Differences In Skin Properties Research Articles

Performance of myotonometer in the assessment of skin involvement in systemic sclerosis.

A clinically practical tool to assess skin biomechanical properties rapidly and accurately is still lacking. Our aim was to examine the intra- and inter-observer reproducibility of a myotonometer for objective skin property assessment in systemic sclerosis (SSc), comparing it with the modified Rodnan skin score (mRSS), and distinguishing patients from healthy controls. Thirty-four patients (21 limited and 13 diffuse SSc), and 31 age and gender-matched healthy controls were enrolled. Skin tone and stiffness were measured at four different anatomical sites (the forearm, hand, leg, and foot) using a myotonometer. The correlation between the mRSS and skin properties was assessed. Also, hand functionality was evaluated for possible correlations between the variables. The differences in skin properties between dcSSc and lcSSc patients, and healthy controls were assessed using variance analysis. Intra- and inter-examiner reproducibility were excellent (ICC = 0.70 to 0.98) for tone and stiffness except for non-dominant hand tone, which showed good reliability (ICC = 0.64 to 0.74). Stiffness and tone values of the hands, forearms, and feet significantly correlated with mRSS total score (r = 0.40 to 0.71, p < 0.05). Additionally, tone and stiffness of the hands and forearms moderately correlated with hand function (p < 0.05). Tone and stiffness values increased in patients with dcSSc compared to healthy controls, or patients with lcSSc, at the hands, forearms, and legs (p < 0.05). Our findings emphasize the potential utility of the myotonometer for assessing skin properties and differentiating SSc patients from controls, demonstrating its promise as a valuable clinical evaluation tool in this context. Key Points •The myotonometer displayed excellent intra- and inter-examiner reproducibility for assessing skin properties. •Skin tone and stiffness parameters well correlated with the mRSS scores. •The myotonometer can distinguish patients with diffuse cutaneous SSc from healthy controls.

Skin properties associated with skin tears in older adults: A case-control study

BackgroundThe world population is growing rapidly and skin problems such as skin tears (STs) are more common in aging skin due to changes in the epidermis and dermis. Identification of ageing related skin properties, which are risk factors for STs, is essential for the development of ST prevention protocols. ObjectiveThe aim of this study was to reveal the skin properties related to epidermal function and dermal associated with STs. Material and methodsA prospective case-control study was conducted with a sample of 36 older adults, 18 participants with ST and 18 participants without ST, in two elderly care centers. Tewameter TM 210 was used to measure transepidermal water loss, the Sebumeter SM810 was used to measure sebum, and Cutometer Dual MPA 580 was used to measure skin viscoelasticity (R0-R9). The differences of skin properties between groups were analyzed using the independent t-test and Mann-Whitney U test. ResultsThe case group had a mean age of 77,17 ± 9,7 and the control group had a mean age of 75,33 ± 6,8. It was determined that there were more ecchymosis (p < 0.000), hematoma (p = 0.008), and ST history (p = 0.001) in the case group. Older adults in the case group were more frail than the control group (p = 0.044). Regarding the score of the skin properties, the case group showed that the TEWL levels of the older adults in the case group were lower (p = 0.031) compared to the control groups. There was a significant difference between the groups and R0, R2, R5, and R7. While R0 was higher in the case group, R2, R5, and R7 were lower than the control group. ConclusionOlder adults with ST showed differences in skin properties compared to those without ST, especially transepidermal water loss, and viscoelasticity (R0, R2, R5, R7). The results of this study suggest that some changes in skin properties may be a risk factor for STs.

Sex-related differences in response to zinc pyrithione shampoo vs. non-anti-dandruff shampoo.

Sex-related differences in skin properties may be expected to impact dandruff formation and treatment. A meta-analysis approach was undertaken to investigate potential differences between males and females in response to zinc pyrithione (ZnPT) treatment vs. non-anti-dandruff (AD) shampoo. A separate pooled statistical analysis of ceramide and total protein loss endpoints was also undertaken to assess potential sex-related differences in stratum corneum properties that might influence response to ZnPT vs. non-AD shampoo in subjects with dandruff. The meta-analysis approach included data from 17 half-head, double-blind, randomized studies (N=2088) undertaken in Asia to assess the effectiveness of 1% ZnPT shampoo and/or non-AD shampoo in reducing dandruff severity, as assessed by Total Weighted Head Score Adherent Flake (TWHS-AF) methodology. Treatment duration was 4weeks, with TWHS-AF measured at weekly intervals. Data from an additional three studies (N=143) conducted in Asia were included in the pooled analysis of ceramide levels and protein loss from scalp skin of subjects with dandruff. Response to 1% ZnPT vs. non-AD shampoo was greater in males than in females at all time points; after 4weeks, the between-treatment difference in TWHS-AF was -17.5 (95% confidence interval [CI] -19.5, -15.5) in males and -11.1 (-13.2, -8.9) in females. Sex-related differences were observed between males and females in response to both 1% ZnPT and non-AD shampoos. Males had a stronger response than females to treatment with 1% ZnPT shampoo, while dandruff decreased to a greater extent in females than in males when using non-AD shampoo. Statistically significant sex-related differences in ceramide levels and total protein loss were observed (both P<0.01). Ceramide levels were 0.76 times lower (95% CI 0.60, 0.97) in males than in females, while total protein loss was 1.4 times greater (95% CI 1.1, 1.9) in males than in females. Males show a greater response than females to 1% ZnPT shampoo, while females show a greater response than males to non-AD shampoo. These findings may in part be explained by the sex-related differences observed in stratum corneum properties, which may make males more prone to dandruff than females.

