfering RNA (siRNA) to examine the effects of these gene targets in HEK exposed to low temperature. Gene expression of TRPV1, epidermal barrier proteins, and keratinocyte-derived cytokines were evaluated. Organotypic skin equivalents were generated using HEK transfected with control or TRPV1 siRNA and grown at 25°C or 37°C. Transepidermal water loss (TEWL) and levels of epidermal barrier proteins were evaluated.
Results:
Filaggrin (FLG) and loricrin (LOR) expression, but not keratin (KRT)-1 and KRT-10 expression, was downregulated in HEK incubated at 25°C, while TRPV1 silencing increased intracellular Ca2+ influx (keratinocyte differentiation signal) and enhanced the expression of epidermal differentiation proteins. IL-1β and thymic stromal lymphopoietin induced by low temperature inhibited FLG expression in keratinocytes through the TRPV1/STAT3 pathway. Moreover, low temperature-mediated inhibition of FLG and LOR was recovered, and TEWL was decreased in organotypic skin transfected with TRPV1 siRNA.
Conclusion:
TRPV1 is critical in low temperature-mediated skin barrier dysfunction. Low temperature exposure induced thymic stromal lymphopoietin, an alarmin implicated in epicutaneous allergen sensitization.
Probiotics are well known to act upon intestinal dysbiosis. Their effect on skin health is not as disclosed as on the intestinal front, but through oral administration the indirect effect on skin has been reported. Recently, the topical probiotic application has received more attention under the premise that applying probiotics directly to the skin will positively affect the local skin microbiome. While to date there have not been many clinical trials looking at topical probiotics for skin conditions, research so far suggests that they may prevent growth of harmful bacteria through competitive exclusion, production of chemical substances such as bacteriocins, organic acids and hydrogen peroxide, promotion of mucins secretion leading to the improvement of barrier function, stimulation of defensins release from the host cells, production of growth substances (vitamins) and competition for nutrients. In this chapter, we look at the skin structure and its microbiome and evaluate the role of probiotics on the normal function of healthy skin as well as their role in the prevention and therapy of skin disease.
To analyze the triggers of atopic dermatitis (AD), adherence to medical recommendations, disease control, and health-related quality of life (HRQOL) from the patient's perspective.
This was a multicenter, cross-sectional, epidemiological study with the participation of adults (age >16 years; n=125) and children (age, 2-15 years, n=116). Patients had a history of at least 12 months of moderate to severe AD with a moderate to severe flare (Investigator Global Assessment score>2) at the time of recruitment. The Mann-Whitney U test was used to evaluate relationships between disease severity, determined according to the Scoring in Atopic Dermatitis index, and triggers reported by patients, adherence to recommendations and pharmacological therapy, HRQOL, and patient-perceived control.
The most common triggers were cosmetic products, clothing, mites, detergents/soaps, and changes in temperature. In 47.2% of adults and 39.7% of children, pharmacological therapy was not initiated at flare onset. Adherence was highest to pharmacological therapy, skin moisturizing, and medical care recommendations. Disease control was considered insufficient by 41.6% of adults and 27. 6% of pediatric patients and, in adults, this was associated with the severity of AD (P=.014).
The therapeutic control of AD is susceptible to improvement, especially in adults. Although patients state that they follow medical recommendations, a significant percentage of patients do not apply recommended treatments correctly. Better education about the disease and its management would appear to be necessary to improve disease control and HRQOL.
Dermal exposure to alkaline agents may lead to skin barrier damage and irritant contact dermatitis. The objective of this study was to investigate the effects of cumulative exposure to 0.5% sodium lauryl sulphate (SLS) and 0.15% NaOH on the barrier function and natural moisturising factor (NMF) levels in atopic dermatitis and healthy volunteers with known filaggrin genotype. The skin response was monitored by measurement of erythema and transepidermal water loss. The stratum corneum NMF levels were determined by high-performance liquid chromatography. Repeated exposure to 0.5% SLS and/or 0.15% NaOH in atopic dermatitis resulted in more severe impairment of the skin barrier function. Cumulative exposure to these irritants reduced significantly NMF in both the atopic and healthy controls group. The pronounced decrease of NMF after repeated single and sequential irritant exposure may be a pathogenetically relevant factor for development of chronic irritant contact dermatitis in both healthy and atopic individuals.
