Atopic xerosis: employment of noninvasive biophysical instrumentation for the functional analyses of the mildly abnormal stratum corneum and for the efficacy assessment of skin care products

The subtle dryness of the skin surrounding the lesions of atopic dermatitis (AD) is called atopic dry skin or atopic xerosis (AX). AX is more susceptible to the development of AD skin lesions under various environmental stimuli than the clinically normal skin of the people who have or have had or will have AD, which might be called normal atopic skin (NAS) that shows no functional differences as compared to the skin of normal individuals. Routine histopathologic studies of AX that involve the invasive procedures of biopsy are not so helpful in clarifying the underlying pathogenesis. Modern, noninvasive biophysical instrumentation provides rich and quantitative information about various functional aspects of skin. The stratum corneum (SC) of AX reveals not only decreased hydration but also mildly impaired barrier function demonstrable as an increase in transepidermal water loss, elevated pH values, and an increased turnover rate of the SC consisting of thick layers of smaller-sized corneocytes. These data suggest that AX is related to mildly increased epidermal proliferation as a result of the presence of subclinical cutaneous inflammation. Although AX skin does not display any impairment in the recovery of barrier function after physical skin irritation by tape-stripping, it produces a much more severe, long-lasting inflammatory response together with a delay in barrier repair after chemical irritation such as that induced by sodium lauryl sulphate. The SC of AX is biochemically characterized by reduction in the amounts of ceramides, especially ceramide I, sebum lipids, and water-soluble amino acids. None of these changes in SC functions are seen in NAS, which includes not only the normal-looking skin of AD patients long after regression of all active lesions but also of latent atopic skin such as neonates who later develop AD. This suggests that all of the observed functional as well as biochemical abnormalities of AX are a reflection of subclinical inflammation. The presence of the underlying inflammation in AX also differentiates it from senile xerosis. The mildly impaired SC functions of AX can be improved by daily repeated applications of effective moisturizers, i.e., corneotherapy, which is effective in preventing the exacerbating progression of AX to AD resulting from inadvertent scratching of the skin that facilitates the penetration of environmental allergens into the skin. The biophysical confirmation of such efficacy of moisturizers, including cosmetic bases on the mildly impaired barrier function and decreased water-holding capacity of the SC of AX, definitely substantiates the importance of skin care for the cosmetic skin problems that affect every individual in the cold and dry season ranging from late autumn to early spring.     

Facilitating facial retinization through barrier improvement

The utility of topical tretinoin as a treatment for improving the appearance of photodamaged skin is limited by irritation that occurs during the early phases of facial retinization. The observed side effects are consistent with stratum corneum barrier compromise. This paired double-blinded study was conducted to determine if preconditioning the skin with a barrier-enhancing cosmetic facial moisturizer before beginning tretinoin therapy and continuing moisturizer application during therapy would mitigate these side effects. Women with facial photodamage were recruited and randomly assigned to apply one cosmetic moisturizer to one side of the face and the other cosmetic moisturizer to the other side of the face twice daily for 10 weeks. One moisturizer contained a mixture of vitamins (niacinamide, panthenol, and tocopheryl acetate) to enhance stratum corneum barrier function, and the other moisturizer contained similar moisturizing ingredients but no vitamins. Daily full-face treatment with tretinoin cream 0.025% commenced 2 weeks into the study. Subjects' facial skin condition was monitored via investigator assessments, instrumental measurements, and subject self-assessments. The results show that improving stratum corneum barrier function before beginning topical tretinoin therapy and continuing use of a barrier-enhancing cosmetic moisturizer during therapy facilitates the early phase of facial retinization and augments the treatment response.     

Functional analyses of the skin surface of the areola mammae: comparison between healthy adult male and female subjects and between healthy individuals and patients with atopic dermatitis

Background Although the nipple and areola of the breast constitute a unique and prominent area on the chest, so far no study has been done on the functional properties of their skin surfaces. Objective To study the stratum corneum (SC) covering the areola using noninvasive methods. Methods Eighteen adult healthy subjects comprising nine men and nine women and 18 age‐ and sex‐matched patients with atopic dermatitis (AD), none of whom had visible skin lesions, participated in the study. Transepidermal water loss (TEWL), skin surface hydration and skin surface lipid levels were measured on the areola and adjacent breast skin. The size of the skin surface corneocytes of these skin regions was assessed. Results All the healthy subjects showed significantly higher TEWL accompanied by smaller sized corneocytes on the areola than on the adjacent breast skin. Only female subjects revealed a significantly higher skin surface hydration state together with significantly increased skin surface lipid levels on the areola than on the adjacent breast skin. These sex differences were observed even in patients with AD. Comparison between healthy individuals and the patients with AD demonstrated higher TEWL, decreased skin surface hydration state and lower skin surface lipid levels associated with smaller sized corneocytes in the areola in the patients with AD, especially in male patients. Conclusions In adults, the SC barrier function and SC water‐binding capacity of the areola were functionally poorer than in the adjacent skin, being covered by smaller sized corneocytes and lower amounts of skin surface lipids, especially in men and in patients with AD.     

