The relationship between skin surface temperature, transepidermal water loss and electrical capacitance among workers in the fish processing industry: comparison with other occupations

A field study among workers in the fish processing industry (n = 143) was performed to obtain information about skin surface temperature, transepidermal water loss (TEWL), and electrical capacitance and their relationships during work. The skin temperature, TEWL and electrical capacitance were measured on the fingers, hands and forearms. A linear positive relation was found between the temperature and TEWL (in all measured areas), a linear negative relation between the temperature and capacitance (fingers and palms), and a linear negative relation between the capacitance and TEWL (fingers). The results on the fingers among workers in the fish processing industry were compared with results among metal workers (n = 52), cleaners (n = 30), gut cleaners (n = 25), nurses (n = 16), office workers with indoor climate syndrome (n = 20) and normal controls (n = 29). A linear positive relation was found between the respective temperature-TEWL values and a linear negative relation between the respective temperature-capacitance values in the various groups. Furthermore the slope of the temperature-TEWL relations was identical in all groups. Therefore, differences in TEWL levels (comparison at the same temperature) between the respective groups and controls and between the various groups might indicate damage to the skin barrier caused by contact with different irritants and chemicals. However, differences in environment-related variables in the various occupations might also affect TEWL levels. This field study demonstrates, from a practical point of view, how the skin temperature affects TEWL in the various occupations and, as a new point, how sensitive capacitance is to changes in skin temperature. Seasonal variation in TEWL and capacitance was demonstrated among workers in the fish processing industry, with a low TEWL and a high capacitance during summer when the workload is lower.     

Frictional properties of human skin: relation to age, sex and anatomical region, stratum corneum hydration and transepidermal water loss

Differences in the dynamic skin friction coefficients (mu) were investigated with respect to age, sex, and anatomical region. A total of 29 volunteers consisting of seven young females, seven old females, seven young males, and eight old males participated in the study. Measurements were obtained from II anatomical regions, namely, the forehead, upper arm, volar and dorsal forearm, postauricular, palm, abdomen, upper and lower back, thigh, and ankle. The friction data were compared with stratum corneum hydration and transepidermal water loss (TEWL). The dynamic friction coefficient did not vary significantly between age and sex groups but varied considerably among the anatomical regions of the body. The forehead and postauricular had the highest mu (0.34 +/- 0.02) while the abdomen had the lowest (0.12 +/- 0.01); the remaining regions had an average mu value of 0.21 +/- 0.01. Similarly, no sex differences were observed for TEWL and stratum corneum hydration. Capacitance was only significantly lower on the palms of the elderly. Regional differences showed a higher state of hydration on the forehead and postauricular as well as the upper arm, upper and lower back when compared with the volar forearm. TEWL was generally lower in the elderly on all anatomical regions except the postauricular and palm. A significant correlation was established between mu and capacitance for most regions. Between mu and TEWL significant correlation was observed only on the palm and thigh. These findings suggest that frictional properties of skin are dependent on more than water content or non-apparent sweating and the role of sebum secretion is suggested as one possible factor.     

Correlation of clinical features and skin barrier function in adolescent and adult patients with atopic dermatitis

BACKGROUND: Xerotic changes in atopic skin are considered to be related to a decrease in the water permeability barrier. Whether abnormal skin barrier function is the main cause of atopic dermatitis (AD) or a secondary change of the disease is still controversial. Noninvasive bioengineering methods, including the measurement of the transepidermal water loss (TEWL) and water capacitance, have been commonly used to evaluate skin barrier function. AIM: To evaluate the correlation between the clinical features of each evaluation site (severity of AD) and skin barrier function. METHODS: TEWL, capacitance, and pH were checked on five evaluation sites: postauricle, forearm, abdomen, thigh, and popliteal fossa. The subjects included 25 patients, both adolescents and adults, with AD and 25 age-matched normal controls. The clinical severity, from 0 (no clinical manifestation) to 3 (severe), was also scored for erythema, induration/papulation, lichenification, and xerosis on each evaluation site of the AD patients. RESULTS: Based on the data, we found that the clinical severity score was correlated with TEWL and capacitance in more than one-half of the evaluation sites. Erythema and induration/papulation showed a statistically significant correlation with TEWL in most cases (P < 0.05, four sites). Lichenification and xerosis showed a significant correlation with capacitance in most cases (P < 0.05, four sites). In most cases, severity scoring of the clinical features did not show a significant correlation with skin pH. The patients showed higher TEWL and lower capacitance than normal controls (P < 0.05, all five sites). CONCLUSIONS: The results of our study suggest that skin barrier function, measured by TEWL and capacitance, and clinical severity show a statistically significant correlation in patients with AD.     

