Barrier recovery and influence of irritant stimuli in skin treated with a moisturizing cream

Moisturizers are used daily by many people to alleviate symptoms of clinically and subjectively dry skin. Recent studies suggest that certain ingredients in creams may accelerate the recovery of a disrupted barrier and decrease the skin susceptibility to irritant stimuli. In the present single-blind study, a moisturizing cream was tested for its influence both on barrier recovery in surfuctant-damaged skin and on the susceptibility of normal skin to exposure to the irritant sodium lauryl sulphate (SLS). Parameters measured were transepidermal water loss (TEWL) and skin corneometer values, indicating degree of hydration. Treatment of surfactant-damaged skin with the test cream for 14 days promoted barrier recovery, as observed as a decrease in TEWL. Skin corneometer values also normalized more rapidly during the treatment. In normal skin, use or the test cream significantly reduced TFWL after 14 days of treatment, and irritant reactions to SLS were, significantly decreased. Skin corneometer values increased after only 1 application and remained elevated after 14 days. In conclusion, the accelerated rate of recovery of surfactant-damaged skin and the lower degree of SLS-induced irritation in normal skin treated with the test cream may be of clinical relevance in attempts to reduce contact dermatitis due to irritant stimuli.     

Skin physiological parameters confirm the therapeutic efficacy of pimecrolimus cream 1% in patients with mild-to-moderate atopic dermatitis

Abstract:  In this double-blind, within-patient vehicle-controlled study, patients with mild-to-moderate atopic dermatitis (AD) were treated for 3 weeks twice daily with pimecrolimus cream 1% on one forearm and with vehicle cream on the other forearm. Efficacy of treatment was assessed clinically using the Atopic Dermatitis Severity Index (ADSI), the Investigators Global Assessment (IGA) and the pruritus visual analogue scale. In parallel, blood microcirculation in the skin was measured as an objective parameter for skin inflammation. Skin hydration and transepidermal water loss (TEWL) were monitored as parameter relevant for the barrier function. Treatment with pimecrolimus cream 1% resulted in a quick and marked improvement of signs and symptoms of AD and a significant reduction of microcirculation from 33.90 to 15.55 AU ( P  < 0.0001). Skin hydration increased continually from 42.86 to 52.69 AU ( P  = 0.002) and TEWL decreased from 35.30 to 21.50 g/m²/h ( P  = 0.001), indicating restoration of skin barrier. At vehicle-treated sites changes of skin physiological parameters were less pronounced and observed only initially with later plateau or even reversal. At the end of the study, there were significant differences for all measured skin physiological parameters between pimecrolimus cream 1% and vehicle: microcirculation 12.15 AU ( P  = 0.004), skin hydration 7.12 AU ( P  = 0.002), TEWL 11.38 g/m²/h ( P  = 0.004). Non-invasive evaluation of microcirculation and barrier functionality thus represent a valuable tool for the objective assessment of treatment response to pimecrolimus cream 1%.     

Evaluation of out–in skin transparency using a colorimeter and food dye in patients with atopic dermatitis

Background  Atopic dermatitis is a disease of skin barrier dysfunction and outside stimuli can cross the skin barrier.
Objectives  To examine a new method for evaluating the outside to inside skin transparency with a colorimeter and yellow dyes.
Methods  In study 1, a total of 28 volunteer subjects (24 normal and four with atopic dermatitis) participated. After provocation with yellow dye, the skin colour of all the subjects was measured using a colorimeter. The skin transparency index was calculated by the changes of the skin colour to yellow. Other variables of skin function, including transepidermal water loss (TEWL) and stratum corneum hydration, were also measured. In study 2, the skin transparency index was evaluated for a cohort of 38 patients with atopic dermatitis, 27 subjects with dry skin and 29 healthy controls.
Results  In study 1, the measurement of skin colour (b*) using tartrazine showed good results. There was a significant relationship between the skin transparency index with tartrazine and the atopic dermatitis score ( P  =   0·014). No other measurements of skin function, including the TEWL, were correlated. In study 2, the skin transparency index score obtained with tartrazine in the patients with atopic dermatitis was significantly higher than that of the controls and those with dry skin ( P  <   0·001 and P  =   0·022, respectively). However, the TEWL in patients with atopic dermatitis was not significantly higher than that of patients with dry skin and the TEWL in subjects with dry skin was not higher than that of the controls.
Conclusions  This method, which used a colorimeter and food dye, is noninvasive, safe and reliable for the evaluation of out–in skin transparency and can demonstrate the characteristic dysfunction in the skin barrier in patients with atopic dermatitis.     