Lipophilic and hydrophilic moisturizers show different actions on human skin as revealed by cryo scanning electron microscopy

To study the mode of action of moisturizers on human skin, hydrophilic moisturizers in water and neat lipophilic moisturizers were applied on excised skin for 24 h at 32 degrees C. Samples of the treated skin were subsequently visualized in a cryoscanning electron microscope. The stratum corneum (SC) appeared as a region of swollen corneocytes (the swollen region) sandwiched between two layers of relatively dry corneocytes (the upper and lower non-swelling regions respectively). Lipophilic moisturizers increased the water content of the SC, whereas hydrophilic moisturizers can also reduce the water content of the SC. When focusing on the effect of the moisturizers on the three different regions, it was observed that cells in the swelling region are most sensitive to the application of the moisturizers and that the change in SC thickness is most influenced by the change in the thickness of the swelling region. Summarizing, SC cells are not equally sensitive to moisturizer application: centrally located corneocytes are more sensitive than corneocytes in the upper and the lowest regions of the SC.     

Treatment with a barrier-strengthening moisturizing cream delays relapse of atopic dermatitis: a prospective and randomized controlled clinical trial

Background  Standard treatment of atopic dermatitis (AD) is based on topical glucocorticosteroids or calcineurin inhibitors to treat flares combined with moisturizer treatment to alleviate dry skin symptoms. Patients with AD have an abnormal skin barrier function, and strategies for reducing the risks for eczema would be to repair the barrier or prevent barrier dysfunction.
Objectives  The objective of this study was to explore the time to relapse of eczema during a 26-week maintenance treatment with a urea containing moisturizer compared to no treatment (neither medical nor non-medicated preparations) after successful clearing of atopic lesions. The moisturizer has previously been shown to improve skin barrier function.
Methods  Patients applied betamethasone valerate (0.1%) on eczematous lesions during a 3-week period. Those with cleared eczema entered a 26-week maintenance phase, applying the moisturizer or left the previously affected area untreated. Upon eczema relapse, patients were instructed to contact the clinic and to have the relapse confirmed by the investigator.
Results  Fifty-five patients entered the study and 44 patients were included in the maintenance phase (22 using moisturizer twice daily and 22 using no treatment). Median time to relapse for patients treated with moisturizer was > 180 days (duration of the study) compared with 30 days for the no-treatment group. Sixty-eight per cent of the patients treated with the moisturizer and 32% of the untreated patients remained free from eczema during the observation period.
Conclusions  Maintenance treatment with a barrier-improving urea moisturizer on previous eczematous areas reduced the risk of relapse to approximately one third of that of no treatment.     

The effect of aqueous cream BP on the skin barrier in volunteers with a previous history of atopic dermatitis

Background The emollient aqueous cream BP is frequently used for the treatment of atopic dermatitis (AD), yet it is associated with a high rate of adverse cutaneous reactions. It contains the harsh anionic surfactant sodium lauryl sulphate, a known negative environmental factor associated with the exacerbation of AD. Objectives To investigate the effect of aqueous cream BP on stratum corneum (SC) integrity and skin barrier function in volunteers with a predisposition to a defective skin barrier. Methods Thirteen volunteers with a previous history of AD (no symptoms for 6 months) applied aqueous cream BP twice daily to the volar side of one forearm for 4 weeks. The other forearm was left untreated as a control. Permeability barrier function and SC integrity were determined before and after treatment by measuring transepidermal water loss (TEWL) in conjunction with tape‐stripping. For comparison, 13 volunteers with current AD were recruited for assessment, without treatment, of SC integrity and skin barrier function at unaffected sites. Results Topical application of aqueous cream BP resulted in significant elevation of baseline TEWL and a concomitant decrease in SC integrity. Measurements made after no treatment in volunteers with current AD, at unaffected sites, suggest that application of aqueous cream BP negatively affects the skin barrier towards the damaged state associated with onset of flares of the disease. Conclusions Aqueous cream BP used as a leave‐on emollient caused severe damage to the skin barrier in volunteers with a previous history of AD. Aqueous cream BP should not be used as a leave‐on emollient in patients with AD.     