Laypeople commonly perceive some skin xerosis and withering (roughness) changes during winter on some parts of the body, particularly on the dorsal hands. The aim of the study was to assess the withered skin surface changes occurring during the four seasons. A total of 47 menopausal women completed the study. A group of 31 volunteers were on hormone replacement therapy (HRT) and 16 were out of HRT. Skin xerosis and scaliness were rated clinically. In addition, skin whitening was assessed by computerized shadow casting optical profilometry and by skin capacitance mapping. The volunteers were not using topical creams and over-the-counter products on their hands. Marked changes, recorded over the successive seasons, corresponded to patchy heterogeneous stratum corneum hydration and heterogeneous skin surface roughness changing over seasons; they likely resulted from changes in the environmental temperature and atmosphere moisture. The severity of the changes revealed by clinical inspection was not supported by similar directions of fluctuations in the instrumental assessments. This seemingly contradiction was in fact due to different levels of scale observation. The clinical centimetric scale and the instrumental inframillimetric scale possibly provide distinct aspects of a given biological impact.
The total number of new attendant patients diagnosed as having atopic dermatitis at our dermatology outpatient clinic during the 7 year period from 1989 to 1995 was 10 156. Patients from each year during this period were divided into eight age groups. The birth month and the month of first visit for each age group was obtained in average of 7 years. Only for subjects aged < 1 year was there a definite tendency for higher birth numbers in autumn and lower birth numbers in spring. The percent birth rate for subjects < 1 year of age was significantly higher in October and November and significantly lower in March and May in comparison with the expected percent birth rates calculated on the basis of birth months of the Japanese population. Similarly, patients aged < 1 year, 1-2 and 3-5 years showed a tendency for higher numbers of first visits in spring and, in addition, patients aged < 1 year showed a tendency for smaller numbers of first visits in summer. At school and college ages, between 6 and 20 years of age, a steep increase of first visits was observed in March and a smaller increase of first visits was observed between July and August. We investigated whether the distribution of birth month for subjects aged < 1 year was statistically significant. The percent first visiting month was significantly higher in March and April and lower between July and October in comparison with the expected percentage first visiting month. We speculated that the uneven distribution of birth month was a reflection of a more marked distortion observed in the distribution of the month of first visit. The mean age at first visit (6.24 months) explains the difference between first visiting month and birth month. There were no definite social reasons for the increase in the number of first visits in spring for subjects aged < 1 year. Therefore, the uneven distribution of the month of first visit for subjects aged < 1 year could probably be the result of climatic effects.
Skin disorders such as atopic dermatitis, psoriasis and senile xerosis show a tendency to exacerbate in winter. We investigated the seasonal influence on the functional parameters of the skin in healthy female volunteers of different age groups. Biophysical noninvasive measurements, including transepidermal water loss (TEWL) as a parameter for the barrier function of the stratum corneum (SC), high-frequency conductance as a parameter for the hydration state of the SC, temperature, color and casual surface lipid levels, were conducted during the later summer and winter months in 39 healthy adult Japanese females ranging in age from 24 to 78 years. The measurements were made on the cheek, the exposed area, and flexor forearm, the semicovered area, in the same climate-controlled chamber. The barrier function of the SC was found to be significantly impaired in winter both on the cheek and flexor forearm. This difference between summer and winter was much larger on the cheek than on the forearm. The hydration state of the SC was significantly lower in winter on the flexor forearm, whereas no such seasonal change was apparent on the cheek where sebum levels did not show any seasonal change. We measured the corneocyte size in 24 out of the 39 subjects to estimate a seasonal change of the turnover rate of the SC. It tended to be smaller only on the exposed cheek skin, suggesting an enhanced turnover of the SC in winter, whereas it was somewhat larger on the semicovered flexor forearm. The skin surface temperature and redness were also significantly higher on the cheek in winter. We think that subclinical inflammation resulted in the enhanced turnover rate of the SC associated with elevated TEWL levels observed on the face in winter. In conclusion, the obtained data suggest that the exposed facial skin becomes more irritable under the influence of the dry and cold environment of winter even in healthy individuals where the barrier function of the SC is relatively poor as compared to the skin of other areas.