Correlation between stinging, TEWL and capacitance

Background/aims: To study the correlation between stinging and skin barrier and to make the lactic acid stinging test much safer.
Methods: The modified lactic acid stinging test with 3% and/or 5% aqueous solution of lactic acid combined with transepidermal water loss (TEWL) and capacitance (CAP) was used. The amount of 50 µL-test material was applied on test areas, the skin of both sides nasolabial fold of 50 healthy subjects. Subjects assessed stinging basing on a 4-point scale at 0, 2.5, 5.0 and 8 min TEWL and CAP were measured at baseline and 8 min.
Results: The results show that the tendency of decrease in baseline CAP and increase in baseline TEWL are proportional with the increase of the sum of clinical scores (CS_S) . In 5% lactic acid test, negative correlation between changing ratio of TEWL (P_TEWL) and clinical score at 5 min (CS_5 min), and negative correlation between changing ratio of capacitance (P_CAP) and CS_5 min are registered.
Conclusion : Our data indicate that there is certain relationship between the degree of stinging and the skin barrier. The stinging test method modified by lower concentration aqueous lactic acid and the assessment combined with P_TEWL and P_CAP is suitable for Chinese to evaluate the skin susceptibility.     

The effect of prolonged drying on transepidermal water loss, capacitance and pH of human vulvar and forearm skin

The effect of prolonged drying on transepidermal water loss (TEWL), capacitance and pH of vulvar and forearm skin was studied in 15 healthy female volunteers. A desiccation chamber that absorbed water evaporating from the skin surface was applied to the forearm and labia majora skin daily for 4 days. Skin TEWL, capacitance and pH were measured daily and 4 days after removal of the desiccation chamber at the site of drying and at a symmetrical control site. Under desiccation, TEWL both of forearm and of vulvar skin showed an increase during the first days of drying, followed by a gradual decrease. After 4 days of drying, forearm TEWL was reduced to 91% of the control value, without reaching significance. Vulvar TEWL was significantly reduced to 80% of the control value. Although relative reduction of vulvar TEWL was higher than that of forearm TEWL, the absolute of value of vulvar TEWL after drying remained significantly higher than that of forearm TEWL. Skin capacitance significantly decreased under drying both in forearm and vulvar skin. Skin pH was significantly reduced by drying at the vulva, but not at the forearm. It is concluded that although changes in physiological parameters during drying seem to be more pronounced in vulvar than in forearm skin, differences suggest that the specific properties of vulvar skin are not explained by anatomically related occlusion alone.     

Electrical measurement of moisturizing effect on skin hydration and barrier function in psoriasis patients