Squamometry as a screening method for the evaluation of hydrating products

Background/aims: Squamometry is a combination of sampling corneocytes by adhesive coated discs followed by colour measurements after staining the cells. In this study, the correlation between stratum corneum (SC) hydration and scaling was investigated using capacitance measurements and squamometry, respectively. Methods: Stratum corneum hydration and assessment of barrier function by transepidermal water loss (TEWL) measurements were carried out on different sites of left and right volar forearm skin of female volunteers (n=13; 24±3 years). D-Squame^® samples were taken on the same test spots. Results: Visual evaluation of the coloured samples by light microscopy and the development of a four-point-scale scoring system was found to be necessary to detect and minimise overestimation of chroma C* values. Capacitance measurements revealed neither significant differences between corresponding sites on left and right forearms no between different skin areas on the same forearm. Squamometric measurements, on the contrary, did not show any symmetry between corresponding test sites on both forearms or between different sites on one forearm. No correlation could be found between squamometric measurements and SC hydration values obtained at the same test sites. No skin barrier function impairment lays at the origin of this observation since TEWL values were found to be similar at all test sites in comparison to control skin. In a randomised single blind study, hydration and TEWL showed a significant improvement of 25% and 15%, respectively, after a 14-day application period of a moisturising cream. Although visual scoring of the coloured samples of both treated and untreated test spots revealed a good correlation with chroma C* values, the quantitative results found with squamometry were very doubtful. Conclusion: Squamometry with visual scoring can be proposed as a screening technique for SC hydration rather than a quantitative method to appreciate skin moisturisation.     

Ceramide-dominant barrier repair lipids alleviate childhood atopic dermatitis: changes in barrier function provide a sensitive indicator of disease activity

BACKGROUND: It is currently fashionable to consider atopic dermatitis (AD), like other inflammatory dermatoses, as immunologic in pathogenesis ("inside-outside" hypothesis). Accordingly, topical glucocorticoids and other immunosuppressive agents are mainstays of therapy, but the risk of toxicity from these agents is not insignificant, particularly in children. Alternatively, because stratum corneum (SC) permeability barrier function is also abnormal in AD, it has been hypothesized that the barrier abnormality could drive disease activity. Yet commonly used emollients and moisturizers do not correct the SC ceramide deficiency, the putative cause of the barrier abnormality. OBJECTIVES: We assessed the efficacy of a newly developed, ceramide-dominant, physiologic lipid-based emollient, when substituted for currently used moisturizers, in 24 children who were also receiving standard therapy for stubborn-to-recalcitrant AD. METHODS: All subjects continued prior therapy (eg, topical tacrolimus or corticosteroids), only substituting the barrier repair emollient for their prior moisturizer. Follow-up evaluations, which included severity scoring of atopic dermatitis (SCORAD) values and several biophysical measures of SC function, were performed every 3 weeks for 20 to 21 weeks. RESULTS: SCORAD values improved significantly in 22 of 24 patients by 3 weeks, with further progressive improvement in all patients between 6 and 20 or 21 weeks. Transepidermal water loss levels (TEWL), which were elevated over involved and uninvolved areas at entry, decreased in parallel with SCORAD scores and continued to decline even after SCORAD scores plateaued. Both SC integrity (cohesion) and hydration also improved slowly but significantly during therapy. Finally, the ultrastructure of the SC, treated with ceramide-dominant emollient, revealed extracellular lamellar membranes, which were largely absent in baseline SC samples. CONCLUSION: These studies suggest that (1) a ceramide-dominant, barrier repair emollient represents a safe, useful adjunct to the treatment of childhood AD and (2) TEWL is at least as sensitive an indicator of fluctuations in AD disease activity as are SCORAD values. These studies support the outside-inside hypothesis as a component of pathogenesis in AD and other inflammatory dermatoses that are accompanied by a barrier abnormality.     

