Ethnic skin: overview of structure and function

The Potential of Exercise on Lifestyle and Skin Function: Narrative Review

BACKGROUND

The skin is an important organ of the human body and has moisturizing and barrier functions. Factors such as sunlight and lifestyle significantly affect these skin functions, with sunlight being extremely damaging. The effects of lifestyle habits such as smoking, diet, and sleep have been studied extensively. It has been found that smoking increases the risk of wrinkles, while excessive fat and sugar intake leads to skin aging. Lack of sleep and stress are also dangerous for the skin's barrier function. In recent years, the impact of exercise habits on skin function has been a focus of study. Regular exercise is associated with increased blood flow to the skin, elevated skin temperature, and improved skin moisture. Furthermore, it has been shown to improve skin structure and rejuvenate its appearance, possibly through promoting mitochondrial biosynthesis and affecting hormone secretion. Further research is needed to understand the effects of different amounts and content of exercise on the skin.

OBJECTIVE

This study aims to briefly summarize the relationship between lifestyle and skin function and the mechanisms that have been elucidated so far and introduce the expected effects of exercise on skin function.

METHODS

We conducted a review of the literature using PubMed and Google Scholar repositories for relevant literature published between 2000 and 2022 with the following keywords: exercise, skin, and life habits.

RESULTS

Exercise augments the total spectrum power density of cutaneous blood perfusion by a factor of approximately 8, and vasodilation demonstrates an enhancement of approximately 1.5-fold. Regular exercise can also mitigate age-related skin changes by promoting mitochondrial biosynthesis. However, not all exercise impacts are positive; for instance, swimming in chlorinated pools may harm the skin barrier function. Hence, the exercise environment should be considered for its potential effects on the skin.

CONCLUSIONS

This review demonstrates that exercise can potentially enhance skin function retention.

Whose Signals Are Being Amplified? Toward a More Equitable Clinical Psychophysiology

Research using psychophysiological methods holds great promise for refining clinical assessment, identifying risk factors, and informing treatment. Unfortunately, unique methodological features of existing approaches limit inclusive research participation and, consequently, generalizability. This brief overview and commentary provides a snapshot of the current state of representation in clinical psychophysiology, with a focus on the forms and consequences of ongoing exclusion of Black participants. We illustrate issues of inequity and exclusion that are unique to clinical psychophysiology, considering intersections among social constructions of Blackness and biased design of current technology used to measure electroencephalography, skin conductance, and other signals. We then highlight work by groups dedicated to quantifying and addressing these limitations. We discuss the need for reflection and input from a wider variety of stakeholders to develop and refine new technologies, given the risk of further widening disparities. Finally, we provide broad recommendations for clinical psychophysiology research.

Skin of color in dermatopathology: does color matter?

Skin of color (SoC) remains an understudied and under taught area of dermatology despite its rising importance. Race and ethnicity play a particularly important role in dermatology as skin pigmentation can affect the manifestation and presentation of many common dermatoses. With this review, we seek to review pertinent differences in SoC histology, as well as highlight the histopathology of conditions more common in SoC and address inherent bias that may affect accurate dermatopathology sign out.

Variations in genetics, biology, and phenotype of cutaneous disorders in skin of color - Part I: Genetic, biologic, and structural differences in skin of color

Skin of color (SOC) populations include those who identify as Black/African, Hispanic/Latinx, Asian/Pacific Islander, American Indian/Native Alaskan, Indigenous Australian, Middle Eastern, biracial/multiracial, or non-White; this list is far from exhaustive and may vary between and within cultures. Recent genetic and immunological studies have suggested that cutaneous inflammatory disorders (atopic dermatitis, psoriasis, and hidradenitis suppurativa) and malignancies (melanoma, basal cell carcinoma, and cutaneous T-cell lymphoma) may have variations in their immunophenotype among SOC. Additionally, there is growing recognition of the substantial role social determinants of health play in driving health inequalities in SOC communities. It is critically important to understand that social determinants of health often play a larger role than biologic or genetic factors attributed to "race" in health care outcomes. Herein, we describe the structural, genetic, and immunological variations and the potential implications of these variations in populations with SOC. This article underscores the importance of increasing the number of large, robust genetic studies of cutaneous disorders in SOC to create more targeted, effective therapies for this often underserved and understudied population. Part II of this CME will highlight the clinical differences in the phenotypic presentation of and the health disparities associated with the aforementioned cutaneous disorders in SOC.

Vulnerable Factors Affecting Urinary N-Methylformamide Concentration among Migrant Workers in Manufacturing Industries in Comparison with Native Workers in the Republic of Korea (2012-2019)

BACKGROUND

Occupational studies on N-N-dimethylformamide (DMF) exposure among migrant workers in Korea are scarce. We determined the urine concentration of N-methylformamide (NMF) among migrant workers with DMF exposure and compared the data with those of native workers.