Race-related differences in tissue dielectric constant measured noninvasively at 300MHz in male and female skin at multiple sites and depths.

We hypothesized that reported race-related differences in skin properties cause skin and skin-to-fat water differences among races that are measureable by skin tissue dielectric constant (TDC) values that depend strongly on water content. Our first aim was to test this hypothesis. Also, since inter-side TDC ratios are used to assess edema and lymphedema, the second aim was to test if TDC ratios are race-dependent. The third aim was to determine the extent to which TDC depends on total body water (TBW) and fat (TBF). Tissue dielectric constant was measured to 1.5 or 5.0mm depths bilaterally on chest, forearm and ankle in 100 young (19-39years) adults with 10 male and 10 female per self-expressed race. Races were African-American, Asian, Asian-Indian, Caucasian and Hispanic groups. TBW and TBF were measured using bioimpedance. Tissue dielectric constant values decreased from chest to forearm to ankle (P<.001) independent of race with most values greater for males but with inter-arm TDC ratios independent of gender, site, depth, or race. For females, forearm TDC values differed among races (P<.01) with Asian and Asian-Indian values tending to be least. For males, chest TDC values differed among races (P<.01) mainly due to large African-American TDC values. For the composite group, TDC was strongly (P<.001) positively correlated with TBW and negatively correlated with TBF. Tissue dielectric constant dependence on race of the type herein uncovered should be considered in assessing skin hydration comparisons that include different race or ethnic subjects. Further, the demonstrated relationship between TDC and body composition should be considered as an important covariate. However, despite these variations, the inter-arm TDC ratio remains robust as a potential indicator of unilateral tissue water changes.

Treatment of standardised wounds with pure epidermal micrografts generated with an automated device

In this study, we analysed the effects of pure epidermal micrografts generated with an automated device in a standardised human wound model. Epidermal micrografts were harvested using an automated device. Micrografts were then transplanted onto split-skin donor sites. The target area was only partially covered with transplants to create an intra-individual control area. Wounds were evaluated by subjective assessment as well as measurements with combined laser and white light spectroscopy and cutometry. The epidermal graft sites remained completely stable, whereas control sites offered partially unstable and blistering areas. Statistically, no measurable difference in the speed of initial reepithelialisation could be shown. However, there was an increased pliability and softness of the treated areas that correlated with the subjective impression of both investigators and patients. There was a significantly higher relative haemoglobin concentration, measurable in treated and untreated areas at 4 weeks and 6 months. Cutometry showed no differences in skin properties between treated and untreated areas. This study shows an effect of epidermal micrografts in a standardised human wound model and supports the positive impact of keratinocytes on early wound healing as described in literature. Long-term effects of epidermal grafting deserve further studies.

Characterising the biophysical properties of normal and hyperkeratotic foot skin.

BackgroundPlantar foot skin exhibits unique biophysical properties that are distinct from skin on other areas of the body. This paper characterises, using non-invasive methods, the biophysical properties of foot skin in healthy and pathological states including xerosis, heel fissures, calluses and corns.MethodsNinety three people participated. Skin hydration, elasticity, collagen and elastin fibre organisation and surface texture was measured from plantar calluses, corns, fissured heel skin and xerotic heel skin. Previously published criteria were applied to classify the severity of each skin lesion and differences in the biophysical properties compared between each classification.ResultsCalluses, corns, xerotic heel skin and heel fissures had significantly lower levels of hydration; less elasticity and greater surface texture than unaffected skin sites (p < 0.01). Some evidence was found for a positive correlation between hydration and elasticity data (r ≤ 0.65) at hyperkeratotic sites. Significant differences in skin properties (with the exception of texture) were noted between different classifications of skin lesion.ConclusionsThis study provides benchmark data for healthy and different severities of pathological foot skin. These data have applications ranging from monitoring the quality of foot skin, to measuring the efficacy of therapeutic interventions.