Stratum corneum integrity as a predictor for peristomal skin problems in ostomates

Background Peristomal skin problems are common, most often the result is disruption of the skin barrier and this may account for more than one in three visits to ostomy nurses. Therefore a specific assessment of individual risk factors relating to the skin barrier function would be of great interest. Methods Skin barrier integrity in ostomy patients with peristomal skin problems (PSP) was compared with that of ostomy patients with normal skin (controls) using transepidermal water loss (TEWL). Mechanical barrier disruption was determined by a tape stripping test and chemical barrier disruption [sodium lauryl sulphate (SLS) 0·25%]. Results Patients and controls had a highly significant increase in TEWL value in the peristomal area compared with nonperistomal contralateral abdominal skin (P < 0·0001 for both groups). The skin barrier of normal‐looking contralateral skin of ostomates was found to be borderline impaired in patients with PSP compared with those without. A linear association was seen between the number of tape strips removed and TEWL for both cases and controls. Tape stripping suggested that patients with PSP had less resilient skin (P = 0·002). A significant difference in TEWL value between cases and controls was also seen for the SLS patch test on the dorsal skin (P = 0·02). Conclusion Successive tape stripping, a situation analogous to the normal use of a pouching system, caused a higher degree of barrier damage more rapidly in patients with PSP, indicating an impaired mechanical quality of the barrier. The SLS exposure test suggested a generally increased susceptibility to irritant dermatitis as assessed by TEWL. Our findings suggest tape stripping and SLS testing may have a role as predictive tests to identify patients at risk of PSP.     

Olopatadine hydrochloride accelerates the recovery of skin barrier function in mice

BACKGROUND: The skin barrier function in patients with atopic dermatitis is disrupted and prolonged topical steroid therapy produces epidermal barrier disturbance. Olopatadine hydrochloride (olopatadine; Allelock; Kyowa Hakko Kogyo Co., Ltd, Shizuoka, Japan) is an antiallergic drug with histamine H(1) receptor antagonistic action. This drug alleviates skin inflammation and decreases the number of scratching episodes in a murine model of chronic contact dermatitis. OBJECTIVES: To investigate the effects of olopatadine and a steroid on the recovery of skin barrier function after barrier disruption in mice. METHODS: The skin barrier of the ears of mice was disrupted by tape stripping. The recovery of skin barrier function was monitored by measurement of transepidermal water loss (TEWL) after barrier disruption. Epidermal hyperplasia was induced by repeated tape stripping for 7 days. Olopatadine was administered orally once daily from 3 days before the first barrier disruption. Betamethasone 17-valerate (betamethasone) was applied topically once daily from 3 days before barrier disruption. RESULTS: Tape stripping led to a significant increase in TEWL. TEWL decreased with time after tape stripping and the skin barrier function recovered by over 60% within 9 h after tape stripping. The recovery of skin barrier in olopatadine-treated mice was significantly accelerated, compared with that in vehicle-treated mice. In contrast, the skin barrier recovery in mice treated with topical betamethasone was significantly delayed, compared with that in vehicle-treated mice. Combined treatment with olopatadine and betamethasone ameliorated the delay in barrier recovery induced by topical treatment with betamethasone. In addition, olopatadine significantly prevented the increase in epidermal thickness induced by prolonged barrier disruption. CONCLUSIONS: These results suggest that systemic administration of olopatadine accelerates the recovery of skin barrier function and ameliorates the adverse effects of topical steroids on skin barrier recovery.     