Transepidermal water loss (TEWL) in psoriatic skin lesions seems to be related to the severity of the psoriasis, and the electrical capacitance and conductance of the skin are indicators of the hydration level of the stratum corneum. We compared the characteristics of these electrical measurements, in assessing the persistent effect of a moisturizing cream on skin hydration and barrier function in psoriasis patients. Seventeen Korean psoriasis patients were recruited. Their right leg was treated with the moisturizer twice daily for 6 weeks, while their left leg was used as the control site. For each patient, one psoriatic plaque on each leg was selected as the involved psoriatic lesion. Uninvolved psoriatic skin was regarded as the apparently healthy looking skin 4-5 cm away from the periphery of the psoriatic lesion. The TEWL, electrical capacitance and conductance were measured, in order to evaluate the barrier function and hydration level of the stratum corneum. The clinical and biophysical data for each patient were recorded at the start of the study and after 2, 4 and 6 weeks. The degree of skin dryness at the applied area improved progressively. The electrical capacitance at the treated psoriatic lesion increased significantly after 2 weeks, and this improvement was maintained during the entire study period. However, no noticeable change was observed in the electrical conductance. The TEWL showed an inverse pattern to that of the skin capacitance, decreasing during the study period. The skin capacitance and TEWL exhibited good correlation with the visual assessment of skin dryness, but the skin conductance did not. Our data suggest that electrical capacitance and TEWL may be useful in the evaluation of the effect of a moisturizer on the hydration status and barrier function of psoriatic skin.     

Skin physiological changes in employees in the fish processing industry immediately following work

In order to explain the complaints of dry skin after work among employees in the fish processing industry, we followed the skin blood flow (SBF), skin surface temperature, transepidermal water loss (TEWL) and electrical capacitance on the volar aspect of the 3rd finger in 10 fillet workers, where measurements were performed just at the end of a working day and during the next hour. The results were compared with 10 normal controls. During work, a low SBF, temperature and TEWL, and a high capacitance were found. After work, the SBF, temperature and TEWL increased to values above normal within 10-15 min, while the electrical capacitance decreased to subnormal values. A positive relation was demonstrated between skin temperature and TEWL, negative relations between temperature and capacitance, and between capacitance and TEWL. Our results in this field study confirm our clinical findings among workers in the fish processing industry: low occurrence of chapping and eczema during work and the development of dry skin after work.     

Transepidermal water loss and skin capacitance alterations among workers in an ultra-low humidity environment

No studies have been performed evaluating skin barrier alterations in humans exposed to ultra-low humidity (ULH) in spite of several lines of evidence from animal experiments suggesting that the skin barrier is altered on exposure to ULH. The objectives of this study were to assess barrier function changes in workers occupationally exposed to ULH (relative humidity 1.5%), and to evaluate whether the exposure duration shows a dose-response relationship with transepidermal water loss (TEWL) and skin capacitance. A total of 49 male workers exposed to ULH for 12 h per working day were classified into five subgroups based on their ULH exposure duration (<0.5 months, 0.5–1.0 month, 1.1–10.0 months, 10.1–20.0 months, and >20.0 months). A group of 12 age-matched male laboratory workers from a normal humidity environment were recruited as a control group. TEWL and skin capacitance were measured to evaluate their skin barrier function. TEWL measurements showed a significant decline (8.3±0.4 vs 10.0±0.4 g m^–2 h^–1, P<0.05) but no differences were found in skin capacitance (39.7±1.3 a.u. vs 45.0±2.4 a.u., P=0.68) between the whole ULH exposure group and the control group. Maximum decreases in TEWL and skin capacitance were seen in the subgroups exposed for <0.5 months and 0.5–1.0 month, respectively. Almost completely natural recovery occurred in skin capacitance after 20 months ULH exposure, in contrast to less than 90% recovery in TEWL. Three stages were defined according to the pattern of alterations in TEWL and skin capacitance in relation to ULH exposure duration. A positive association between TEWL and skin capacitance occurred in the control group and stage I but a negative correlation in stage II. No correlation was found in stage III. Our study demonstrated that workers exposed to a ULH environment could exhibit skin barrier alterations. Both TEWL and skin capacitance decreased within 2 weeks of ULH exposure. The maximum alterations in TEWL and skin capacitance occurred during 0.5–1.0 months and 2 weeks, respectively. TEWL recovered partially and more slowly than skin capacitance which recovered earlier and almost completely.     