Differences in Skin Properties of Korean Women at the Initial Aging Phase

Many studies on aging have focused on evaluating differences between older and younger people, but only a few have focused on differences in skin properties among subjects from the same age group according to their skin aging status. In this study, we evaluated the facial skin condition and life style factors in 110 Korean women aged 25 to 35 in an attempt to evaluate factors which may affect the skin aging status in the initial aging phase. The facial skin condition of 110 healthy Korean women was assessed over two successive 6-month periods, summer and winter. Using clinical assessments including aging, wrinkles and skin’s elasticity values, the subjects were divided into 7 groups. Then, various facial skin conditions and life style factors were examined between a severe aging group and mild aging group. In the severe aging group, the mean value pH was lower and the mean value of water content was slightly lower than that of women in the mild aging group. Also, the seasonal site variation in water content and sebum secretion level were significantly higher in the severe aging group than in the mild aging group. Topical sunscreen using percentage was not significantly different between the two groups. However, the number of cosmetic subject use was slightly higher in the mild aging group than in the severe aging group. The study suggested that there were several differences in skin characteristics between women in the severe aging group and in the mild aging group at the initial aging phase. Seasonal site variation between cheek and forehead was the most dominant differences. We also considered that life style factors such as cosmetic use could affect skin aging status.

Comparison of the skin biophysical parameters of Southeast Asia females: forehead–cheek and ethnic groups

Regional and ethnic (racial) differences in skin properties are well known. However, regional and racial studies are limited and have studied skin properties using an insufficient number of subjects and limited ethnic groups, except in the case of some recent studies. The aim of this study was (1) to compare the skin biophysical parameter among the large scale of Southeast Asia females group and (2) to compare skin properties of the forehead and cheek. We measured and compared seven skin biophysical parameters, such as skin hydration, sebum, skin pH, melanin index, erythema index, skin elasticity and transepidermal water loss (TEWL), of the forehead and cheek of a large population of Indonesian (n = 200), Vietnamese (n = 100) and Singaporean females (n = 97). At the point of site difference, there were significant differences in five biophysical parameters (skin hydration, skin pH, melanin index, erythema index and skin elasticity) in Indonesian females. In Vietnamese and Singaporean women, they were significant differences in five biophysical parameters (skin hydration, skin pH, melanin index, erythema index and TEWL). At the point of ethnic difference, the Indonesian women had the highest skin pH and melanin index between the different ethnic groups. Vietnamese women had the highest skin hydration and TEWL in the forehead, whereas Singaporean women had the highest skin elasticity. The skin biophysical parameters are different between the forehead and cheek among Southeast Asian females. It also reveals that the biophysical parameters are different in same racial group.

Comparative study of the hydration of the stratum corneum between four ethnic groups: influence of age

Several recent overviews have reported that significant work remains to be performed to understand and quantify the ethnic differences in skin properties. In this way, we have carried out a set of in vivo biophysical experiments on the skin of American women from different ethnic populations living in the same environment. Inter- and intraethnic skin micro relief results were already published, skin hydration differences are now reported here. The skin water content was evaluated taking advantage of the new skin capacitance imaging technique which allows to study stratum corneum hydration without suffering of the influence of the skin micro-relief and hair on the measurement. Three hundred and eleven American women from four ethnic groups were enrolled in this study. The investigation was performed during the summer season of 2004 on the major relatively distinct ethnic groups of Chicago, which is to say: African American, Chinese, Caucasian and Mexican. The hydration of the skin was investigated on the dorsal and ventral forearm sites as a function of ethnicity and age. Skin dryness is higher on sun exposed sites for lighter skin tones, such as in Chinese and Caucasian women, than on sites that are primarily out of the sun; while, no skin dryness differences are seen on either site for African American and Mexican women whose skin is darker. The skin dryness does not change as a function of ethnicity for the younger group for either the ventral and dorsal site of the forearm. With age, however, the dryness of the skin is higher for African American and Caucasian women than for the two other ethnic groups, with a higher percentage increase in Caucasian women. This study has revealed that the hydration of the skin is different according to ethnicity and that the age effects are influenced by ethnicity, suggesting anatomical or physiological property differences in ethnic skin. This study has also pointed out that the SkinChip seems to be a convenient and fast way to investigate both the micro relief as previously published and the dryness of the skin on a large number of subjects, and in this way will be very useful to improve our knowledge about skin of people from different ethnic groups and helping to develop specific products that are customized to all these populations.

Racial (ethnic) differences in skin properties: the objective data.

