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Skin Exposome

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Abstract

This chapter provides an overview of the most important skin exposome factors impacting skin aging and discusses the role of exposome factors in specific skin conditions such as atopic dermatitis, and acne. It includes some suggestions on how to limit impact of the exposome on skin. Skin aging combines two processes: intrinsic aging, the normal genetic processes that occur with time, and extrinsic aging, or accelerated aging, from exposure to skin exposome factors. The chapter focuses on exposome factors directly implicated in skin aging: exposure to solar radiation, air pollution, and tobacco smoking. The skin is directly affected by climate change, such as fluctuating humidity and temperature, and changes in the amount and type of irradiation. Climate change is expected to increase the impact of solar rays resulting in accelerated photoaging and increased incidences of certain skin cancers. A daily cosmetic skin care routine can help correct and prevent the negative effects of exposome exposure.

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The skin is the main barrier that protects us against environmental stressors (physical, chemical, and biological). These stressors, combined with internal factors, are responsible for cutaneous aging. Furthermore, they negatively affect the skin and increase the risk of cutaneous diseases, particularly skin cancer. This review addresses the impact of environmental stressors on skin aging, especially those related to general and specific external factors (lifestyle, occupation, pollutants, and light exposure). More specifically, we have evaluated ambient air pollution, household air pollutants from non-combustion sources, and exposure to light (ultraviolet radiation and blue and red light). We approach the molecular pathways involved in skin aging and pathology as a result of exposure to these external environmental stressors. Finally, we reflect on how components of environmental stress can interact with ultraviolet radiation to cause cell damage and the critical importance of knowing the mechanisms to develop new therapies to maintain the skin without damage in old age and to repair its diseases.
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Indoor and outdoor airborne pollutants modify our environment and represent a growing threat to human health worldwide. Airborne pollution effects on respiratory and cardiac health and diseases have been well established, but its impact on skin remains poorly described. Nonetheless, the skin is one of the main targets of pollutants, which reach the superficial and deeper skin layers by transcutaneous and systemic routes. In this review, we report the outcomes of basic and clinical research studies monitoring pollutant levels in human tissues including the skin and hair. We present a current understanding of the biochemical and biophysical effects of pollutants on skin metabolism, inflammatory processes and oxidative stress, with a focus on polyaromatic hydrocarbons and ground‐level ozone that are widespread outdoor pollutants whose effects are mostly studied. We reviewed the literature to report the clinical effects of pollutants on skin health and skin aging and their impact on some chronic inflammatory skin diseases. We also discuss the potential interactions of airborne pollutants with either ultraviolet radiation, or human skin microbiota and their specific impact on skin health. This article is protected by copyright. All rights reserved.
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To investigate whether sleep deprived people are perceived as less healthy, less attractive, and more tired than after a normal night's sleep. Experimental study. Sleep laboratory in Stockholm, Sweden. 23 healthy, sleep deprived adults (age 18-31) who were photographed and 65 untrained observers (age 18-61) who rated the photographs. Participants were photographed after a normal night's sleep (eight hours) and after sleep deprivation (31 hours of wakefulness after a night of reduced sleep). The photographs were presented in a randomised order and rated by untrained observers. Difference in observer ratings of perceived health, attractiveness, and tiredness between sleep deprived and well rested participants using a visual analogue scale (100 mm). Sleep deprived people were rated as less healthy (visual analogue scale scores, mean 63 (SE 2) v 68 (SE 2), P<0.001), more tired (53 (SE 3) v 44 (SE 3), P<0.001), and less attractive (38 (SE 2) v 40 (SE 2), P<0.001) than after a normal night's sleep. The decrease in rated health was associated with ratings of increased tiredness and decreased attractiveness. Our findings show that sleep deprived people appear less healthy, less attractive, and more tired compared with when they are well rested. This suggests that humans are sensitive to sleep related facial cues, with potential implications for social and clinical judgments and behaviour. Studies are warranted for understanding how these effects may affect clinical decision making and can add knowledge with direct implications in a medical context.