METHODS

Data were collected from Workers' Special Health Examination and Work Environment Monitoring databases during 2014-2019. Workers aged ≥20 years were eligible to participate in the special health examination for DMF exposure. Urine concentrations of NMF were determined and compared between migrant and native workers. We also evaluated the factors affecting the difference in the urine concentration of NMF between the migrant and native workers. Multiple logistic regression was performed by adding confounders step by step.

RESULTS

Among 9259 subjects, 504 (5.2%) were migrant workers. The mean urinary concentration of NMF was 6.73 mg/L in migrant workers, which was significantly higher than that in native workers (2.06 mg/L, p < 0.001). The odds of a urine concentration of NMF > 30 mg/L were significantly higher in migrant workers than in native workers after adjusting for sex and age (odds ratio [OR] = 7.31, 95% confidence interval [CI] = 4.66-11.45). However, the odds between the native and migrant workers were not significantly different when fully adjusted for confounders (OR = 1.12, 95% CI = 0.65-1.94).

CONCLUSIONS

The excessive exposure to DMF among migrant workers was attributed not to differences in biological characteristics but to their work environment. Workers must have awareness of the use of protective equipment and knowledge of hazardous chemicals that they may be exposed to, especially at the workplace.

Fractional Q-Switched 1064 nm Laser for Treatment of Atrophic Scars in Asian Skin

Background and Objectives: Asian patients with Fitzpatrick skin type III–IV are a less studied subtype of patients in the medical literature. Q-Switched, 1064 nm neodymium-doped yttrium aluminum garnet (Nd: YAG) laser with a fractionated beam profile (QSF) is a new modality that was reported to be effective in the treatment of scars. This study aims to evaluate the efficacy and safety of QSF Nd: YAG laser in treating scars in Asian patients. Materials and Methods: A total of 29 Subjects were treated with 1064 nm QSF laser. Each patients had three treatments with a fractionated microlens array handpiece every 8 weeks). Efficacy of treatment was evaluated using the Goodman and Baron’s quantitative grading scale before and 3 months after the last treatment. Results: All 29 patients treated had significant improvement of acne scars according to Goodman and Baron’s Quantitative Global Acne Scarring Grading System. No side effect has been observed except some minor erythematous reactions in three patients. Conclusions: Our results confirm that the 1064 nm QSF Nd: YAG laser is a safe and effective technique for treating scars in Asians.

Season- and facial site-specific skin changes due to long-term mask wearing during the COVID-19 pandemic

Background

As people have regularly worn facial masks due to the coronavirus disease 2019 (COVID‐19) pandemic, mask‐wear‐related adverse effects on the skin have been recognized. The aim of this study was to explore skin changes, their seasonal variations in the general population caused by commonly used masks and a possible mechanism underlying negative effects of mask‐wearing.

Materials and methods

Eighteen Japanese females participated in the study during summer and winter in Japan. Skin characteristics were measured in the non‐mask‐wearing preauricular area and the mask‐wearing cheek and perioral areas.

Results

Trans‐epidermal water loss (TEWL) on the cheek area tended to be increased in winter, which was positively correlated with skin scaliness on the same area. Ceramide (CER) content and composition in the mask‐covered stratum corneum (SC) were slightly changed between summer and winter, and CER [NP]/[NS] ratio was negatively correlated with the TEWL on the perioral skin in winter. Skin hydration and sebum secretion were higher on the cheek compared to the perioral area in summer. Skin redness was particularly high on the cheek in winter.

Conclusion

Mask‐wear‐related skin changes were season‐ and facial site‐specific, and alterations in SC CER may play a role in barrier‐related skin problems caused by mask use.

Differences between perceived age and chronological age in women: A multi-ethnic and multi-centre study

Objective

Accuracy in assessing age from facial cues is important in social perception given reports of strong negative correlations between perceived age and assessments of health and attractiveness. In a multi‐ethnic and multi‐centre study, we previously documented similar patterns of female facial age assessments across ethnicities, influenced by gender and ethnicity of assessors.

Methods

Here we extend these findings by examining differences between estimated age from digital portraits and chronological age (Δ age) for 180 women from three age groups (20–34, 35–49, 50–66 years) and five ethnicities (36 images of each ethnicity, assessed for age on a continuous scale by 120 female and male raters of each ethnicity).

Results

Across ethnicities, Δ age was smallest in French assessors and largest in South African assessors. Numerically, French women were judged oldest and Chinese women youngest relative to chronological age. In younger women, Δ age was larger than in middle‐aged and older women. This effect was particularly evident when considering the interaction of women's age with assessor gender and ethnicity, independently and together, on Δ age.

Conclusion

Collectively, our findings suggest that accuracy in assessments of female age from digital portraits depends on the chronological age and ethnicity of the photographed women and the ethnicity and gender of the assessor. We discuss the findings concerning ethnic variation in skin pigmentation and visible signs of ageing and comment on implications for cosmetic science.