Skin susceptibility of atopic individuals

The relevance of the irritant skin reaction of individuals with an atopic history (atopic dermatitis, rhinoconjunctivitis or atopic asthma) to sodium lauryl sulfate (SLS), a widely used irritant, is still controversial. The aim of this study was to evaluate transepidermal water loss (TEWL) as an indicator of stratum corneum integrity, before and after SLS patch testing, in various groups of atopic individuals with and without atopic dermatitis. 95 volunteers were divided into 4 groups: (1) individuals with active atopic dermatitis; (2) individuals with a history of atopic dermatitis but without active skin lesions; (3) individuals with rhinoconjunctivitis or atopic asthma without any symptoms at the time of testing; (4) healthy individuals serving as controls. The volunteers were patch-tested at the unaffected volar side of the forearm with aqueous SLS 0.5% for 48 h. TEWL was measured before application and after removal of the patch. Individuals with active atopic dermatitis showed a significantly higher TEWL value after SLS and a tendency to a higher basal TEWL as compared to the 3 other groups. There were no significant differences in TEWL between individuals who were classified as atopic but without active dermatitis, individuals with rhinoconjunctivitis or atopic asthma and healthy controls, either at the basal or at the post-SLS measurement. Enhanced skin susceptibility is only present in individuals with active dermatitis. The skin susceptibility of atopic individuals might therefore be increased as soon as the skin becomes eczematous, suggesting a reduced epidermal integrity probably caused by the endogenous atopy and/or respiratory allergens. When interpreting the atopy score in relation to skin susceptibility, the actual condition of the skin should hence be taken into consideration.     

Skin barrier response to occlusion of healthy and irritated skin: Differences in trans‐epidermal water loss,erythema and stratum corneum lipids

Background. Occlusion of the skin is a risk factor for development of irritant contact dermatitis. Occlusion may, however, have a positive effect on skin healing. No consensus on the effect of occlusion has been reached. Objectives. To investigate skin barrier response to occlusion on intact and damaged skin. Methods. In study A, the response to occlusion (nitrile glove material) for either 8 hr daily for 7 days or for 72 consecutive hours, respectively, was determined and compared with that of non‐occluded skin. In study B, the response to occlusion of for 72 consecutive hours of skin that had been damaged by either sodium lauryl sulfate (SLS) or tape stripping, respectively, was determined and compared with that of to non‐occluded pre‐damaged skin. Skin barrier function was assessed by measurements of trans‐epidermal water loss (TEWL) and erythema. In study A, stratum corneum lipids were analysed. Results. Occlusion of healthy skin did not significantly influence skin barrier function, ceramide profile or the ceramide/cholesterol ratio. Occlusion of the skin after SLS irritation resulted in higher TEWL than in the control (P = 0.049). Occlusion of the skin after tape stripping resulted in lower TEWL than in control skin (P = 0.007). Conclusions. A week of occlusion did not significantly affect healthy skin, but was found to decrease healing of SLS‐damaged skin, and to improve healing of tape‐stripped skin.     

Ceramide analogue 14S24 selectively recovers perturbed human skin barrier

BACKGROUND: Topical ceramide application is an effective therapeutic approach in skin disorders with disturbed barrier function, including atopic dermatitis and psoriasis. OBJECTIVES: To evaluate ceramide analogue N-tetracosanoyl-(l)-serine tetradecyl ester (14S24) using a novel ex vivo model. METHODS: Freshly excised human skin was disrupted by lipid extraction, tape stripping and sodium lauryl sulphate (SLS) treatment. Barrier perturbation was evaluated by the measurement of transepidermal water loss (TEWL), skin hydration and the penetration of model compound, theophylline (TH), assessed by microdialysis. The effect of topical 5% 14S24 was compared with a commercial formulation containing a skin lipid mixture (LR) and control formulation with no skin lipids (L). RESULTS: Both LR and 14S24 produced significant recovery of TEWL and TH penetration in extracted and tape-stripped skin with 14S24 being significantly more effective. In SLS-treated skin, 14S24 decreased TEWL but not TH penetration; LR was inactive. L improved skin hydration but not barrier characteristics. Weak correlation between TEWL and TH penetration was observed in extracted and tape-stripped skin but not in SLS-treated skin. CONCLUSIONS: Cutaneous microdialysis can serve as a useful tool for the evaluation of skin barrier recovery by topical formulations ex vivo whereas TEWL may not be an appropriate measure of skin barrier function in such studies. The excellent barrier repair activity of 14S24 could be beneficial in skin disorders with ceramide deficiency.     