Urea-containing moisturizers influence barrier properties of normal skin

Moisturizers are used in the treatment of dry skin, both clinically and in cosmetic products. In the present study the influence of different moisturizers on the normal skin barrier properties was evaluated by measuring transepidermal water loss (TEWL) and skin capacitance. In addition, the skin reactivity to a topically applied surfactant, sodium lauryl sulphate (SLS), following the use of the moisturizers was examined. The skin reaction was assessed visually and by measuring TEWL and superficial blood flow. Treatment with two urea-containing moisturizers for 10 and 20 days decreased TEWL. The irritant reactions after exposure to SLS were also significantly decreased after prior treatment for 20 days with the urea-containing moisturizers. In a double-blind vehicle-controlled part of the study, urea was found to decrease the skin susceptibility to SLS after only three applications. However, this decrease in skin reactivity was not preceded by a reduction in TEWL. Skin capacitance increased after three applications of urea-containing moisturizers and was still increased after 10 days, but not after 20 days of this treatment. Treatment for 20 days with two moisturizers without urea did not influence either TEWL or the susceptibility to irritation from SLS, but it increased the skin capacitance significantly. The mechanism underlying these changes is not known. The lower degree of SLS-induced irritation in the skin treated previously with urea-containing moisturizers may be of clinical relevance in reducing contact dermatitis from irritant stimuli. Received: 5 January 1995     

GentleYAG 1064nm激光治疗对小鼠皮肤屏障功能及弹性的影响

目的研究GentleYAG1064nm激光嫩肤治疗对皮肤屏障功能的影响。方法GentleYAG1064nm激光照射小鼠背部皮肤,每周1次,在激光照射前、首次照射后1周、连续3次照射后1周和连续4次照射后4周时检测皮肤经表皮失水(tramsepidermalwaterloss,TEWL)、含水量和皮肤弹性的变化。结果首次激光照射小鼠皮肤后1周时TEWL,皮肤含水量和皮肤弹性基本上较正常对照组无显著性改变(P>0.05);连续3次激光照射小鼠皮肤后1周时TEWL值和皮肤含水量仍较正常对照组无显著性改变(P>0.05),但是皮肤弹性较正常对照组有显著性改善(P<0.05);连续4次激光照射小鼠皮肤后4周时TEWL值和皮肤含水量仍较正常对照组无显著性改变(P>0.05),皮肤弹性较正常对照组有显著性改善(P<0.05),其值高于连续3次激光照射后1周时,但两者间差异无显著性(P>0.05);用动态冷却系统(dynamiccoolingdevice,DCD)组和不用DCD组的TEWL值、皮肤含水量和皮肤弹性值在各个时间点上均无显著性差异(P>0.05)。结论①单次GentleYAG1064nm激光照射小鼠皮肤对皮肤屏障功能无明显的损伤。②多次GentleYAG1064nm激光照射可以改善皮肤弹性,说明多次GentleYAG1064nm激光照射有显著的嫩肤效果。③使用DCD对激光嫩肤效果无明显的促进作用。     

The effect of topical virgin coconut oil on SCORAD index,transepidermal water loss,and skin capacitance in mild to moderate pediatric atopic dermatitis: a randomized,double‐blind,clinical trial