Chronic itch in African Americans: an unmet need

Chronic pruritus carries a significant burden of disease and is associated with a negative impact on quality of life. African Americans are disproportionately burdened by chronic pruritic disorders, including but not limited to atopic dermatitis, prurigo nodularis, inflammatory scalp dermatoses, pathologic scarring, and HIV-related dermatoses. Racial differences in skin structure and function may contribute to the pathogenesis of itch in African Americans. Itch perception and response to treatment in African Americans remain understudied and not well understood. As such, there is a large unmet need with regard to the knowledge and management of pruritus in African Americans. This review highlights notable differences in the epidemiology, pathophysiology, genetic predisposition, clinical presentation, and response to treatment for select pruritic skin conditions. By addressing itch as an unmet need in African Americans, we hope to improve patient outcomes and lessen disparities in dermatologic care.

Melanin has a Small Inhibitory Effect on Cutaneous Vitamin D Synthesis: A Comparison of Extreme Phenotypes

Epidemiology suggests that melanin inhibits cutaneous vitamin D₃ synthesis by UVR. Laboratory investigations assessing the impact of melanin on vitamin D production have produced contradictory results. We determined the effect of melanin on vitamin D₃ photosynthesis in healthy young volunteers (n = 102) of Fitzpatrick skin types II-VI (white to black). Participants, irrespective of skin type, were exposed to the same suberythemal UVR dose, to 85% body surface area, using solar simulated UVR or narrowband UVB (311 nm). This was repeated five times with intervals of 3-4 days between UVR exposures. Blood was taken before, during, and after the irradiation and assessed for serum 25-hydroxyvitamin D₃ (25[OH]D₃) as a marker of vitamin D₃ status. Linear UVR dose-dependent increases in 25(OH)D₃ were highly significant (P ≤ 7.7 x 10^-11). The ratios of regression slopes of the different skin type groups were compared, and only skin type II was significantly steeper than the other groups. Comparisons between extreme skin types II and VI showed melanin inhibition factors of approximately 1.3-1.4, depending on the UVR source. We conclude that the inhibitory effect of melanin on vitamin D₃ synthesis is small, compared with erythema, but that this difference may be sufficient to explain the epidemiological data.

Evolution of Biological Bandages as First Cover for Burn Patients

Significance: Cutaneous wound regeneration is vital to keep skin functions and for large wounds, to maintain human survival. In a deep burn, the ability of the skin to heal is compromised due to the damage of vasculature and resident cells, hindering a coordinated response in the regeneration process. Temporal skin substitutes used as first cover can play a major role in skin regeneration as they allow a rapid wound covering that, in turn, can significantly reduce infection risk, rate of secondary corrective surgeries, and indirectly hospitalization time and costs. Recent Advances: Skin was one of the first tissues to be bioengineered providing thus a skin equivalent; however, what is the current status subsequent to 40 years of tissue engineering? We review the classic paradigms of biological skin substitutes used as first cover and evaluate recent discoveries and clinical approaches adapted for burn injuries cover, with an emphasis on innovative cell-based approaches. Critical Issues: Cell-based first covers offer promising perspectives as they can have an active function in wound healing, such as faster healing minimizing scar formation and prepared wound bed for subsequent grafting. However, cell-based therapies encounter some limitations due to regulatory hurdles, as they are considered as "Advanced Therapy Medicinal Products," which imposes the same industry-destined good manufacturing practices as for pharmaceutical products and biological drug development. Future Directions: Further improvements in clinical outcome can be expected principally with the use of cell-based therapies; however, hospital exemptions are necessary to assure accessibility to the patient and safety without hindering advances in therapies.

In vivo determination of the skin surface topography and biophysical properties of human hands: Effects of sex and hand dominance

BACKGROUND

The effect of hand dominance on the skin topography and parameters associated with skin health and aging is unknown.

METHODS

Healthy adult volunteers were recruited. The following four strata were enrolled: Group 1: male, right handed; Group 2: male, left handed; Group 3: female, right handed; and Group 4: female, left handed. The differences between groups on their surface evaluation of living skin (SELS) parameters were evaluated. These variables included (a) roughness (SER); (b) smoothness (SESM); (c) scaliness (SESC); and (d) wrinkles (SEW).

RESULTS

A total of twenty subjects were recruited, with five in each stratum. Significant differences between groups were found for SESC [F(7,31) = 2.742, P = .024, partial eta squared = 0.382] and SEW [F(7,31) = 3.705, P = .005, partial eta squared = 0.456]. An evaluation of the descriptive statistics revealed that males had a higher mean SESC value than females and a lower mean SEW value. Moreover, the dominant hand of both sexes had a higher mean SEW value than non-dominant hands.