Epithelial barrier function and atopic diathesis in rosacea and perioral dermatitis

BACKGROUND: Rosacea and perioral dermatitis (PD) are common dermatoses, the aetiology and pathogenesis of which remain speculative. Objectives To investigate skin barrier function and features of atopy in both diseases. METHODS: We studied 75 patients with rosacea and 75 with PD. Transepidermal water loss (TEWL) was measured in three regions of the face (lateral chin, perinasal cheek, side of the nose) and the patients were assessed for atopy by clinical criteria, prick tests and specific IgE against a mixture of aeroallergens (CAP SX1). The control group consisted of 125 individuals with no history of rosacea, PD or active atopic disease. RESULTS: In patients with PD, TEWL was significantly increased (P < 0.001) at all measurement points in comparison with the rosacea and control groups. Significantly (P < 0.001) higher values were also found regarding history and clinical signs of an atopic diathesis, prick test reactivity and specific IgE against aeroallergens. CONCLUSIONS: PD is characterized by a skin barrier disorder of facial skin. It differs from rosacea in that it involves a significantly increased TEWL and features of an atopic diathesis. However, it remains disputed as to whether PD is an individual skin disease or a subtype of rosacea in atopic patients.     

Basal transepidermal water loss, skin thickness, skin blood flow and skin colour in relation to sodium-lauryl-sulphate- induced irritation in normal skin

The influence of basal transepidermal water loss (TEWL), skin thickness, blood flow and skin colour on susceptibility to sodium-lauryl-sulphate(SLS)-induced irritant contact dermatitis was studied in 70 healthy volunteers. SLS 0.5% was applied as a patch test. For assessment of basal values and skin response to SLS, bioengineering methods were used: TEWL was measured by an evaporimeter, skin thickness by ultrasound A-scan, blood flow by laser Doppler flowmetry, and skin colour by a colorimeter, using the L*a*b* system of the Commission Internationale de l'Eclairage (CIE). By use of multiple regression analysis, it was demonstrated that basal TEWL was substantially related to skin susceptibility to SLS, high basal TEWL predicting an increased susceptibility to SLS. Also increased light reflection from the skin, indicating a 'fair' skin, was found to be associated with increased susceptibility to SLS.     

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     

Baseline transepidermal water loss in patients with acute and healed irritant contact dermatitis

To examine the skin harrier function of patients with acute and healed irritant contact dermatitis ( n = 80) baseline transepidermal water loss (TEWL) was quantitatively measured using an evaporimeter. Healthy subjects served as controls ( n = 40). Test areas were the forearm and the thigh. A significant increase in TCVV'L was observed in the patients with acute and with healed irritant contact dermatitis (ICD) as compared LO healthy volunteers ( P ≤ 0.01). TEWL values in both test areas were com parable and markedly correlated ( p ≤ 0.01). with each other in every group. Thus, it is possible that basal TEWL depends more on the intrinsic skin barrier function of the subjects rather than the 2 anatomical regions examined. TEWL at the forearm with acme ICD was significantly higher ( P ≤ 0.01). than that of the group with healed ICD, but not for TCWL at the thigh suggesting that ICD may aggravate the barrier function of the adjacent involved skin. It is assumed, that increased basal TEWL in patients with ICD may relied a constitutional deviation of epidermal barrier function. This event seems to be comparable with the well-known symptom of atopic individuals. Using a detailed atopic scoring system in such a study may clarify the question of whether a proportion of patients with hand ICD may indeed be atopic individuals.     

Beneficial effects of a skin tolerance-tested moisturizing cream on the barrier function in experimentally-elicited irritant and allergic contact dermatitis

In experimentally-induced irritant (ICD) and allergic (ACD) contact dermatitis, an oil-in-water (o/w) cream was applied to investigate its effects on a disturbed barrier function compared to untreated physiological barrier repair. Transepidermal water loss (TEWL) measurements were performed. Before the start of the experiments, the skin tolerance of the cream was examined, revealing the non-irritating characteristics of the ingredients and the absence of any contact allergic patch test reaction. In the ICD study, sodium lauryl sulfate (SLS) patches were applied to the forearms of young female volunteers. Consequently, it was observed that repeated cream application (14 days, 2x/day) significantly improved the TEWL of SLS-damaged skin, leading to a complete recovery on day 15. In the ACD study, disruption of skin barrier function was obtained by a nickel-mediated contact allergy patch (CAP) test. The cream was then applied 2x/day for 4 consecutive days. Assessment of TEWL clearly showed that recovery of the disrupted skin significantly improved after cream application in comparison to untreated barrier repair.     