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The purpose of this study was to determine the effect of visible light on the immediate pigmentation and delayed tanning of melanocompetent skin; the results were compared with those induced by long-wavelength UVA (UVA1). Two electromagnetic radiation sources were used to irradiate the lower back of 20 volunteers with skin types IV-VI: UVA1 (340-400 nm) and visible light (400-700 nm). Pigmentation was assessed by visual examination, digital photography with a cross-polarized filter, and diffused reflectance spectroscopy at 7 time points over a 2-week period. Confocal microscopy and skin biopsies for histopathological examination using different stains were carried out. Irradiation was also carried out on skin type II. Results showed that although both UVA1 and visible light can induce pigmentation in skin types IV-VI, pigmentation induced by visible light was darker and more sustained. No pigmentation was observed in skin type II. The quality and quantity of pigment induced by visible light and UVA1 were different. These findings have potential implications on the management of photoaggravated pigmentary disorders, the proper use of sunscreens, and the treatment of depigmented lesions.
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Background: The role of skin microbiota in acne remains to be fully elucidated. Initial culture-based investigations were hampered by growth rate and selective media bias. Even with less biased genomic methods, sampling, lysis and methodology, the task of describing acne pathophysiology remains challenging. Acne occurs in sites dominated by Cutibacterium acnes (formerly Propionibacterium acnes) and Malassezia species, both of which can function either as commensal or pathogen. Objectives: This article aims to review the current state of the art of the microbiome and acne. Methods: The literature regarding the microbiome and acne was reviewed. Results: It remains unclear whether there is a quantitative difference in microbial community distribution, making it challenging to understand any community shift from commensal to pathogenic nature. It is plausible that acne involves (i) change in the distribution of species/strains, (ii) stable distribution with pathogenic alteration in response to internal (intermicrobe) or external stimuli (host physiology or environmental) or (iii) a combination of these factors. Conclusions: Understanding physiological changes in bacterial species and strains will be required to define their specific roles, and identify any potential intervention points, in acne pathogenesis and treatment. It will also be necessary to determine whether any fungal species are involved, and establish whether they play a significant role. Further investigation using robust, modern analytic tools in longitudinal studies with a large number of participants, may make it possible to determine whether the microbiota plays a causal role, is primarily involved in exacerbation, or is merely a bystander. It is likely that the final outcome will show that acne is the result of complex microbe-microbe and community-host interplay.
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As interest in complementary and alternative medicine has grown, the relationship between diet and skin health has become an active area of research. Various supplements, plant derivatives, and antioxidants have gained attention as possible tools to prevent signs of aging and improve skin conditions. As such, knowledge of clinical trial data is important to counsel patients appropriately on risks and benefits of these complementary treatments and lifestyle modifications. Herein, we review the role of diet and supplements in preventing photoaging and treating common skin conditions.
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Background The skin exposome refers to the constellation of external exposures that contribute to cutaneous aging, including solar radiation, air pollution, tobacco smoke, unbalanced nutrition, and cosmetic products. This review explores the skin exposome and the role of a combination hyaluronic acid and mineralized thermal water product used to restore and maintain optimal skin barrier function. Method An expert panel of 7 dermatologists who treat clinical signs of facial aging convened for a one‐day meeting to discuss the results of a literature review on the skin exposome and the role of M89, a mineralized thermal water and hyaluronic acid‐based gel, to improve the quality of facial skin. Evidence coupled with expert opinion and experience of the panel was used to address clinical challenges in the treatment of photo‐aging, and the use of M89. Results Solar radiation (ultraviolet radiation, visible light, and infrared radiation), air pollution, tobacco smoke, nutrition, and miscellaneous factors, including stress, sleep deprivation, and temperature, may potentiate skin aging by triggering molecular processes that damage skin structure. M89 was developed to maintain and restore skin and contains ingredients to aid physical, hydric, antioxidant, and antimicrobial skin barrier function. Conclusions Increasing knowledge of the exposome and microenvironment contributing to skin aging may support a better understanding of measures to support the skin. The initial results of in vitro and clinical studies of M89 show its potential to improve skin barrier function.