Atopic dermatitis (AD, atopic eczema) is driven by a complex relationship between genetic predisposition and environmental exposures. We sought to determine the impact of specific climatic factors on the US prevalence of AD. We used a merged analysis of the 2007 National Survey of Children's Health from a representative sample of 91,642 children age 0-17 years and the 2006-2007 National Climate Data Center and Weather Service measurements of relative humidity (%), indoor heating degree days (HDD), clear sky UV indices ozone levels, and outdoor air temperature. As a proxy for AD, we used an affirmative response to the NSCH survey question asking whether the participant's child has been given a doctor diagnosis of "eczema or any other kind of skin allergy" in the previous 12 months. In multivariate models controlling for sex, race/ethnicity, age and household income, eczema prevalence was significantly lower with highest-quartile mean annual relative humidity (logistic regression, adjusted odds ratio [95% confidence interval]=0.82 [0.71-0.96], P=0.01) and issued UV index (0.73 [0.64-0.84], P<0.0001), and with two other factors associated with increased UV exposure. Eczema prevalence was decreased with highest-quartile air temperature (0.80 [0.70-0.92], P=0.002), but increased with 3rd-quartile mean annual HDD (1.26 [1.11-1.43], P=0.0003). This study provides evidence of climate influences on the US prevalence of childhood eczema.Journal of Investigative Dermatology accepted article preview online, 18 January 2013; doi:10.1038/jid.2013.19.
Filaggrin null mutations result in impaired skin barrier functions, increase the risk of early onset atopic dermatitis and lead to a more severe and chronic disease. We aimed to characterize the clinical presentation and course of atopic dermatitis associated with filaggrin mutations within the first 7 years of life.
The COPSAC cohort is a prospective, clinical birth cohort study of 411 children born to mothers with a history of asthma followed during their first 7 years of life with scheduled visits every 6 months, as well as visits for acute exacerbations of dermatitis. Atopic dermatitis was defined in accordance with international guidelines and described at every visit using 35 predefined localizations and 10 different characteristics.
A total of 170 (43%) of 397 Caucasian children developed atopic dermatitis. The R501X and/or 2282del4 filaggrin null mutations were present in 26 (15%) of children with atopic dermatitis and were primarily associated with predilection to exposed skin areas (especially the cheeks and back of the hands) and an up-regulation of both acute and chronic dermatitis. Furthermore, we found the filaggrin mutations to be associated with a higher number of unscheduled visits (3.6 vs. 2.7; p = 0.04) and more severe (moderate-severe SCORAD 44% vs. 31%; p = 0.14), and widespread dermatitis (10% vs. 6% of the body area, p<0.001) with an earlier age at onset (246 vs. 473 days, p<0.0001) compared to wild-type.
In children, filaggrin mutations seem to define a specific endotype of atopic dermatitis primarily characterized by predilection to exposed areas of the body, in particular hands and cheeks, and an up-regulation in both acute and chronic morphological markers. Secondary, this endotype is characterized by an early onset of dermatitis and a more severe course, with more generalized dermatitis resulting in more frequent medical consultations.
Exposure to harsh environmental conditions, such as cold and dry
climate and chemicals can have an abrasive effect on skin. Skin
care products containing ingredients that avert these noxious
effects by reinforcement of the barrier function can be tested
using in vivo models. The objective is to use in vivo models to
assess the efficacy of emollients in protecting skin against
climatic and chemical insults. A first model used a stream of
cooled air to mimic cold wind. A second used sodium lauryl sulfate
(SLS) under patch as chemical aggressor. In the model with
simulated wind exposure, the untreated exposed area had a
significant decrease in hydration. In contrast, application of an
emollient caused a significant increase in hydration that was
maintained after wind exposure. In the second model with SLS
exposure, application of a barrier cream before SLS patch
significantly reduced the dehydrating effect of SLS with a
significant difference in variation between both areas.
Application of the cream reduced TEWL, indicative of a physical
reinforcement of the skin barrier. The two presented test methods,
done under standardized conditions, can be used for evaluation of
protective effect of emollient, by reinforcing the barrier
function against experimentally induced skin dehydration.