CONCLUSIONS

Given the evidence of sex and handedness differences in wrinkle genesis and desquamation severity, these factors should be considered in the dermatological treatment and counseling of patients.

Aesthetic aspects of skin aging, prevention, and local treatment

Skin aging is a complex biologic process influenced by a combination of intrinsic and extrinsic factors. Aging skin shows wrinkles, uneven tone, loss of elasticity, and thinning. Skin health is considered one of the principal factors representing overall well-being and the perception of health in humans; therefore, anti-aging strategies to combat aging signs and dysfunction have been developed over the last decades. Understanding the mechanism behind skin aging is required for elucidation of the mechanism of action and, hence, the potential benefits of the claimed anti-aging products. In this review, preventive measurements, cosmetologic strategies, and photoprotection (systemic antioxidants, ultraviolet and filters), as well as the mechanisms of action and the effectiveness of topical pharmaceutical agents, such as antioxidants (vitamins, polyphenols, and flavonoids) and cell regulators (retinols, peptides, hormones, and botanicals), are presented.

Effect of Mild Hyperthermia on Transdermal Absorption of Nicotine from Patches

Application of heat (hyperthermic conditions) on skin is known to enhance drug transfer and facilitate skin penetration of molecules. The aim of this work was to study the effect of hyperthermia on the drug release and skin permeation from nicotine transdermal patches. The drug release and skin permeation were characterized by in vitro release test and in vitro permeation test. The temperature was maintained at 32 °C as control (simulating normal physiological skin temperature) and 42 °C as hyperthermia condition. The in vitro release test was carried out using USP apparatus 5-Paddle over disk method for a transdermal patch. Skin permeation study was carried out across porcine skin using the flow through cells (PermeGear, Inc.) with an active diffusion area of 0.94 cm². Mechanistic studies (parameters such as partition coefficient, TEWL and electrical resistivity) were also performed to understand the mechanisms involved in determining the influence of hyperthermia on drug delivery from transdermal patches of nicotine. The rate and extent of drug release from nicotine patch was not significantly different at two temperatures (Cumulative release after 12 h was 43.99 ± 3.29% at 32 °C and 53.70 ± 5.14% at 42 °C). Whereas, in case of in vitro permeation studies, the nicotine transdermal permeation flux for patch was threefold higher at 42 °C (100.1 ± 14.83 μg/cm²/h) than at 32 °C (33.3 ± 14.83 μg/cm²/h). The mechanistic studies revealed that the predominant mechanism of enhancement of drug permeation by hyperthermia condition is by the way of increasing the skin permeability. There is a potential concern of dumping of higher dose of nicotine via transdermal route.

Evaluating the role of small particle hyaluronic acid fillers using micro-droplet technique in the face, neck and hands: a retrospective chart review

Background

Loss of the viscoelastic properties of the skin is a primary sign of aging and contributes to the appearance of wrinkles. Hyaluronic acid (HA) fillers are one of the most commonly used treatments for age-related soft-tissue reduction and volume loss. Evidence is also emerging that HA fillers rejuvenate the skin.

Methods

A retrospective chart review was completed on 20 subjects treated with small particle HA (SP-HA), to investigate its effects on skin properties. Subjects having received three treatments in the face, neck, and/or hands were considered in the analyses. Skin hydration, trans-epidermal water loss (TEWL), and pH were assessed at baseline (injection #1), Week 4 (injection #2), Week 8 (injection #3), and Week 12 (follow-up).

Results

Treatment with SP-HA significantly improved hydration levels in the face, neck, and hands. Significant results were seen in the face following the first three treatments, with subjects moving up to the next hydration level (ie, hydration went from dry to moisturized) and by the second treatment in the neck and hands. TEWL scores on the face and neck remained within healthy values throughout all visits. At baseline, TEWL scores on the hands were within critical condition and after three injections they recuperated to healthy values, while pH values remained within the normal range throughout treatment.

Conclusion

A treatment regimen consisting of three SP-HA injections was safe and well tolerated. SP-HA use demonstrated a hydrating effect while positively impacting the skin’s ability to retain moisture.

Effects of Short-Term Moisturizer Application in Different Ethnic Skin Types: Noninvasive Assessment with Optical Coherence Tomography and Reflectance Confocal Microscopy

BACKGROUND/AIMS

Ethnic skin types are known to differ in their morphological and physiological features. Thus, treatment responses may vary among different races. We aimed to assess skin morphology of different ethnicities and to compare the effect of short-term moisturizer application using optical coherence tomography (OCT) and reflectance confocal microscopy (RCM).

METHODS

Thirty healthy female subjects of European, Asian and Black ethnicity at 30-45 years of age were included in the study. OCT and RCM imaging was performed on the cheek to compare morphology. Following the 2-week application of a moisturizer cream (Sebamed® lotion) on one forearm, imaging was performed on both forearms to assess and compare treatment responses.