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Skin is an efficient protective barrier armed with an intricate network of antioxidants. External environmental stress diminishes and sometimes overwhelms these innate protective mechanisms; aging slows their efficacy. Topical antioxidants enhance natural endogenous defenses to create an indwelling reservoir for sustained protection with far higher concentrations than possible with oral intake. The challenge is creating formulations of these labile molecules that are stable, active, and can be effectively absorbed transdermally to deliver high concentrations. This article is protected by copyright. All rights reserved.
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Objective To study the effects of the very high minerality Vichy thermal spring water (VTSW) on human keratinocytes grown in vitro. Methods The effect of VTSW was monitored by full genome transcriptomic technology and immunofluorescence microscopy. Results In the presence of 50% VTSW, the expression of a number of skin homeostasis related genes is increased, specifically with respect to dermal‐epidermal junction, epidermal cohesion and communication, keratinocyte proliferation‐differentiation balance, antioxidant mechanisms and DNA repair. Conclusion The present work suggests that VTSW could be considered as an ingredient of potential interest to address some of the deleterious effects of skin aging exposome. This article is protected by copyright. All rights reserved.
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Despite commanding essentially universal scientific consensus, climate change remains a divisive and poorly understood topic in the United States. Familiarity with this subject is not just for climate scientists. The impact of climate change on human morbidity and mortality may be considerable; thus, physicians also should be knowledgeable in this realm. Climate change science can seem opaque and inferential, creating fertile ground for political polemics and undoubtedly contributing to confusion among the general public. This puts physicians in a pivotal position to facilitate a practical understanding of climate change in the public sphere by discussing changes in disease patterns and their possible relationship to a changing climate. This article provides a background on climate change for dermatologists and highlights how climate change may impact the management of skin disease across the United States.
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Background: It is likely that skin is exposed to low concentrations of pollutants such as Polycyclic Aromatic Hydrocarbons (PAH) either through topical penetration by ultrafine particles or by systemic distribution. No precise estimation of pollutants in living skin is available, but literature has reported contamination of blood by PAH at concentrations in the nanomolar range. Some pollutants (PAH for example) are photo-reactive and phototoxic: sunlight and pollution might thus synergistically compromise skin health. Objective: Here, the biological effects of particulate matter, PM extract and various PAH were compared in normal human epidermal keratinocytes (NHEK) and reconstructed skin model exposed to either daily UV (d-UV 300-400nm) or UVA1 (350-400nm). Impact of pollutants (PM, PAH or PM extract) combined to UV was studied on NHEK by measuring toxicity, redox homeostasis and GSH metabolism in NHEK. Methods: NHEK were exposed to UV from solar simulator (either d-UV or UVA1) combined with pollutants. Viability, clonogenic efficiency, redox homeostasis and GSH metabolism were assessed. Results: Pollutants (PAH, PM or PM extract) ±UVA1 irradiation was associated with a significant phototoxic effect that was equal to or greater than that produced by d-UV. This result is interesting considering that UVA1 represents around 80% of daily UV and reaches the dermal-epidermal junction with ease. Moreover, among PAH studied, benzo[a]pyrene and indeno[1,2,3-cd]pyrene were phototoxic at very low concentrations (nanomolar range) on cultured cells or in reconstructed epidermis and also impaired keratinocyte clonogenic potential at sub-toxic doses. ROS generation within cells and in the inner mitochondrial compartment, mitochondrial membrane depolarization and/or reduced ATP production were also noted. Meanwhile, intracellular glutathione concentrations transiently decreased several hours post-treatment and reduction of its synthesis by buthionine sulfoximine potentiated PAH phototoxicity. Consequently, expression of GSH neo-synthesis genes such as SLC7A11 or GCLc was upregulated several hours post-treatment. Conclusion: These results obtained using PAH concentrations in the range of those reported in blood of pollution-exposed people suggest that exposure to such a photo-pollution stress, particularly if chronic, may impair cutaneous homeostasis and aggravate sunlight-induced skin damage.