To clarify the prevalence of skin disorders among dermatology patients in Japan, a nationwide, cross-sectional, seasonal, multicenter study was conducted in 69 university hospitals, 45 district-based pivotal hospitals, and 56 private clinics (170 clinics in total). In each clinic, information was collected on the diagnosis, age, and gender of all outpatients and inpatients who visited the clinic on any one day of the second week in each of May, August, and November 2007 and February 2008. Among 67,448 cases, the top twenty skin disorders were, in descending order of incidence, miscellaneous eczema, atopic dermatitis, tinea pedis, urticaria/angioedema, tinea unguium, viral warts, psoriasis, contact dermatitis, acne, seborrheic dermatitis, hand eczema, miscellaneous benign skin tumors, alopecia areata, herpes zoster/postherpetic neuralgia, skin ulcers (nondiabetic), prurigo, epidermal cysts, vitiligo vulgaris, seborrheic keratosis, and drug eruption/toxicoderma. Atopic dermatitis, impetigo, molluscum, warts, acne, and miscellaneous eczema shared their top-ranking position in the pediatric population, whereas the most common disorders among the geriatric population were tinea pedis, tinea unguium, psoriasis, seborrheic dermatitis, and miscellaneous eczema. For some disorders, such as atopic dermatitis, contact dermatitis, urticaria/angioedema, prurigo, insect bites, and tinea pedis, the number of patients correlated with the average high and low monthly temperatures. Males showed a greater susceptibility to some diseases (psoriasis, erythroderma, diabetic dermatoses, inter alia), whereas females were more susceptible to others (erythema nodosum, collagen diseases, livedo reticularis/racemosa, hand eczema, inter alia). In conclusion, this hospital-based study highlights the present situation regarding dermatological patients in the early 21st century in Japan.
The facial skin of 354 women, aged 18–80, living in Shanghai, was investigated over two successive 6 month periods, summer and winter. Results from clinical assessments indicate that aging signs, such as wrinkling and sagging, are unaffected over such period.
However, physical measurements revealed alterations in some functional criteria of the skin, such as sebum output, skin colour, melanin content of pigmented spots, skin hydration, all being increased during summer. The relationships between all criteria, as well as technical or applied inferences/consequences from this study, are discussed.
La peau du visage de 354 femmes résidant à Shanghai, âgées de 18 à 80 ans a été observée à deux périodes successives, été et hiver. Les résultats des évaluations cliniques montrent que
Les signes liés au vieillissement, tels que rides et affaissement des traits, ne sont pas modifiés durant ces périodes.
En revanche, des modifications de certains critères fonctionnels cutanés ont été observées par les mesures physiques, telle la production sébacée, la couleur de la peau, le contenu mélanique des taches pigmentaires, l’hydratation, tous étant augmentés au cours de l’été.
Les relations entre ces critères, ainsi que les conséquences techniques ou appliquées résultant de cette étude, sont discutées.
Mutations in the gene-encoding filaggrin (FLG), a key molecule involved in skin barrier function, have been shown to be a major predisposing factor for atopic dermatitis (AD; eczema). To elucidate the pathomechanisms underlying filaggrin-related AD, we investigated stratum corneum (SC) hydration and transepidermal water loss (TEWL) as parameters of barrier function in AD patients harboring FLG mutations compared to AD patients without any FLG mutation. In filaggrin-related AD, SC hydration was both significantly reduced (P<0.01-0.05) and thicker (P<0.01-0.05) than that in healthy controls. TEWL was demonstrably increased in non-filaggrin AD compared to healthy controls (P<0.01-0.05). The objective score of atopic dermatitis (OSCORAD), a disease clinical severity index, significantly correlated with TEWL (r=0.81, P<0.005), SC hydration (r=-0.65, P<0.05), and SC thickness (r=0.59, P<0.05) in filaggrin-related AD. On the contrary, there was no correlation between these parameters and the OSCORAD in non-filaggrin AD. Furthermore, a significant correlation was obtained between the OSCORAD and specific IgE for house dust (r=0.66, P<0.05), mite allergen (r=0.53, P<0.05), and cat dander (r=0.64, P<0.05) in filaggrin-related AD, but not in non-filaggrin AD. All these data suggest that experimentally demonstrable skin barrier defects due to FLG mutations may play a crucial role in the pathogenesis of AD.
An accurate diagnosis of (occupational) contact sensitization by patch testing is a prerequisite for efficient preventive management. However, previously observed seasonal fluctuations in patch-test reactions indicate some influence of meteorological conditions. The present analysis aims at quantifying the possible impact of temperature and humidity on patch-test reactions to occupationally related allergens.
Clinical data from 61 780 patients tested with standard series allergens potentially related to occupational exposure from 1993 through 2001 were collected by a contact sensitization surveillance network.The association between the patch-test results and meteorological data (air temperature and humidity) collected at the time and the approximate location of the testing was analyzed in a multinomial logistic regression analysis.