Effect of long-term use of moisturizer on skin hydration, barrier function and susceptibility to irritants

Moisturizers are often used in the prevention and treatment of irritant contact dermatitis. The present study was to determine whether long-term daily use of a moisturizer on normal skin would affect skin barrier function, hydration state, or susceptibility to sodium lauryl sulphate. Healthy volunteers used a moisturizer on one forearm 3 times daily for 4 weeks. The other forearm served as a control. Afterwards both forearms were challenged with a patch-test of sodium lauryl sulphate. Skin barrier function was evaluated by measuring trans-epidermal water loss and skin hydration by measuring electrical capacitance. Electrical capacitance was significantly increased on the treated arm during the treatment period. After challenge with sodium lauryl sulphate, transepidermal water loss was significantly higher on the arm treated with moisturizer than on the control arm. The results suggest that long-term treatment with moisturizers on normal skin may increase skin susceptibility to irritants.     

Decreased hydration state of the stratum corneum and reduced amino acid content of the skin surface in patients with seasonal allergic rhinitis

Recent studies of the stratum corneum (SC) in patients with atopic dermatitis (AD) have disclosed various functional impairments even in clinically unaffected skin. However, it has not been clear whether the presence of atopic background itself has any influence on the function of the SC. In this study, we conducted functional studies of the SC in the mid-portion of the flexor surface of the forearm of 49 skin lesion-free patients with allergic rhinitis to Japanese cedar pollen (atopic respiratory disease; ARD) in early spring, their disease-active season, by comparing the findings obtained with those in 28 patients with AD and 57 age-matched healthy control subjects. The results showed that the patients with ARD had significantly lower skin surface hydration levels assessed by high-frequency conductometry than those of the healthy control subjects. These levels were, however, not as low as those noted in moderately or severely affected patients with AD. Moreover, by measuring the amounts of water-soluble amino acids contained in the superficial portions of the SC, we found that these are also decreased at a marginal level ( P  = 0.051) in patients with ARD compared with levels in healthy control subjects. In contrast, the water barrier function of the SC evaluated by measurements of transepidermal water loss in patients with ARD was not different from that of the healthy control subjects. These results suggest that, although their skin appears normal clinically, the SC of the patients with ARD has functional deficiency in water-holding capacity.     

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.     

Functional analysis of the stratum corneum of scalp skin: studies in patients with alopecia areata and androgenetic alopecia

Abstract Because of the presence of thick long hairs on the scalp, little information is available concerning the functional characteristics of the stratum corneum (SC) of scalp skin. We therefore conducted a functional study of the SC of lesional scalp skin of patients with alopecia areata and of patients with androgenetic alopecia. We compared the scalp with the cheek and the flexor surface of the forearm (volar forearm). The water barrier function of the scalp SC of both patient groups, in terms of transepidermal water loss (TEWL), was almost comparable to that of the volar forearm, and was far better than that of facial skin. However, hydration of the scalp skin surface, as evaluated by measurement of high-frequency conductance, was markedly higher than that of facial skin, and showed significantly higher values than the volar forearm. These characteristics seem to be dependent, at least to some extent, on the amount of sebum-derived skin surface lipids because these were abundant on the scalp skin. Moreover, removal of skin surface lipids led to a significant decrease in skin surface hydration. The superficial corneocytes, the size of which reflects the proliferative activity of the epidermis, were substantially smaller on the scalp than on the volar forearm but significantly larger than on the cheek. These findings suggest that the rate of turnover of the scalp epidermis is intermediate between that of the facial and volar forearm epidermis. We conclude that the SC of the scalp skin in humans is functionally distinct from that of the face and extremities. Received: 6 January 2000 / Revised: 11 August 2000 / Accepted: 25 September 2000     

Does massage postapplication improve moisturizer’s efficacy? A 2‐week regression study

Background Combining massage with moisturizer application is a popular technique in beauty spa sessions. The subjective positive psychological effects of massage with moisturizer application in hand and face beauty treatment are documented by many people attending spa sessions. The aim of this study was to objectively evaluate the effect of local effleurage massage as an external intervention on moisturizer efficacy. Methods In a regression‐type study of 2‐week, twice‐daily application followed by 1 week of regression, 13 female subjects applied “off the shelf” moisturizer twice daily on both forearms followed by 1 min superficial massage for one forearm randomized among subjects. The influence of massage after moisturizer application on skin barrier properties was evaluated by noninvasive measurements of transepidermal water loss (TEWL), skin capacitance, and skin elasticity at baseline, day 7, and day 14 during the treatment phase, and day 21 following a 1‐week regression period, in which no moisturizer and no massage were performed on forearms. Results The tested “off the shelf” moisturizer in both “massage” and “no‐massage” application protocols caused a comparable progressive improvement in skin hydration level and barrier permeability over the 2‐week treatment period, which was maintained during the 1‐week regression (no moisturizer) period. In addition, skin elasticity was similarly improved by both application protocols. Conclusion In this long‐term study, the daily performance of massage after moisturizer application was not an effective external intervention for enhancing moisturizer efficacy.     