Atopic dermatitis (AD) is a chronic skin disease characterized by defects in the epidermal barrier function and cutaneous inflammation, in which transepidermal water loss (TEWL) is increased and the ability of the stratum corneum to hold water is impaired, causing decreased skin capacitance and hydration. This study investigated the effects of topical virgin coconut oil (VCO) and mineral oil, respectively, on SCORAD (SCORing of Atopic Dermatitis) index values, TEWL, and skin capacitance in pediatric patients with mild to moderate AD, using a randomized controlled trial design in which participants and investigators were blinded to the treatments allocated. Patients were evaluated at baseline, and at 2, 4, and 8 weeks. A total of 117 patients were included in the analysis. Mean SCORAD indices decreased from baseline by 68.23% in the VCO group and by 38.13% in the mineral oil group (P < 0.001). In the VCO group, 47% (28/59) of patients achieved moderate improvement and 46% (27/59) showed an excellent response. In the mineral oil group, 34% (20/58) of patients showed moderate improvement and 19% (11/58) achieved excellent improvement. The VCO group achieved a post‐treatment mean TEWL of 7.09 from a baseline mean of 26.68, whereas the mineral oil group demonstrated baseline and post‐treatment TEWL values of 24.12 and 13.55, respectively. In the VCO group, post‐treatment skin capacitance rose to 42.3 from a baseline mean of 32.0, whereas that in the mineral oil group increased to 37.49 from a baseline mean of 31.31. Thus, among pediatric patients with mild to moderate AD, topical application of VCO for eight weeks was superior to that of mineral oil based on clinical (SCORAD) and instrumental (TEWL, skin capacitance) assessments.     

Noninvasive bioengineering assessment of the skin barrier function in patients with chronic venous insufficiency

Background  Chronic venous insufficiency (CVI) comprises all symptoms caused by permanent venous and capillary hypertension. While the clinical manifestations of the disease have been well characterized, there is little knowledge on the skin barrier function in the affected patients. Objectives  The aim of the study was to assess noninvasively the barrier function in patients with CVI stage C2 and stage C4 according to the CEAP classification in comparison with healthy controls (stage C0). Methods  Thirty patients with CVI without concomitant diseases and 15 healthy, aged‐matched controls were recruited for the study. The skin barrier function was assessed by measuring transepidermal water loss (TEWL), capacitance and skin colour symmetrically on the calf, medial and lateral malleolus, posterior arch (arcus venosus) and volar forearm. Results  Compared with the forearm, there was a tendency for increased TEWL and significant reduction of capacitance on all measurement sites on the lower limb. Compared with the control group, the patients with CVI had significantly higher TEWL values on all measurement sites on the lower extremities while no difference in capacitance between patients and controls was observed. Conclusions  Changes in the epidermal barrier function in patients with CVI are readily detectable by bioengineering methods as early as stage C2 and are manifested by significantly increased TEWL. Our results suggest that the reduced stratum corneum hydration in patients with CVI is due to anatomical differences rather than venous disease. These findings may help better understand the factors contributing to disease progression and its complications.     

Instrumental and dermatologist evaluation of the effect of glycerine and urea on dry skin in atopic dermatitis

Background/aims: Moisturising creams are useful treatment adjuncts in inflammatory dermatoses and have beneficial effects in the treatment of dry, scaly skin. The effects on dryness and skin permeability of a new moisturising cream with 20% glycerine was compared with its placebo and with a medicinally authorised cream with 4% urea (combined with 4% sodium chloride) in the treatment of dry skin.
Methods: Patients ( n =109) with atopic dermatitis were treated for 30 days with a moisturiser in a randomised, parallel and double-blind fashion. Transepidermal water loss (TEWL) and skin capacitance were assessed instrumentally, and changes in the dryness of the skin were assessed by the dermatologist.
Results: No difference in TEWL was found between glycerine treatment and its placebo, whereas a lower value was found in the urea-treated area compared to the glycerine-treated area. No difference in skin capacitance was found. The clinical assessment of dryness showed urea to be superior to glycerine in treating the condition.
Conclusions: Moisturising creams are different, not only with respect to composition but also with respect to their influence on skin as a barrier to water in patients with atopic dermatitis.     

Skin barrier, hydration, and pH of the skin of infants under 2 years of age

The goal of this study was to instrumentally evaluate the skin of healthy infants and to compare it to adult skin. A total of 70 infants, 45 girls and 25 boys, ages 8-24 months, and 30 healthy women were studied by means of transepidermal water loss (TEWL), capacitance, and pH measurements at two different skin sites, the volar forearm and the buttocks. No significant differences in TEWL were found between infants and adults, either on the buttocks or on the volar forearm. On the contrary, capacitance values were higher in infants. Their skin also appeared less acid than that of adults, with high statistical significance. No TEWL, capacitance, or pH variations were observed in infants according to sex and age. On the basis of the above data, the skin of infants 8-24 months of age shows functional signs of immaturity. This may lead to an increased permeability and a reduced capacity for defense against chemical and microbial aggression.     