RESULTS

Epidermal thickness and morphology of pores varied between the three ethnic groups, with Black subjects displaying the thickest epidermis and largest skin pores. On the treated forearm, OCT measurements revealed a significantly thicker epidermis in all groups as compared to the untreated forearm. Width of skin folds on the treated forearm was measured by RCM to be significantly lower in all ethnic groups as compared to the untreated forearm.

CONCLUSION

Different ethnic skin types showed variations in skin morphology and treatment response to short-term moisturizer application. OCT and RCM were useful methods for noninvasive, real-time, repeated assessment of ethnic skin.

Scalp simulation - A novel approach to site-specific biomechanical modeling of the skin

OBJECTIVES

This study aimed to determine the hardness of the human scalp in vivo in order to identify an appropriate scalp simulant, from a range of commercially available silicone materials, for force impact assessment. Site-dependent variation in scalp hardness, and the applicability of contemporary skin simulants to the scalp were also considered.

MATERIALS AND METHODS

A Shore A-type durometer was used to collected hardness data from the scalps of 30 human participants (five males and five females in each of the three age categories: 18-30, 31-40, 41-50) and four commercially available silicones (light, medium, and heavy-bodied PVS, and duplication silicone). One-sample t-tests were used to compare the mean hardness of simulants to that of the scalp. Site-dependent variation in the hardness of the scalp was assessed using a mixed-model repeated measures ANOVA.

RESULTS

Mean human scalp hardness derived from participants was 20.6 Durometer Units (DU; SD = 3.4). Analysis revealed only the medium-bodied PVS to be an acceptable scalp simulant when compared to the mean hardness of the human scalp (p = 0.869). Scalp hardness varied significantly anteroposteriorly (with an observable linear trend, p < 0.001), but not mediolaterally (p = 0.271). Comparisons of simulants to site-specific variation in scalp hardness anteroposteriorly found the medium-bodied PVS to be only suitable in the central region of the scalp (p = 0.391). In contrast, the duplication silicone (p = 0.074) and light-bodied PVS (p = 0.147) were only comparable to the posterior region.

CONCLUSIONS

Contemporary skin simulants fail to accurately represent the scalp in terms of hardness. There is strong support for the use of medium-bodied PVS as a scalp simulant. Human scalp hardness varies significantly anteroposteriorly, but not mediolaterally, corresponding to regional anatomical variation within the scalp. A number of materials were identified as potential simulants for different regions of the scalp when more site-specific simulant research is required.

The immunology of atopic dermatitis and its reversibility with broad-spectrum and targeted therapies

Atopic dermatitis (AD), the most common chronic inflammatory skin disease, is driven by both terminal keratinocyte differentiation defects and strong type 2 immune responses. In contrast to chronic plaque-type psoriasis, AD is now understood to be a much more heterogeneous disease, with additional activation of T_H22, T_H17/IL-23, and T_H1 cytokine pathways depending on the subtype of the disease. In this review we discuss our current understanding of the AD immune map in both patients with early-onset and those with chronic disease. Clinical studies with broad and targeted therapeutics have helped to elucidate the contribution of various immune axes to the disease phenotype. Importantly, immune activation extends well beyond lesional AD because nonlesional skin and the blood component harbor AD-specific inflammatory changes. For this reason, future therapeutics will need to focus on a systemic treatment approach, especially in patients with moderate-to-severe disease.

Assessment of skin conductance in African American and Non-African American participants in studies of conditioned fear

Skin conductance (SC) is a psychophysiological measure of sympathetic nervous system activity that is commonly used in research to assess conditioned fear responses. A portion of individuals evidence very low or unmeasurable SC levels (SCL) and/or response (SCR) during fear conditioning, which precludes the use of their SC data. The reason that some individuals do not produce measurable SCL and/or SCR is not clear; some early research suggested that race may be an influencing factor. In the current article, archival data from five fear conditioning samples collected from four different laboratories were examined to explore SCL and SCR magnitude in African American (AA) and non-African American (non-AA) participants. Across studies, the aggregate group difference for exclusion due to unmeasurable SCL or no measurable SCR to an unconditioned stimulus reflected a significant medium effect size (d = 0.54). Furthermore, 24.3% (range: 0-48.3%) of AA participants met SC exclusion criteria versus 14.3% (range: 4.3-24.2%) of non-AA participants. AA participants also displayed significantly lower SCL during habituation (d = 0.58). The low SC levels and responses in AA individuals and the consequent exclusion of their contributions to fear conditioning study results impacts the generalizability of findings across races. Given higher rates of posttraumatic stress disorder (PTSD) and chronic anxiety in AA individuals, it is important that AA individuals not be excluded from fear conditioning research, which informs the treatment of anxiety and PTSD. Examination of the basis of very low SCL and/or SCR is a potentially informative direction for future research.