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Global temperatures continue to rise, reaching new records almost every year this decade. Although the causes are debated, climate change is a reality. Consequences of climate change include melting of the arctic ice cap, rising of sea levels, changes in precipitation patterns, and increased severe weather events. This article updates dermatologists about the effects of climate change on the epidemiology and geographic ranges of selected skin diseases in North America. Although globalization, travel, and trade are also important to changing disease and vector patterns, climate change creates favorable habitats and expanded access to immunologically naïve hosts. Endemic North American illnesses such as Lyme disease, leishmaniasis, and dimorphic fungal infections have recently expanded the geographic areas of risk. As temperatures increase, epidemic viral diseases such as hand-foot-and-mouth disease may develop transmission seasons that are longer and more intense. Chikungunya and dengue are now reported within the southern United States, with Zika on the horizon. Cutaneous injuries from aquatic and marine organisms that have expanding habitats and longer durations of peak activity include jellyfish envenomation, cercarial dermatitis, and seabather eruption, among others. Skin cancer rates may also be affected indirectly by changes in temperature and associated behaviors.
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The term “exposome” describes the totality of exposures to which an individual is subjected from conception to death. It includes both external and internal factors as well as the human body’s response to these factors. Current exposome research aims to understand the effects all factors have on specific organs, yet today, the exposome of human skin has not received major attention and a corresponding definition is lacking. This review was compiled with the collaboration of European scientists, specialized in either environmental medicine or skin biology. A comprehensive review of the existing literature was performed using PubMed. The search was restricted to exposome factors and skin aging. Key review papers and all relevant, epidemiological, in vitro, ex vivo and clinical studies were analyzed to determine the key elements of the exposome influencing skin aging. Here we propose a definition of the skin aging exposome. It is based on a summary of the existing scientific evidence for the role of exposome factors in skin aging. We also identify future research needs which concern knowledge about the interaction of distinct exposomal factors with each other and the resulting net effects on skin aging and suggest some protective measures.
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It has frequently been speculated that pruritus and skin lesions develop after topical exposure to aeroallergens in sensitized patients with atopic dermatitis (AD). We sought to study cutaneous reactions to grass pollen in adult patients with AD with accompanying clear IgE sensitization to grass allergen in an environmental challenge chamber using a monocenter, double-blind, placebo-controlled study design. Subjects were challenged on 2 consecutive days with either 4000 pollen grains/m(3) of Dactylis glomerata pollen or clean air. The severity of AD was assessed at each study visit up to 5 days after challenge by (objective) scoring of AD (SCORAD). Additionally, air-exposed and non-air-exposed skin areas were each scored using local SCORAD scoring and investigator global assessments. Levels of a series of serum cytokines and chemokines were determined by using a Luminex-based immunoassay. The primary end point of the study was the change in objective SCORAD scores between prechallenge and postchallenge values. Exposure to grass pollen induced a significant worsening of AD. A pronounced eczema flare-up of air-exposed rather than covered skin areas occurred. In grass pollen-exposed subjects a significantly higher increase in CCL17, CCL22, and IL-4 serum levels was observed. This study demonstrates that controlled exposure to airborne allergens of patients with a so-called extrinsic IgE-mediated form of AD induced a worsening of cutaneous symptoms. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Article