For three allergens (a dye and two biocides), the odds of irritant or doubtful allergic reactions increased during cold and arid conditions. Two of them (pphenylenediamine and formaldehyde) also showed an association between weak positive allergic reactions and such weather. In contrast, reactions to various adhesive, plastic, and rubber-related allergens were not associated with weather conditions.
An overall increase in skin irritation, brought on by cold and dry conditions, may instigate an increase in positive reactions by leading doubtful allergic reactions to be (falsely) categorized as allergic for at least two of the considered allergens. For the most part, however, weather conditions were not associated with reactions to occupational allergens. Thus the validity of patch testing does not largely seem to be compromised by ambient meteorological conditions.
The objective of this study was to evaluate the effect of air humidification on (a) the dryness of the skin and mucosa, (b) allergic and asthmatic reactions, and (c) the perception of indoor air quality. A total of 290 office workers at the Pasila Office Center were included in a six-period cross-over trial. One wing of the building was operated with 30-40% humidification, and the other wing operated under conditions of no air humidification (relative humidity from natural conditions was 20-30%). The length of each study period was 1 work wk. The workers were instructed to keep a structured daily diary of their symptoms, their perception of the indoor air, and potential determinants of the symptoms. A total of 211 (72.6%) workers who returned at least two weekly diaries, and who had experienced both humidified and nonhumidified conditions, were included in the analyses. The primary outcome--dryness symptom score--was characterized by dryness, irritation or itching of the skin and eyes, dryness or irritation of the throat, and nasal dryness. Means of the daily symptom scores and perception ratings during the humidified and nonhumidified periods were calculated for each participant, and intraindividual differences in the means were used to assess the effect of air humidification. The dryness symptom score was significantly smaller during the humidified phase than during the reference phase (paired t test; p less than .05). Allergic symptoms that were considered as a separate outcome, a sensation of dryness, and draft were also significantly less frequent during the humidification phase (p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Bioengineering of the skin, or more precisely the biophysical assessment of skin physiology, is moving rapidly from a descriptive approach to a deeper understanding of biophysical and biochemical processes. This second edition of the popular text Bioengineering of the Skin: Water and Stratum Corneum reflects the progress in the field, focusing on t.
Among the beneficial properties claimed for dermatological and cosmetic products, “moisturizing” is possibly the most widely used. This term has been coined after the now classic observations of Blank,1,2 who discovered the plasticizing effect of water in the stratum corneum (SC). A common skin surface disturbance, xerosis, or so-called dryness of the skin, is experienced by most persons at some time, by a few persons all the time, and by all individuals increasingly as they grow older.3 Thus, as consumers advance in age, concern about dry skin increases. In addition, moist, clean, soft, and wrinkle-free skin is perceived as youthful, and for this reason, moisturizers are widely used, and skin care with these products is regarded as a dominant growth area in cosmetics and toiletries.
It is well established that the various dimensions of individual corneocytes (diameter, surface area) follow constant rules. There are pronounced regional variations for different topographical sites [8] and also quite distinct changes with age [1, 5, 6], older people having much larger corneocytes than younger subjects [9]. This biological rule also holds for corneocytes from the nail plates [2]. Measurements of corneocytes removed using the Triton X-100 scrubbing technique are accurate, reproducible, and do not show greater than 3% error [7,10]. It was not known whether there might be seasonal variations in the size of corneocytes. There are pronounced seasonal differences in the weather in Munich, with an average summer temperature of 17.2 °C (July) and winter temperature of −2.4 °C (January) with relative humidity of 72% and 84% respectively.
The epidermis functions as a barrier against the environment by means of several layers of terminally differentiated, dead keratinocytes - the cornified layer, which forms the endpoint of epidermal differentiation and death. The cornified envelope replaces the plasma membrane of differentiating keratinocytes and consists of keratins that are enclosed within an insoluble amalgam of proteins, which are crosslinked by transglutaminases and surrounded by a lipid envelope. New insights into the molecular mechanisms and the physiological endpoints of cornification are increasing our understanding of the pathological defects of this unique form of programmed cell death, which is associated with barrier malfunctions and ichthyosis.