Atomic force microscopy characterization of corneocytes: effect of moisturizer on their topology,rigidity, and friction

Background/purpose: Atomic force microscopy (AFM) is a novel technique for skin characterization. Objectives: To develop AFM tests for characterization of the outermost epidermis layer, corneocytes. As an example, the effect of moisturizer on the corneocyte properties is studied. Methods and materials: Topology, rigidity, and friction (between individual corneocytes and AFM probe) of the top layer of corneocytes were measured by means of Veeco DM3100 AFM. Quench^? moisturizing cream was applied daily on the forearm of five volunteers for a period of 9 days. The skin flakes were collected before and after the treatment using Cuderm tape strips. No additional treatment of flakes was performed before the measurements. Results: A protocol for the AFM study of corneocytes is developed. After the treatment, we observed overall smoothening of the corneocyte surface, an increase of friction, and a decrease of rigidity (the Young modulus). Conclusion: AFM can be used as a very sensitive tool for early detection of changes in corneocytes.     

Biophysical assessment of atopic dermatitis skin and effects of a moisturizer

BACKGROUND: The mechanisms of the skin barrier impairment in patients with atopic dermatitis (AD) are still unknown and need further studying. OBJECTIVE: We evaluated the skin of healthy subjects and of patients having atopic dermatitis with an instrument measuring electrical impedance and other noninvasive methods (transepidermal water loss, capacitance) and studied the effects of a new emollient [Proderm (Pro-Q in the USA)]. METHODS: After a 2-week washout period, we treated clinically noneczematous skin on the forearm of 24 patients with AD and assessed the effects with the noninvasive methods. 22 healthy subjects were used as controls. RESULTS: The findings indicate that barrier function and hydration, and certain patterns of electrical impedance of AD skin are abnormal compared with normal skin. Moreover, there was an increase in hydration in patients' skin after treatment and a reversal of certain impedance indices towards normal. CONCLUSIONS: Our findings demonstrate that the moisturizer we used changes some biophysical parameters when applied to atopic skin. In addition, a technique based on electrical impedance seems to give valuable information in atopic skin studies, especially the effects of moisturizers.     

富含亚油酸-神经酰胺的保湿剂在特应性皮炎鼠模型中的作用研究

目的：明确外用富含亚油酸-神经酰胺（Linoleic acid-ceramide, LA-Cer）的保湿剂对特应性皮炎（AD）鼠模型皮肤炎症和屏障的影响。方法：将18只BALB/c小鼠分为疾病组、治疗组和对照组,每组6只。疾病组以卡泊三醇（MC903）涂抹小鼠耳朵2周,诱导特应性皮炎模型;治疗组在诱导特应性皮炎的同时外用富含LA-Cer的保湿剂;对照组以无水乙醇外涂小鼠耳朵。比较各组间临床表型、组织病理、皮肤水含量的改变,通过实时荧光定量PCR检测炎症相关因子（TSLP,IL-4,IL-10,IL-1β,IL-33,IFNγ）的表达。结果：卡泊三醇诱导出较典型的小鼠AD模型。治疗组的鼠耳厚度（0.375±0.015）cm较疾病组（0.510±0.035）cm改善,治疗组皮肤含水量（22.500±2.081）au较疾病组（6.750±1.258）au高。与疾病组比较,治疗组皮损中炎症因子TSLP和IL-1β的表达含量明显降低。结论：外用富含LA-Cer的保湿剂可以减轻卡泊三醇诱导的特应性皮炎小鼠模型皮肤炎症,修护皮肤屏障。     

Establishment of an atopic dermatitis-like skin model in a hairless mouse by repeated elicitation of contact hypersensitivity that enables to conduct functional analyses of the stratum corneum with various non-invasive biophysical instruments