Objective Psychological stress is known to have a negative effect on a large number of skin diseases. However, there is little research on the relationship between psychological stress and the epidermal permeability barrier function (EPBF) of healthy individuals. We hypothesize that psychological stress deteriorates EPBF and aimed to investigate this relationship.Methods Psychological stress was assessed using salivary alpha-amylase (sAmy; KIU L-1) and chromogranin A level corrected with total protein (CgAP; pmol mg-1 protein) as psychological stress biomarkers. Measurements were obtained from 16 healthy female students during two periods of presumed higher stress (final examinations and returning from a long vacation) and a period considered as a control. The EPBF level was evaluated by measuring transepidermal water loss (TEWL; g m-2 h-1). The TEWL was measured three times: just before (TEWL [Intact]), immediately after (TEWL [Str]), and 4 h after (TEWL [4h]) barrier disruption by tape stripping. The rate of barrier disruption was evaluated by comparing the difference between the TEWL [Intact] and the TEWL [Str] (delta-BD: g m-2 h-1). The recovery was assessed by comparing the difference between the TEWL [Intact] and TEWL [4h] (delta-RE: g m-2 h-1).ResultsThe subjects demonstrated a significant increase in the sAmy value after the long vacation compared with the control. There was no change in the CgAP value between the groups. Meanwhile, the EPBF level showed significant deterioration during both higher stress periods. There was a significant increase in delta-BD and delta-RE after the long vacation.Conclusions The results indicate the possibility that psychological stress causes a decline in EPBF and deterioration in barrier disruption and recovery. Furthermore, it implies a relationship between psychological stress and the exacerbation or protracted healing of skin disease.This article is protected by copyright. All rights reserved.
Article
Background Sleep is important for growth and renewal of multiple physiological systems. The effects of chronic poor sleep quality on human skin function and visible signs of ageing have not been elucidated.AimTo evaluate the effect of chronic poor sleep quality on measures of skin health and ageing. Self-perceived satisfaction with appearance was also assessed.Methods60 healthy caucasian women, who were categorized as poor quality sleepers [Pittsburg Sleep Quality Index (PSQI) > 5, sleep duration ≤ 5 h] or good quality sleepers (PSQI ≤ 5, sleep duration 7–9 h). A validated clinical tool, SCINEXATM, was used to assess intrinsic and extrinsic skin ageing. Dark under-eye circles were evaluated using standardized photos. Measurement of in vivo transepidermal water loss (TEWL) was used to assess recovery of the skin barrier after tape stripping. Subjects were exposed to simulated solar ultraviolet light, and recovery from erythema was monitored. Subjects also completed a questionnaire evaluating self-perception of attractiveness.ResultsGood sleepers had significantly lower intrinsic skin ageing scores by SCINEXATM. At baseline, poor sleepers had significantly higher levels of TEWL. At 72 h after tape stripping, good sleepers had 30% greater barrier recovery compared with poor sleepers. At 24 h after exposure to ultraviolet light, good sleepers had significantly better recovery from erythema. Good sleepers also reported a significantly better perception of their appearance and physical attractiveness compared with poor sleepers.Conclusions This study indicates that chronic poor sleep quality is associated with increased signs of intrinsic ageing, diminished skin barrier function and lower satisfaction with appearance.
Article
UVA radiation is the most prevalent component of solar UV radiation; it deeply penetrates into the skin and induces profound alterations of the dermal connective tissue. In recent years, the detrimental effects of UVA radiation were more precisely demonstrated at cellular and molecular levels, using adequate methods to identify biological targets of UVA radiation and the resulting cascade impairment of cell functions and tissue degradation. In particular gene expression studies recently revealed that UVA radiation induces modulation of several genes confirming the high sensitivity of dermal fibroblasts to UVA radiation. The major visible damaging effects of UVA radiation only appear after years of exposure: it has been clearly evidenced that they are responsible for more or less early signs of photoageing and photocarcinogenesis. UVA radiation appears to play a key role in pigmented changes occurring with age, the major sign of skin photoaging in Asians. Skin susceptibility to photoaging alterations also depends on constitutive pigmentation. The skin sensitivity to UV light has been demonstrated to be linked to skin color type.