Background
Filaggrin (FLG) is a major protein component of the stratum corneum (SC) layer, and FLG loss-of-function mutations are a predisposing factor for atopic dermatitis (AD). Previous cohort studies of children from northern and western Europe have reported FLG loss-of-function mutation frequencies of 15.1–20.9% and 5.8–13.0% in AD and non-AD groups, respectively.
Objective
To elucidate the association between AD prevalence of FLG loss-of-function mutation carriers and climate conditions, we determined the AD prevalence and FLG loss-of-function mutation frequencies in a cohort of children from Ishigaki Island. Ishigaki Island has a subtropical climate with high humidity (monthly average, 60.8–78.7%) and high temperature (monthly average, 18.5–29.4 °C) throughout the year.
Methods
We diagnosed AD prevalence and analyzed eight FLG loss-of-function mutations in the Japanese population against a cohort of 721 children from the Kyushu University Ishigaki Atopic Dermatitis Study (KIDS) cohort. Parents gave consent for the mutation analysis during their medical examinations from 2001–2006.
Results
Average AD prevalence was 7.3% per year, and a total of 127 children (17.6%) were diagnosed with AD at least once between 2001 and 2006. The average total serum IgE level differed significantly between the AD and non-AD groups (199.0 and 69.0 IU/ml, respectively). Although five kinds of FLG loss-of-function mutations isolated in previous Japanese FLG mutation studies were identified, the FLG loss-of-function mutation frequency in children of the KIDS cohort was not significantly different between the AD and non-AD groups (7.9% and 6.1%, respectively; P = 0.174).
Conclusion
The FLG loss-of-function mutation frequency was not significantly different between the AD and non-AD groups in a cohort of children from Ishigaki Island, which has a subtropical climate, suggesting that FLG loss-of-function mutations are not always a predisposing factor for AD prevalence.
Introduction and objectives
To analyze the triggers of atopic dermatitis (AD), adherence to medical recommendations, disease control, and health-related quality of life (HRQOL) from the patient's perspective.
Patients and methods
This was a multicenter, cross-sectional, epidemiological study with the participation of adults (age > 16 years; n = 125) and children (age, 2-15 years, n = 116). Patients had a history of at least 12 months of moderate to severe AD with a moderate to severe flare (Investigator Global Assessment score > 2) at the time of recruitment. The Mann-Whitney U test was used to evaluate relationships between disease severity, determined according to the Scoring in Atopic Dermatitis index, and triggers reported by patients, adherence to recommendations and pharmacological therapy, HRQOL, and patient-perceived control.
Results
The most common triggers were cosmetic products, clothing, mites, detergents/soaps, and changes in temperature. In 47.2% of adults and 39.7% of children, pharmacological therapy was not initiated at flare onset. Adherence was highest to pharmacological therapy, skin moisturizing, and medical care recommendations. Disease control was considered insufficient by 41.6% of adults and 27. 6% of pediatric patients and, in adults, this was associated with the severity of AD (P = .014).
Conclusions
The therapeutic control of AD is susceptible to improvement, especially in adults. Although patients state that they follow medical recommendations, a significant percentage of patients do not apply recommended treatments correctly. Better education about the disease and its management would appear to be necessary to improve disease control and HRQOL.
Age, gender, regional, and ethnic differences influence skin conditions. The purpose of this study was to observe the effects of environments, especially the air temperature, relative humidity, air pressure, duration of sunshine, and precipitation on skin, and the seasonal variation in skin hydration, sebum, scales, brightness, and elasticity in Korean females.
The study included 89 Korean subjects, aged 29.7 ± 6.2 years. The five skin biophysical parameters (skin hydration, sebum, scales, brightness, and elasticity) were measured at six sites: forehead, under the eye, frontal cheek, crow's foot, lateral cheek, and inner forearm. Skin hydration was measured using the Corneometer(®) CM 825. Skin sebum was measured with Sebumeter(®) SM 815. Skin scaliness was measured with Visioscan(®) VC 98. Skin brightness (L* value) was measured by using Spectrophotometer. A suction chamber device, Cutometer(®) MPA 580, was used to measure the skin elasticity. The measurements were performed every month for 13 months, from April 2007 to April 2008.
There were significantly seasonal variations in environmental factors. The air temperature was the lowest in January (-1.7°C), and the highest in August (26.5°C). The relative humidity was the lowest in February (46%), and the highest in July and August (75%). There was a negative correlation between skin scaliness and three environmental factors such as air temperature, relative humidity, and highest precipitation. There was a positive correlation between skin scaliness and two environmental factors such as air pressure and duration of sunshine. Elasticity was correlated with air temperature positively and with air pressure negatively.