Racial (ethnic) differences in skin properties may explain racial disparities seen in dermatologic disorders and provide insight into appropriate differences in the management of these disorders. However, racial differences in skin have been minimally investigated by objective methods and the data are often contradictory. Objective methods studied include transepidermal water loss (TEWL), water content (WC), corneocyte variability, blood vessel reactivity, elastic recovery/extensibility, pH gradient, lipid content, surface microflora, microscopic evaluation of mast cell granules, and confocal microscopy. The majority of the evidence (six out of eight studies) indicates that TEWL is greater in Black skin compared with White skin. TEWL measurements of Asian skin are inconclusive as they have been found to be equal to Black skin and greater than Caucasian skin, equal to Caucasian skin, and less than all other ethnic groups in different studies. Racial differences in WC, as measured by resistance, capacitance, conductance and impedance, are also inconclusive as the data are contradictory. While the evidence regarding corneocyte desquamation is minimal, one clinically provocative observation is that Blacks have a 2.5 times greater spontaneous desquamation rate compared with Caucasians and Asians, possibly accounting for an increased frequency of xerosis seen clinically in Blacks. With regards to blood vessel reactivity, studies can not be compared to each other because each uses different vasoactive substances. However, each study, except for one study comparing Hispanics and Whites, and another comparing Japanese and German women, reveal some degree of racial variation in blood vessel reactivity. It has been demonstrated that the pH of Black skin is less than White skin; however, the studies that have demonstrated this have done so under different skin conditions and on different anatomic sites. Racial differences in lipid content are inconclusive. Additionally, there is insufficient and conflicting evidence to make conclusions regarding racial differences in skin biomechanics and skin microflora. Microscopic evaluation reveals that Black skin contains larger mast cell granules, and differences in stuctural properties and enzymes of mast cells compared with White skin, possibly accounting for differences in pruritus experienced by the individuals of these racial groups. There exists substantial evidence to support that Black skin has a higher TEWL, variable blood vessel reactivity, decreased skin surface pH, and larger mast cell granules compared with White skin. Although some deductions have been made about Asian and Hispanic skin, further evaluation needs to be done. Differences in WC, corneocyte desquamation, elastic recovery/extensibility, lipid content and skin microflora, although statistically significant, are inconclusive.

Population differences in skin structure and physiology and the susceptibility to irritant and allergic contact dermatitis: implications for skin safety testing and risk assessment.

Skin safety testing and risk assessment utilize a comparative toxicological approach whereby the inherent toxicity (irritation or sensitization) is related to exposure to determine the potential risk to a consumer population. However, consumers cover a broad spectrum of individual characteristics in terms of skin types and functions, as well as their basic habits and practices in use of consumer products. Thus, we try to use very conservative estimates for both inherent susceptibility to the toxic effect as well as the potential worst‐case exposures. While the inherent variation can be considerable even within a country, it is magnified even further when products are marketed globally. Questions have arisen, therefore, as to whether a skin safety testing approach conducted locally or regionally can adequately predict for adverse effects for the global consumer. A good deal of speculation exists that population differences are real and should mandate population‐specific safety testing prior to marketing products in certain regions of the world. In an attempt to address this question, this review has summarized extensive literature covering basic skin biology and function and susceptibility to irritant and allergic skin responses. Throughout this literature, there are individual studies demonstrating population differences in skin properties or in the responsiveness to chemical insult. Some of the research on this topic has pointed fairly convincingly to a demonstrable population difference. The best example of this is the tendency for blacks to have a lesser skin reactivity than Caucasians, likely due to a more impenetrable barrier. In contrast, the comparative data for Caucasians and Asians, for males and females, and for different age clusters are far less compelling. In terms of tendencies, there are little data to support any real difference in skin barrier function or in skin irritation responsiveness between Caucasians and Asians or between males and females. Comparing different age profiles, there does appear to be a slight decline in reactivity to irritants among the elderly (&gt; 65 years). Susceptibility to skin sensitization tends to be more related to exposure than any inherent susceptibility, though some data exist to suggest a slightly increased sensitivity in females versus males. On the basis of these data, standard procedures for skin safety testing and risk assessment can be considered relatively conservative. Most clinical skin safety studies are conducted in test populations that are comprised primarily of female Caucasians between the ages of 18 and 65 years. If anything, the skin reactivity “character” of this population cohort tends to skew toward the more reactive. This is not to say that population‐specific safety testing should not be done. There may be important reasons to pursue a population‐specific testing strategy in certain situations, perhaps due to regional, sex‐specific, or age‐specific marketing or to satisfy a regulatory or external relations need. However, there is yet no scientific justification to mandate such a strategy, based on our current knowledge of skin responsiveness and how it compares across diverse populations. There are clearly gaps in our understanding of population differences, particularly in regard to skin irritation that should guide future clinical research efforts. Side‐by‐side population testing for both acute and chronic skin irritation, more comparative testing of Asian subpopulations, testing for neurosensory irritation, and testing objective skin responses among hyperreactive subpopulations of multiple races are all areas in which additional research is needed. While current testing strategies have provided an excellent track record of success in providing safe and effective products to the world's consumers, results of such research will, in the future, help us to refine and further improve our skin testing and risk assessment capabilities.