青鹏软膏对皮肤干燥志愿者及特应性皮炎样小鼠模型皮肤屏障功能的影响

目的 探讨青鹏软膏对皮肤屏障功能的影响及其可能机制.方法 招募12名小腿伸侧皮肤干燥的女性志愿者,青鹏软膏涂于右小腿伸侧(青鹏侧)、青鹏软膏基质涂于左小腿伸侧(基质侧),用药7d.分别于用药前、用药3d及用药7d测定皮肤屏障功能相关指标,如,经表皮失水量(TEWL)及角质层含水量.2,4-二硝基氟苯诱导小鼠背部产生特应性皮炎样改变,分别外用青鹏软膏基质(基质组),50％、75％、100％青鹏软膏治疗(50％、75％、100％青鹏组),每天2次,用药2周后,进行组织病理检查,背部皮褶厚度、TEWL的测定,免疫组化测定表皮丝聚蛋白,外皮蛋白及激肽释放酶7含量.结果 志愿者外用青鹏软膏及其基质,3d、7d后均较治疗前TEWL显著下降(青鹏侧f=2.651、3.615;基质侧t=2.996、3.586,均P＜0.05),含水量显著上升(青鹏侧f=9.029、13.842;基质侧f=5.830、11.299,均P＜ 0.001).青鹏侧及基质侧TEWL、含水量比较,差异无统计学意义(P＞0.05).从外观、皮褶厚度及组织病理看,基质组小鼠与模型组相比,皮炎程度差异不大,各青鹏组小鼠皮炎均有不同程度缓解.基质组、青鹏组TEWL均较模型组下降(P＜0.05),而基质组与青鹏组TEWL比较,差异无统计学意义(P＞0.05).基质组、青鹏组KLK7表达均较模型组下降(P＜0.05),但各治疗组间比较,差异无统计学意义(P＞0.05).结论 青鹏软膏基质有改善皮肤屏障功能的作用.     

Effect of an antioxidant (quercetin) on sodium-lauryl-sulfate-induced skin irritation

Quercetin is a bioflavonoid with antioxidant and anti-inflammatory activity. The purpose of this study was to examine the effect of quercetin on acute skin irritation, with special interest in the skin barrier function recovery. Acute irritant contact dermatitis was induced in 15 patients by 24-h occlusion of 2% sodium lauryl sulfate (SLS) (day (D) 1). The influence of application on SLS-irritated skin of topical quercetin for 5 consecutive Ds, compared to vehicle and controls, was studied. Parameters measured were transepidermal water loss (TEWL) and erythema index. Final measurements were taken on D 7 after a 1-D rest period. TEWL and the erythema index continued to rise 2 D after application of SLS and 1 D after treatment with quercetin, vehicle or controls. Both TEWL and erythema values at D 7 did not return to values before the SLS barrier disruption at all the test sites. Therefore, quercetin topically applied after induction of irritant contact dermatitis does not appear to increase the recovery of barrier function and erythema caused by SLS.     

Comparison of skin barrier function and sensory nerve electric current perception threshold between IgE-high extrinsic and IgE-normal intrinsic types of atopic dermatitis

Background  Two types of atopic dermatitis (AD) have been proposed, with different pathophysiological mechanisms underlying this seemingly heterogeneous disorder. The extrinsic type shows high IgE levels presumably as a consequence of skin barrier damage and feasible allergen permeation, whereas the intrinsic type exhibits normal IgE levels and is not mediated by allergen-specific IgE.
Objectives  To investigate the relationship between pruritus perception threshold and skin barrier function of patients with AD in a comparison between the extrinsic and intrinsic types.
Methods  Enrolled in this study were 32 patients with extrinsic AD, 17 with intrinsic AD and 24 healthy individuals. The barrier function of the stratum corneum was assessed by skin surface hydration and transepidermal water loss (TEWL), and pruritus perception was evaluated by the electric current perception threshold (CPT) of sensory nerves upon neuroselective transcutaneous electric stimulation.
Results  Skin surface hydration was significantly lower and TEWL was significantly higher in extrinsic AD than intrinsic AD or normal controls. Although there was no statistically significant difference in CPT among extrinsic AD, intrinsic AD and normal controls, CPT was significantly correlated with skin surface hydration and inversely with TEWL in intrinsic AD and normal controls, but not extrinsic AD. Finally, CPT was correlated with the visual analogue scale of itch in the nonlesional skin of patients with extrinsic but not intrinsic AD.
Conclusions  Patients with extrinsic AD have an impaired barrier, which increases the pre-existing pruritus but rather decreases sensitivity to external stimuli. In contrast, patients with intrinsic AD retain a normal barrier function and sensory reactivity to external pruritic stimuli.     