Article
In recent years, the health effects associated with air pollution have been intensively studied. Most studies focus on air pollution effects on the lung and the cardiovascular system. More recently however, epidemiological and mechanistic studies suggest that air pollution is also affecting skin integrity. This state-of-the art review focuses on this latter aspect; it was developed with the collaboration of European and Chinese board of experts with specific interests in environmental health, clinical and basic research in dermatology and cosmetic dermatology. A literature review limited to pollution and health effects and (sensitive) skin was performed using PubMed. Review and original articles were chosen. We summarize the existing scientific evidence that air pollution exerts detrimental effects on human skin, discuss potential clinical implications and suggest specific and unspecific cosmetic protective measures.
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Environmental factors, here taken to include pollutants, lifestyle factors and behaviours, can play an important role in serious, chronic pathologies with large societal and economic costs, including respiratory disease. However, measurement of the environmental component in epidemiological studies has traditionally relied on much more uncertain and incomplete assessments than measurement of the genome. The 'exposome' has therefore been proposed as a new paradigm to encompass the totality of human environmental (meaning all non-genetic) exposures from conception onwards, complementing the genome. Evidently, there are large challenges in developing the exposome concept into a workable approach for epidemiological research. These include: (1) the accurate and reliable measurement of many exposures in the external environment, (2) the measurement of a wide range of biological responses in the internal environment, and (3) addressing the dynamic, life course nature of the exposome. New tools and technologies that can be applied to address these challenges include exposure biomarker technologies, geographical mapping and remote sensing technologies, smartphone applications and personal exposure sensors, and high-throughput molecular 'omics' techniques. Prospective, population-based cohort studies have recently started to implement these methods using the exposome framework. The exposome thus offers a new and exciting paradigm for improvement and integration of currently scattered and uncertain data on the environmental component in disease aetiology. This should lead to a better understanding of the role of environmental risk factors in respiratory disease and other chronic pathologies, and ultimately to better primary prevention strategies.
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The visible light spectrum is wide, and it can be hypothesized that all the wavelengths between 400-700nm do not induce the same photobiological effects on pigmentation. We assessed the potential pro-pigmenting effects of two single wavelengths located at both extremities of the visible spectrum: the blue/violet line (λ=415nm), and the red line (λ=630nm). We made colorimetric, clinical, and histological assessments with increasing doses of those lights on healthy volunteers. Then, we compared these irradiations to non-exposed and UVB exposed skin. Colorimetric and clinical assessments showed a clear dose-effect with the 415nm irradiation, in both skin type III and IV subjects, whereas the 630nm did not induce hyperpigmentation. When compared to UVB irradiation, the blue-violet light induced a significantly more pronounced hyperpigmentation that lasted up to 3 months. Histological examination showed a significant increase of keratinocyte necrosis and p53 with UVB, as compared to 415 and 630nm exposures. This article is protected by copyright. All rights reserved.
Article
BACKGROUND: Climates of the world are diverse and produce changes in skin integrity and functioning. Evidence on skin and its response to severe climates is limited, but information can be inferred from data characterizing skin under controlled climate conditions using noninvasive bioengineering techniques. METHODS: A literature search was conducted on the effects on major climate conditions on skin integrity and function. RESULTS: Exposure of murine skin to low humidity promotes a hyperproliferative and proinflammatory response, which can be prevented with topical agents or occlusion. Transepidermal water loss (TEWL) and average skin temperature (Tsk ) is highly sensitive to climate or ambient temperature (Tambient ). High altitudes leave skin more susceptible to UV radiation and even brief exposures cause surface changes. Pollution can result external skin aging and may be a risk factor for exacerbation of dermatoses. CONCLUSION: Further research is needed to understand skin properties and functioning in harsh climates to provide insight into optimal skin care for individuals living in such conditions.