The burden of cutaneous melanoma and status of preventive measures in Central and South America

RATIONALE AND OBJECTIVE

Very little is known about the burden of cutaneous melanoma in Central and South America, despite the existence of a reasonable amount of population-based data. We present data on melanoma incidence calculated in a standardized way for Central and South America, as well as an overview of primary and secondary prevention issues in the region.

METHODS

Cancer registry data on all incident cases reported in the different registries present in Central and South America were combined to provide registry-based country estimates of age-standardized, sex-specific cutaneous melanoma incidence overall, and by histological subtype and anatomical site. A literature search provided additional information.

RESULTS

Age-standardized incidence rates were between 1 and 5 per 100,000 and tended to be higher further away from the equator. Cutaneous melanomas of the acral type, mostly occurring on the lower limbs, are a distinguishing feature of melanoma in Central and South America in comparison with high-incidence areas. Several preventive measures, both primary and secondary, are in place, albeit largely without evaluation.

CONCLUSION

Due to incomplete registration and different registration practices, reliable and comparable data on melanoma were difficult to obtain; thus it is likely that the true burden of melanoma in Central and South America has been underestimated. The different characteristics of the cutaneous melanoma patient population in terms of anatomical site and histological type distribution imply a need for adapted primary and secondary prevention measures. The generally high ambient ultraviolet radiation levels require sufficient sun protection measures.

The reliability and validity of outcome measures for atopic dermatitis in patients with pigmented skin: A grey area

Background

Outcome measures for atopic dermatitis (AD) patients with pigmented skin have neither been developed nor validated.

Objective

To compare the reliability and validity of four common AD outcome measures in patients with various levels of skin darkness.

Method

The inter- and intra-rater reliability and construct validity of the EASI (Eczema Area and Severity Index), objective-SCORing Atopic Dermatitis (oSCORAD), Three Items Severity index (TIS) and Six Areas, Six Sites Atopic Dermatitis (SASSAD) were evaluated in 18 patients of various levels of skin darkness, using their full body photographs, by five trained clinicians.

Results

The inter-rater reliability intraclass coefficient (ICCs) and 95% confidence intervals were poor for highly pigmented patients: EASI -.054(-.200 to .657), oSCORAD -.089(-.206 to .598), TIS -.21(-.24 to .147), SASSAD -.071(-.200 to .631); fair for mildly pigmented patients: EASI .464(.140-.839), oSCORAD .588(.265-.89), TIS.524(.200-.865), SASSAD .41(.045-.775); and fair to good for non-pigmented patients: EASI .64(.330-.908), oSCORAD .586(.263-.889), TIS .403(.09-.809), SASSAD .667(.358-.916). Erythema likely contributed to the inter-rater variability. Construct validity had significant correlations across all measures in non-pigmented patients, but no correlations in highly pigmented patients.

Conclusion

AD outcome measures have poor reliability and validity in highly pigmented patients, with variations in erythema perception being a contributor.

Scar treatment variations by skin type

Patients and clinicians use skin color attributes such as color uniformity, color distribution, and texture to infer physiologic health status. Normalization of skin color, surface texture, and height are important treatment goals in the treatment of scars. Skin color, structure, and response to trauma, vary with ethnicity. The incidence of hypertrophic and keloid scar formation is influenced by these inherent skin attributes. Skin type influences the response to various modalities including laser therapy and surgical intervention, and skin differences must be considered in treatment planning to achieve optimal results.

The translational revolution and use of biologics in patients with inflammatory skin diseases

Psoriasis and atopic dermatitis (AD) are common inflammatory skin diseases characterized by immune-mediated inflammation and abnormal keratinocyte differentiation. Although T-cell infiltration characterizes both diseases, T-cell polarization differs. Psoriasis is currently the best model for translational medicine because many targeted therapeutics have been developed and testing of targeted therapeutics has cemented psoriasis as IL-23/TH17 polarized. In patients with AD, although therapeutic development is approximately a decade behind that in patients with psoriasis, there is now active development and testing of targeted therapeutics against various immune axes (TH2, TH22, and IL-23/TH17). These clinical trials and subsequent molecular analyses using human samples will be able to clarify the relative roles of polar cytokines in patients with AD.

Male Circumcision and HIV Transmission; What Do We Know?

Male circumcision (MC) has been shown to be protective against heterosexual HIV transmission and is being explored in some parts of the world as a means of combating the epidemic. The World Health Organization (WHO) recommends that MC be considered as an important component of HIV prevention in high prevalence settings.

We review evidence that demonstrates that the inner foreskin is likely to be the main portal of entry for the HIV virus in males. Whether removal of the inner foreskin accounts for all the protection afforded by circumcision is yet to be established.