Background/aims: Pathogenesis of atopic dermatitis (AD) has been studied in animal models such as the NC/Nga mouse strain or Balb/C mice that are repeatedly treated with 2,4,6‐trinitro‐1‐chrolobenzene (TNCB). These mice exhibit features of chronic contact dermatitis, including an intensified early type skin reaction, increased number of mast cells and elevated serum IgE levels with a shift of cutaneous cytokine expression from a type 1 to type 2 profile. However, it is difficult to investigate the unique skin changes of AD such as dry skin, barrier dysfunction, and increased turnover of the stratum corneum (SC) in these animals with biophysical instruments because of the presence of their fur coats. In this study, we succeeded in establishing a mouse model of AD in hairless mice that are suitable for various functional analyses of the SC as well as for examining the immunological characteristics of human AD by treating TNCB‐contact sensitized hairless mice with 1% TNCB every other day for 36 days. Methods: In hairless animals treated with TNCB every 2 days for 36 days, we measured time courses of skin swelling induced by contact hypersensitivity reaction on days 0, 6, 20 and 36. During the time course, non‐invasive measurements for skin surface condition with biophysical instruments were conducted, and the area size and the rear surface villi of corneocytes obtained were measured. Also skin samples and blood samples were taken at each time point for histology and measurement of serum IgE level. Results: A gradual intensification of an early type contact hypersensitivity reaction was observed over the treatment period. These mice exhibited reduced SC hydration, heightened trans‐epidermal water loss, and increased skin thickness. These mice also showed a decrease in the surface area size of each corneocytes and marked villus formation on their rear surface. Histologically, there was an increase in the number of CD4 and CD8 positive T cells in the epidermis. Also observed was a marked increase in the number of dermal mast cells and eosinophils, which correlated with elevated serum IgE levels induced by TNCB treatments. Conclusions: From the results obtained we conclude that repeated treatments of TNCB‐sensitized hairless mice with TNCB provides a useful means by which to study the pathological characteristics of AD skin lesions as well as their immunological characteristics.     

特应性皮炎患儿与健康儿童皮肤屏障功能的对比

目的探讨特应性皮炎(AD)患儿与健康儿童皮肤屏障功能的差异。方法 0～7岁的AD患儿和健康儿童各60名,根据不同年龄段分成2组,0～2岁组和2～7岁组各30例。依次进行角质层含水量、pH值、经表皮水分丢失量(TEWL)的测量,使用SPSS13.0统计软件分析。结果 0～2岁、2～7岁AD患儿与健康儿童比较,角质层含水量除前臂无差异外,前额和颊前均明显低于健康对照组;皮肤表面pH值均明显高于健康对照组;0～2岁的AD患儿TEWL值除前臂无差异外,前额和颊前均明显高于健康对照组,而2～7岁AD患儿TEWL值均明显高于健康对照组。结论 AD患儿与健康儿童比较,皮肤屏障功能存在障碍。表现为角质层含水量、皮肤表面pH值、TEWL值有不同程度的差异。     

Normal recovery of the stratum corneum barrier function following damage induced by tape stripping in patients with atopic dermatitis

Patients with atopic dermatitis (AD) constantly inflict mechanical damage to their skin by scratching induced by pruritus. On excoriated lesions of the cheek we found exceedingly high levels of transepidermal water loss (TEWL) as compared to those in the normal skin of healthy subjects. However, it is not clear whether the skin of patients with AD also shows an abnormally slow recovery after mechanical damage. We compared the recovery of the barrier function of the stratum corneum (SC). after its complete removal by tape stripping, in patients with AD and age-matched healthy control subjects. On the normal-looking skin of the flexor forearm, we found no difference in the recovery process of the water barrier function of the SC between the two groups. This suggests that ability to reconstruct SC barrier function after mechanical damage is not impaired in AD patients.     

Niacinamide-containing facial moisturizer improves skin barrier and benefits subjects with rosacea

A growing body of literature suggests that some moisturizers can improve stratum corneum barrier function, as well as ameliorate dry skin. The clinical signs and symptoms of rosacea, which include increased facial skin dryness and sensitivity, suggest a possible role for such moisturizers as an adjuvant in the management of this condition. This randomized, investigator-blind, controlled observational study (N = 50) was designed to assess whether a niacinamide-containing facial moisturizer would improve the stratum corneum barrier and thus provide a clinical benefit to subjects with rosacea. Subjects with rosacea applied the test moisturizer to their face and to one forearm twice daily for 4 weeks. The other forearm remained untreated as a control. Barrier function on the forearms was assessed instrumentally and using a dimethyl sulfoxide (DMSO) chemical probe. Stratum corneum hydration also was measured instrumentally. The dermatologist investigator evaluated each subject's rosacea condition over the course of the study, and subjects self-assessed their facial skin condition at study end. Instruments provided objective measures of stratum corneum barrier function and hydration on the face.