The correlations shown between the skin biophysical parameters and environmental factors demonstrate that the skin biophysical parameters are affected by environmental factors.
Irritant hand dermatitis (IHD) is common in health care workers.
We studied endogenous irritant contact dermatitis threshold by patch testing and exogenous factors such as season and hand washing for their association with IHD in health care workers.
Irritant patch testing with sodium lauryl sulfate (SLS), sodium hydroxide, and benzalkonium chloride at varying concentrations was measured in 113 health care workers. Examination for hand dermatitis occurred at 1-month intervals for a period of 6 months in the Midwestern United States.
Positive patch testing to low-concentration SLS was associated with IHD (P = 0.0310) after adjusting for age, sex, ethnicity, season, history of childhood flexural dermatitis, mean indoor relative humidity, and glove and hand sanitizer usage. Subjects with a positive patch test to SLS were 78% more likely to have occurrence of IHD (incidence rate ratio [IRR] = 1.78; 95% confidence interval [CI], 0.92-3.45). Hand washing frequency (≥10 times a day; IRR = 1.55; 95% CI, 1.01-2.39) and cold season (IRR = 2.76; 95% CI, 1.35-5.65) were associated with IHD. No association was found between history of childhood flexural dermatitis and IHD in this population.
Both genetic and environmental factors are important in the etiology of IHD and should be considered in designing strategies to protect, educate, and treat susceptible individuals.
Background: Xerosis, a well-known problem in the elderly part of the population, is often exacerbated in winter with negative effects on daily life. Objective: To describe differences in stratum corneum function of the lower legs in winter compared to summer using objective biometric methods. Methods: The following techniques were utilized: colorimetry, evaporimetry, laser Doppler perfusion imaging, sticky slides (D-Squames®) and corneometry. The reaction to a 24-hour patch test with sodium lauryl sulfate, burning to chloroform:methanol and the whealing response to dimethylsulfoxide were also studied. Results: In winter, the stratum corneum had a looser structure and a diminished barrier function with an increased neurosensory reactivity. Conclusion: The results suggest that the exacerbation of xerosis in the winter is accompanied by structural changes in the stratum corneum, making it looser and more permeable to chemical irritants with a heightened response to neurosensory stimuli.
Synopsis The susceptibility of the STRATUM CORNEUM to CHAPPING depends upon its mechanical properties such as extensibility. It has previously been shown that at constant temperature, extensibility of isolated corneum is related to RELATIVE HUMIDITY and that at constant relative humidity, extensibility increases when the temperature is raised above 25øC. In this report extensibility of isolated animal corneum has been determined at 5øC where skin chapping occurs more frequently. EXTENSIBILITY was found to be lower at reduced tem- peratures although the corneum water content did not decrease. It was concluded that skin chapping is the result of a low corneum TEMPERATURE and WATER CONTENT and that greater flaking and chapping of the surface corneum is a result of a gradient of temperature or water content across the corneum in a cold or dry ENVIRONMENT.
Skin hydration plays an important role in the optimal physical properties and physiological functions of the skin. Despite the advancements in the last decade, dry skin remains the most common characteristic of human skin disorders. Thus, it is important to understand the effect of hydration on Stratum Corneum (SC) components. In this respect, our interest consists in correlating the variations of unbound and bound water content in the SC with structural and organizational changes in lipids and proteins using a non-invasive technique: Raman spectroscopy. Raman spectra were acquired on human SC at different relative humidity (RH) levels (4-75%). The content of different types of water, bound and free, was measured using the second derivative and curve fitting of the Raman bands in the range of 3100-3700 cm(-1). Changes in lipidic order were evaluated using νC-C and νC-H. To analyze the effect of RH on the protein structure, we examined in the Amide I region, the Fermi doublet of tyrosine, and the νasymCH3 vibration. The contributions of totally bound water were found not to vary with humidity, while partially bound water varied with three different rates. Unbound water increased greatly when all sites for bound water were saturated. Lipid organization as well as protein deployment was found to be optimal at intermediate RH values (around 60%), which correspond to the maximum of SC water binding capacity. This analysis highlights the relationship between bound water, the SC barrier state and the protein structure and elucidates the optimal conditions. Moreover, our results showed that increased content of unbound water in the SC induces disorder in the structures of lipids and proteins.