The proposed mechanisms of protection range from inherent immunohistological factors of foreskin such as difference in thickness of keratin layer and density of target cells for HIV between inner and outer foreskin to physiological mechanisms that follow male circumcision such as drying of secretions underneath foreskin after sexual intercourse, loss of microbiome that attract target cells to the genital mucosa and lack of priming the genital mucosa with less abundant sexual transmitted infections among circumcised men.

The aim of this review is to give an updated account on the mechanisms proposed so far on the demonstrated 50-70% protection from HIV transmission through heterosexual intercourse, by male circumcision.

International guidelines for the in vivo assessment of skin properties in non-clinical settings: Part 2. transepidermal water loss and skin hydration

BACKGROUND

There is an emerging perspective that it is not sufficient to just assess skin exposure to physical and chemical stressors in workplaces, but that it is also important to assess the condition, i.e. skin barrier function of the exposed skin at the time of exposure. The workplace environment, representing a non-clinical environment, can be highly variable and difficult to control, thereby presenting unique measurement challenges not typically encountered in clinical settings.

METHODS

An expert working group convened a workshop as part of the 5th International Conference on Occupational and Environmental Exposure of Skin to Chemicals (OEESC) to develop basic guidelines and best practices (based on existing clinical guidelines, published data, and own experiences) for the in vivo measurement of transepidermal water loss (TEWL) and skin hydration in non-clinical settings with specific reference to the workplace as a worst-case scenario.

RESULTS

Key elements of these guidelines are: (i) to minimize or recognize, to the extent feasible, the influences of relevant endogenous-, exogenous-, environmental- and measurement/instrumentation-related factors; (ii) to measure TEWL with a closed-chamber type instrument; (iii) report results as a difference or percent change (rather than absolute values); and (iv) accurately report any notable deviations from this guidelines.

CONCLUSION

It is anticipated that these guidelines will promote consistent data reporting, which will facilitate inter-comparison of study results.

Itch pathophysiology may differ among ethnic groups

The prevalence of itch is higher in individuals with darker skin types. In this paper, we review the systems involved in the physiology of itch and how they may differ across the races. Current data point out that the differences may be explained by barrier function, mast cell physiology, and itch receptor polymorphisms.

Sensitive skin: an overview

Sensitive skin is a condition of subjective cutaneous hyper-reactivity to environmental factors. Subjects experiencing this condition report exaggerated reactions when their skin is in contact with cosmetics, soaps and sun screens, and they often report worsening after exposure to dry and cold climate. Although no sign of irritation is commonly detected, itching, burning, stinging and a tight sensation are constantly present. Generally substances that are not commonly considered irritants are involved in this abnormal response.Sensitive skin and subjective irritation are widespread but still far from being completely defined and understood. A correlation between sensitive skin and constitutional anomalies and/or other triggering factors such as occupational skin diseases or chronic exposure to irritants has been hypothesized. Recent findings suggest that higher sensitivity can be due to different mechanisms. Hyper-reactors may have a thinner stratum corneum with a reduced corneocyte area causing a higher transcutaneous penetration of water-soluble chemicals. Alterations in vanilloid receptors and changes in neuronal transmission have been described. Monitoring skin parameters such as barrier function, proclivity to irritation, corneocyte size and sensorial transmission can also be useful to identify regional differences in skin sensitivity.

Atopic dermatitis in African American children: addressing unmet needs of a common disease

Recent published data suggest that the prevalence of atopic dermatitis (AD) in African American children is significantly higher than in Caucasians. There are certain characteristics in the presentation of AD in African Americans that seem to differ from those in other racial groups, but there is a paucity of information on this topic. In this review, we highlight the differences in pathophysiology, clinical presentation, and treatment of AD between African Americans and Caucasians. It is important for dermatologists to understand these differences in order to provide better care for African American children with AD.

Risk of squamous cell carcinoma of the skin in relation to IgE: a nested case-control study

BACKGROUND

Individuals diagnosed with nonmelanoma skin cancer have a high risk of developing a second skin cancer diagnosis. We assessed whether a marker of immune function related to atopic allergy, IgE, was associated with diagnosis of subsequent squamous cell carcinoma (SCC) of the skin in patients with a previous skin cancer enrolled in a skin cancer prevention trial.

METHODS

One hundred twelve individuals who developed an SCC (cases) were compared with 227 controls who did not develop SCC over the same followup period, matched on age, sex, and study center. Total, respiratory, and food-specific IgE were measured in the baseline or year one (prior to diagnosis) sera samples for each subject.

RESULTS

IgE levels were higher in cases with SCC than controls (comparing the highest quartile with the lowest, OR(total IgE) = 1.44; 95% CI: 0.73-2.85; OR(respiratory IgE) = 2.43; 95% CI: 1.16-5.06; OR(food IgE) = 2.53; 95% CI: 1.19-5.35). The association between respiratory IgE and subsequent skin cancer was strongest among individuals with a tendency to sunburn (OR(respiratory IgE) = 3.82; 95% CI: 1.05-13.88) compared with those with a tendency to tan (OR(respiratory IgE) = 0.95; 95% CI: 0.20-4.76). Among 25 subjects with repeat IgE measurements taken over several years, IgE levels were remarkably stable (interclass coefficient = 0.90 for total IgE).