Improvement of skin barrier function during treatment of atopic dermatitis

Background: Active dermatitis causes a disturbance in skin barrier function. This can be evaluated by the measurement of transepidermal water loss (TEWL) and percutaneous absorption of hydrocortisone.Objective: The study objective was to evaluate changes in skin barrier function during treatment of atopic dermatitis.Methods: Nine patients with widespread atopic dermatitis were studied longitudinally by measuring the severity of the dermatitis and TEWL at intervals of 1 to 3 days. Percutaneous absorption of hydrocortisone was measured at entry and during treatment.Results: At entry, both TEWL and percutaneous absorption of hydrocortisone were elevated. Four to six days later, a significant decline was observed in both variables, indicating rapid improvement in skin barrier function. Individual changes in TEWL correlated with the changes in the systemic absorption of hydrocortisone.Conclusion: TEWL reflects changes in the systemic absorption of topical hydrocortisone during treatment of atopic dermatitis.     

Percutaneous penetration of sodium lauryl sulphate is increased in uninvolved skin of patients with atopic dermatitis compared with control subjects

BACKGROUND: Involved regions of the skin in patients with atopic dermatitis (AD) have been shown to have higher transepidermal water loss (TEWL), indicating a compromised skin barrier. Whether uninvolved skin also has diminished barrier characteristics is controversial. OBJECTIVES: To study the penetration of sodium lauryl sulphate (SLS) into uninvolved skin of patients with AD compared with the skin of control subjects. METHODS: Percutaneous penetration was assessed using the tape stripping technique on the stratum corneum (SC). Twenty patients with AD and 20 healthy subjects were exposed to 1% SLS for 4 h on the mid-volar forearm. After the end of exposure the SC was removed by adhesive tape. The amount of SLS was determined in each consecutive strip. Fick's second law of diffusion was used to deduce the diffusivity and the partition coefficient of SLS between water and the SC. RESULTS: The SC thickness was similar in both groups; however, the TEWL was higher in patients with AD compared with that of the control group (mean+/-SD 8.4+/-4.3 and 6.3+/-2.0 g m-2 h-1, respectively). There was a correlation between SC thickness and TEWL in control subjects but no correlation was found in patients with AD. The diffusivity of SLS through uninvolved AD skin was higher compared with normal skin (mean+/-SD 12.7+/-5.8x10(-9) and 6.2+/-3.0x10(-9) cm-2 h-1, respectively), while the partition coefficient between SC and water was lower (mean+/-SD 137+/-64 and 196+/-107, respectively). CONCLUSIONS: The results show a different penetration profile of SLS into the SC of patients with AD compared with control subjects. This indicates that even noninvolved skin in patients with AD has altered barrier characteristics, emphasizing the importance of skin protection and prevention of skin contact with chemicals.     

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.     

Treatment of cloth with a fabric softener ameliorates skin dryness

Dry skin is a condition characterized by impaired skin barrier function including atopic dermatitis and senile eczemas. Fabric softening chemicals (FSC) smoothens the surface of fabrics and thus decreases friction with the skin. Scientific evaluation of fabric softener on skin dryness is very limited. We evaluated the effectiveness and safety of FSC-treated T-shirts in subjects with dry skin. This is a randomized double-blind control study that included 40 male volunteers with apparent dry skin. Subjects were randomly divided into two groups: 20 men received 28 pieces of FSC-treated T-shirts wearing them for 4 weeks, and another 20 men received non-treated T-shirts. The effect of trial was evaluated by visual grading, subjective symptom, stratum corneum water content (SCWC), transepidermal water loss (TEWL), and dermoscopic skin surface analysis on days 0, 7, 14 and 28. A significant improvement of SCWC was observed in the skin of the shoulder (days 7-28) and lateral abdomen (day 14) wearing the treated T-shirts, but not in the non-treated T-shirts. In a stratified analysis of the low and high SCWC group, significant improvement was identified in the low SCWC groups but not in high SCWC groups. The visual grading of the shoulder improved significantly in the treated T-shirts group. No significant improvement was found in TEWL, dermoscopic analysis and subjective symptom in both groups. No remarkable side-effect was identified throughout this investigation. Addition of a fabric softener during clothes laundering is a potent preventive tool for dry skin.