轻中度痤疮患者皮肤生理参数特征

目的 探讨轻中度痤疮患者正常部位皮肤及炎性皮疹部位生理参数的特征。 方法 75例轻中度寻常痤疮受试者。每例受试者选择在48 h内出现,直径在2.0 ~ 5.0 mm之间的炎性皮疹作为靶皮疹。对靶皮疹及临近靶皮疹的正常部位皮肤进行经表皮失水率、表皮含水量及a*值的检测。洁面后即刻皮脂量、洁面后1 h皮脂量、皮脂饱和值在靶皮疹及双眉之间的额部进行检测并计算皮脂分泌速率。结果随着患者面部炎性丘疹数量的增加,痤疮患者正常部位皮肤的经表皮失水率、皮脂分泌速率显著增高（P < 0.05）。随着皮疹a*值的增高,皮疹部位经表皮失水率、皮脂分泌速率显著增高（P < 0.05）。皮疹部位经表皮失水率明显高于正常部位,而皮脂饱和值及皮脂分泌速率均显著低于正常部位（P < 0.05）。结论 痤疮患者炎性丘疹的严重程度与其面部皮肤屏障功能损伤及皮脂分泌速率增高有关。痤疮炎性丘疹部位与正常部位皮肤相比,皮肤屏障功能降低、皮脂分泌速率减小。     

Cutaneous barrier function after cold exposure in hairless mice: a model to demonstrate how cold interferes with barrier homeostasis among workers in the fish-processing industry

Dry skin and eczema only seldomly occur in workers in the Danish fish-processing industry (FPI) during work, when their fingers and palms have a low skin surface temperature, low transepidermal water loss (TEWL), and a high capacitance. However, shortly after work, when the skin temperature has become normal, TEWL levels increase to above normal, and capacitance decreases to below normal, followed by the development of dry skin or chapping, which subsequently revert to normal over a period of hours. These observations suggest that workers in the FPI may have a delect in skin barrier function, which is, however, masked by a low skin temperature, resulting in misleadingly low TEWL levels during work. To test this hypothesis, we disrupted the permeability barrier in hairless mice with topical acetone, and exposed the treated skin to ice for 3–5h. Although TEWL rates immediately after cold exposure were low, suggesting normal barrier recovery, TEWL increased to levels slightly above pre-cold exposure levels (i.e. levels just after the barrier was disrupted with acetone) when the skin temperature reverted to normal (≥ 15min). The changes in TEWL were paralleled by equivalent changes in percutaneous penetration of the electron-dense tracer lanthanum nitrate. This indicates that cold masks a defective barrier, and inhibits barrierrepair. After a few hours at ambient temperatures, normal barrier recovery was observed. Electron microscopy revealed empty or partially empty lamellar bodies during the first 30 min post-cold exposure. After 1 h the majority of nascent LBs displayed normal morphology. Moreover, histochemical studies showed a delayed reappearance of stratum corneum intercellular lipids following cold exposure. These results demonstrate that cold exposure prevents barrier recovery after acetone disruption, and provide an explanation for the occupatonal dermatosis observed in the fish-processing industry and related occupations.     