Article
It has been well known that habitual smoking accelerates premature skin ageing recognized as 'smoker's face'. However, the effect of smoking cessation on the appearance of skin has not been elucidated. The aim of this study was to evaluate objectively the effect of smoking cessation on the skin's appearance. The stratum corneum carbonyl protein level and skin colour of the cheek and the hand were measured. The change before and during the smoking cessation treatment (0, 2, 4, 8 and 12 weeks), and the success or failure in smoking cessation, was compared and examined. Eighty-four cases who had smoking cessation treatment were examined. The level of the stratum corneum carbonyl protein did not show any difference comparing before and after treatment for the smoking cessation success group and the failure group. The lightness of skin colour showed an upward tendency 4-12 weeks after starting the treatment in the success group and increased significantly compared with the failure group. The redness showed a significant decrease in comparison with before the treatment, and it also showed a significant decrease compared with the failure group. The yellowness did not show any clear tendency. Also, the haemoglobin showed a decreased tendency. Furthermore, multivariate statistical analysis showed a possibility that the lightness and haemoglobin could be changed by smoking cessation treatment. In conclusion, our study showed that an upward tendency of skin lightness was seen to correspond with a haemoglobin decrease accompanied by smoking cessation. If we can easily measure skin improvement as an effect of smoking cessation, it is thought to be a useful aid for smoking cessation support. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.
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BackgroundSunlight damages human skin, resulting in a wrinkled appearance. Human skin temperature, measured inside the dermis by a needle-type thermometer, can be increased up to about 40 °C in direct summer midday sunlight within 15–20 min, and this heat may contribute significantly to sun-induced skin damage. Recent studies suggest that heat as well as UV may play an important role in premature skin aging. However, our knowledge about the effects of heat or infrared light, which certainly increase the temperature of the skin and may possibly interfere with or enhance the damaging effects of UV, on the development of skin aging is limited.ObjectivesThis review provides an outline of the thermal effects on skin aging process in human skin.
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Cigarette smoking has been associated with significant morbidity affecting all systems of the body, including the integumentary system. We review the many dermatologic hazards of tobacco use. It is important to distinguish between the effects of tobacco smoke from effects of pure nicotine on the skin. All skin cells express several subtypes of the nicotinic class of acetylcholine receptors, including the α7 receptor. Many chronic dermatoses are affected by smoking either negatively or positively. Elucidation of positive associations with a particular disease can lead to improvement from smoking cessation, whereas inverse correlation may lead to development of a disease-specific treatment with nicotinergic agonists.
Article
the broad sense of ‘non-genetic’. The exposome, therefore, complements the genome by providing a comprehensive description of lifelong exposure history. Remaining focused on the element of application (to epidemiology) is a key to ensuring that the exposome is translated from concept to utility for better delineating the causes and prevention of human disease. At the time of the original proposal, it was recognized that whereas exquisite tools had been developed to sequence the human genome and to interrogate individual susceptibility through genome-wide association studies (GWAS), there was a relative paucity of comparable tools, or indeed investment, in relation to exposure assessment. Given that cancer and other chronic diseases develop predominantly from a combination of environmental exposures played out on a particular genetic background, the inability to measure one part of the gene:environment combination with anything approaching the precision of the other will stymie progress. This becomes particularly acute as epidemiology aims to tease out relatively modest effect sizes associated with specific environmental exposures. This commentary seeks to further define the exposome and to describe how its realisation may be achieved in epidemiological studies. The commentary focuses on cancer but many of the concepts are applicable to other chronic diseases.
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Modern society has reported a decline in sleep time in the recent decades. This reduction can increase the morbidity and mortality of several diseases and leads to an immunosuppressive state. The skin is the largest organ in the human body and collagen, its main component, has a key role in the structure and integrity of the organism. The entire sequence of events necessary during collagen formation can be affected by endogenous and exogenous factors. A variety of studies in the literature have shown that sleep plays a role in restoring immune system function and that changes in the immune response may affect collagen production. Several studies of prolonged sleep deprivation suggest a break in skin barrier function and mucous membranes. In fact, the reduction of sleep time affects the composition and integrity of various systems. Thus, we hypothesized that lack of sleep as well as other types of stress can impair skin integrity.