CONCLUSION

These results indicate that allergy or allergy-associated IgE may be indicative of an immune phenotype that enhances risk of SCC, possibly via immune-associate inflammatory mediators.

IMPACT

Our results indicate that controlling allergy and IgE levels may be a new avenue of skin cancer prevention in susceptible populations, and implicate immune mechanisms in skin carcinogenesis.

Ethnicity and stratum corneum ceramides

BACKGROUND

The barrier function of the skin is dependent on an optimal composition of the stratum corneum lipids, exemplified by the altered lipid profile in patients with atopic eczema (AE). Differences in the global prevalence of AE point to the environment as an important factor in AE. Studies on filaggrin point to a genetic aspect in AE. The influence of environment and genes needs to be explored.

OBJECTIVES

To investigate possible differences in stratum corneum lipids between different healthy ethnicities living in the same environment.

METHODS

Healthy participants without any major skin diseases were enrolled in the study. Twenty-five participants of Asian origin (Asians), 18 of African origin (Africans) and 28 of Danish origin (white-skinned), all students at universities in the Copenhagen area of Denmark, had the ceramide profile of their stratum corneum examined using the cyanoacrylate method and analysed using high-performance thin layer chromatography.

RESULTS

For the ceramide/cholesterol ratio we found statistically significant differences between groups, with Asians having the highest ratio (P < 0·001 as compared with both white-skinned individuals and Africans), white-skinned individuals having intermediate values, and Africans having the lowest values. No statistically significant differences were found between any of the ceramide subgroups.

CONCLUSIONS

We found different ceramide/cholesterol ratios in comparable groups of different ethnicity, pointing to unknown genetic differences.

Skin wrinkles and rigidity in early postmenopausal women vary by race/ethnicity: baseline characteristics of the skin ancillary study of the KEEPS trial

OBJECTIVE

To characterize skin wrinkles and rigidity in recently menopausal women.

DESIGN

Baseline assessment of participants before randomization to study drug.

SETTING

Multicenter trial, university medical centers.

PATIENT(S)

Recently menopausal participants enrolled in the Kronos Early Estrogen Prevention Study (KEEPS).

INTERVENTION(S)

Skin wrinkles were assessed at 11 locations on the face and neck using the Lemperle wrinkle scale. Skin rigidity was assessed at the forehead and cheek using a durometer.

MAIN OUTCOME MEASURE(S)

Skin wrinkles and rigidity were compared among race/ethnic groups. Skin wrinkles and rigidity were correlated with age, time since menopause, weight, and body mass index (BMI).

RESULT(S)

In early menopausal women, wrinkles, but not skin rigidity, vary significantly among races, where black women have the lowest wrinkle scores. In white women, chronological age was significantly correlated with worsening skin wrinkles, but not with rigidity. Skin rigidity correlated with increasing length of time since menopause, however, only in the white subgroup. In the combined study group, increasing weight was associated with less skin wrinkling.

CONCLUSION(S)

Skin characteristics of recently menopausal women are not well studied. Ethnic differences in skin characteristics are widely accepted, but poorly described. In recently menopausal women not using hormone therapy (HT), significant racial differences in skin wrinkling and rigidity exist. Continued study of the KEEPS population will provide evidence of the effects of HT on the skin aging process in early menopausal women.

Assessing Fit of Nontraditional Assistive Technologies

There is a variety of brain-based interface methods which depend on measuring small changes in brain signals or properties. These methods have typically been used for nontraditional assistive technology applications. Non-traditional assistive technology is generally targeted for users with severe motor disabilities which may last long-term due to illness or injury or short-term due to situational disabilities. Control of a nontraditional assistive technology can vary widely across users depending upon many factors ranging from health to experience. Unfortunately, there is no systematic method for assessing usability of nontraditional assistive technologies to achieve the best control. The current methods to accommodate users through trial-and-error result in the loss of valuable time and resources as users sometimes have diminishing abilities or suffer from terminal illnesses. This work describes a methodology for objectively measuring an individual’s ability to control a specific nontraditional assistive technology, thus expediting the technology-fit process.

Percutaneous absorption and exposure assessment of pesticides

Dermal exposure to a diverse range of chemicals may result from various uses. In order to assess exposure and estimate potential risks, accurate quantitative data on absorption are required. Various factors will influence the final results and interpretations of studies designed to assess the ability of compounds to penetrate the skin. This overview will discuss skin penetration by pesticides, emphasizing key parameters to be considered from the perspective of exposure assessment.