Biophysical parameters of skin: map of human face, regional, and age-related differences

The face showed anatomical variation on reaction to chemicals, which could be related to differences in biophysical specificities of the skin. The aim of this study was to establish a map of the face for 6 biophysical parameters.10 young human volunteers (24-34 years) and 10 old volunteers (66-83 years) were studied to prepare a map of the human face based on regional variations and age-related differences by measuring various biophysical parameters. 7 locations on the face, neck, and forearm were investigated. Skin blood flow, transepidermal water loss (TEWL), stratum corneum hydration (capacitance), temperature, pH, and sebum content of the skin surface were measured. In both groups, skin blood flow in the nose showed the highest value. Perioral and nasolabial areas showed the highest TEWL values. The neck showed the highest capacitance value. The highest skin temperature was detected in the neck in the young group and in the nasolabial area in the old group. The chin showed the most alkaline pH in both groups. Nasolabial area showed the highest sebum content in the young group, as did the chin in the old group. These baseline values provide a framework to build on for ascertaining disease and intervention-related effects.     

Changes in skin barrier function following long-term treatment with moisturizers, a randomized controlled trial

BACKGROUND: Moisturizers are commonly used by patients with dry skin conditions as well as people with healthy skin. Previous studies on short-term treatment have shown that moisturizers can weaken or strengthen skin barrier function and also influence skin barrier recovery. However, knowledge of the effects on skin barrier function of long-term treatment with moisturizers is still scarce. OBJECTIVES: To investigate the impact of long-term treatment with moisturizers on the barrier function of normal skin, as measured by transepidermal water loss (TEWL) and susceptibility to an irritant, and to relate those effects to the composition of the designed experimental moisturizers. METHODS: Volunteers (n = 78) were randomized into five groups. Each group treated one volar forearm for 7 weeks with one of the following preparations: (i) one of three simplified creams, containing only a few ingredients in order to minimize the complexity of the system; (ii) a lipid-free gel; (iii) one ordinary cream, containing 5% urea, which has previously been shown to decrease TEWL. The lipids in the simplified creams were either hydrocarbons or vegetable triglyceride oil, and one of them also contained 5% urea. After 7 weeks, treated and control forearms were exposed for 24 h to sodium lauryl sulfate (SLS) using a patch test. TEWL, blood flow and skin capacitance of both SLS-exposed and undamaged skin were evaluated 24 h after removal of patches. Additionally, a 24-h irritancy patch test of all test preparations was performed on 11 volunteers in order to check their possible acute irritancy potential. RESULTS: Changes were found in the barrier function of normal skin after 7 weeks of treatment with the test preparations. The simplified creams and the lipid-free gel increased TEWL and skin response to SLS, while the ordinary cream had the opposite effect. One of the simplified creams also decreased skin capacitance. All test preparations were shown to be nonirritant, both by short-term irritancy patch test and by measurement of blood flow after long-term treatment. CONCLUSIONS: Moisturizers influence the skin barrier function of normal skin, as measured by TEWL and susceptibility to SLS. Moreover, the effect on skin barrier function is determined by the composition of the moisturizer. The ingredients which influence the skin barrier function need to be identified, and the mechanism clarified at the molecular level.     

Amputee skin condition: occlusion,stratum corneum hydration and free amino acid levels

Patients with a prosthetic limb report negative skin effects, including irritation, rash and chaffing, which can lead to infection, discomfort and reduced wear time to significantly impact normal activities. The aims were to examine the epidermal integrity (transepidermal water loss, TEWL), stratum corneum (SC) hydration [moisture accumulation rate (MAT)], friction and biomechanical properties in active below the knee amputees and to determine the effects of an inert sock liner on skin condition. The liner reduced hydration, TEWL and friction and increased elasticity versus the amputee’s conventional skin care methods. Residual limb TEWL was increased and MAT was reduced versus the contralateral normal skin. In a second study, we hypothesized that complete occlusion would decrease free amino acids (FAA) and quantified them by high performance liquid chromatography in an adult volar forearm model. Occlusion with a water vapor impermeable wet dressing led to increased TEWL, erythema and dryness and reduced MAT versus normal skin, comparable to the results in the amputees. The FAA levels were significantly reduced for the occluded sites. The results suggest that residual limb occlusion in amputees may block the formation of FAA in the upper SC. Therapies based on replacement of water binding FAAs, may alleviate the consequences of long-term occlusion.