BACKGROUND/AIMS: We studied annual, seasonal and gender-dependent changes in the intensity of facial wrinkles. METHODS: The study included 32 Japanese subjects (16 men, 16 women, aged 35-47). Wrinkles on the forehead, corner of the eye, lower eyelid and nasolabial groove of each subject were captured in photos and in replicas at 3-month intervals from March, 2009 to March, 2010. At each occasion, skin conductance in the stratum corneum and skin color were measured on the cheek. The photos obtained were used for visual scoring of wrinkle intensity, and the quantitative 3-D data of replicas were obtained. RESULTS: An apparent annual variation in skin conductance, which is supposed to be caused by skin dryness, and in the level of skin brightness, which is supposed to be caused by sun tan, was found for both genders. In contrast, no seasonal changes were determined in wrinkle intensity. Three-D analysis revealed no annual variation in women but revealed annual variation in the depths of eye wrinkles in men. CONCLUSION: There was a gender-dependent difference in the annual variation of wrinkle depth in subjects around 40 years of age. Seasonal environmental changes may affect on the eye wrinkles depth in men within a year.
The objective of this study was to clarify variations of the ceramide (CER) profile in human stratum corneum (SC) in different seasons and in different regions of the body and to estimate the contributions of CERs to the SC barrier and water-holding functions. Based on the information that there are great variations of SC functions among body sites, we compared the CER profiles obtained from ten different anatomical sites in healthy Japanese males in four seasons. Not only the physiological parameters of skin but also the CER profile showed body region and seasonal variations. The total CER level, the CER composition and the C34-CER[NS] species displayed strong correlations with the values of transepidermal water loss and capacitance throughout the body. Especially in the cheek, a strong correlation between the capacitance and the CER profile was observed. There were seasonal variations of the CER profile in the lip, upper arm and palm. Our results indicate that regional and seasonal variations of the CER profile may contribute to SC functions.
— As part of a study on the effect of water on the extensibility of isolated corneum we have investigated the effect of temperature on extensibility under conditions where the corneum water content was kept as constant as possible. The results showed that corneum extensibility was decreased at lower temperatures. These results may be of significance in the appearance of skin chapping in winter. The incidence of chapping has been related to low dewpoints and the hypothesis was that a low dewpoint leads to a low corneum water content. Our results suggest that low temperatures play an equally important part and that chapping is not related purely to a low corneum water content.
As a parallel project to a coronary risk factor survey in northern Norway, 14,667 men and women aged 18–55 years answered questions concerning the occurrence or allergic handeczema. 364 men (4.9%) and 961 women (13.2%) had had allergic hand eczema during the previous 12 months, 49 men (0.7%) and 105 women (1.4%) claimed to have had one or more sick leaves because of hand eczema during the preceding 3 years, 114 subjects reported both eczema last year and sick leave during the preceding 3 years, of whom 74 were already registered in the files of the regional department of dermatology. The majority had irritant contact dermatitis. The incidence of hand eczema appears to be high in this part of Norway and the possibility that the subarctic climate may increase skin irritancy is discussed.
Atopic eczema (AE) is a chronic skin disease. Recent reports indicate that the worldwide prevalence of AE is increasing and
that various environmental factors are implicated in its aetiology. Climatic conditions have been related with AE prevalence,
and Spain has varying climatic conditions. The aim of this study is to document the possible climatic influence on the prevalence
of AE in schoolchildren aged 6–7years in three different climatic regions in Spain. We conducted a cross-sectional population-based
survey of 28,394 schoolchildren aged 6–7years from 10 Spanish centres in three different climatic regions. The mean participation
rate was 76.5%. AE prevalence was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire
and the Spanish Academy of Dermatology criteria used in Spain to diagnose AE. The data, including annual temperature, precipitation,
relative humidity and the annual number of sunny hours per climatic region, were obtained from the Spanish National Institute
of Meteorology. Different AE prevalences were found in all three climatic regions studied: Atlantic, 32.9; Mediterranean 28.3;
and Continental 31.2 per 100 children studied (p < 0.005). AE was positively associated with precipitation and humidity, and was negatively associated with temperature and
the number of sunny hours. The results show that AE is significantly dependent on meteorological conditions.