Transepidermal water loss, hydration, pH and elasticity of skin in atopic dermatitis and normal Thai subjects.

ABSTRACT

In order to obtain objective data on skin functions in patients with atopic dermatitis (AD), we studied, by means of measurement of transepidermal water loss (TEWL), skin surface hydration, pH, and elasticity of dry and normal skin at the dorsum and volar aspects of the forearms in patients with atopic dermatitis compared with normal subjects. Transepidermal water loss (TEWL), skin surface hydration, pH, and elasticity function were measured using Tewameter TM 210, Corneometer CM 820, Skin-pH-meter pH 900, and Cutometer SEM 575, respectively. Forty-one subjects, twenty-five atopic dermatitis patients with dry skin, sixteen atopic dermatitis patients without dry skin, and twenty normal subjects, were recruited in the study. Considering all skin sites together, no significant differences were found between the mean values of TEWL in the same sites, the dorsum and volar forearms, of subjects in each group of patients (p = 0.717, and p = 0.981, respectively). Statistically, there were significant differences between the mean values of skin surface hydration at the dorsum and volar forearms (p = 0.019 and p = 0.019, respectively) and skin pH at the dorsum and volar forearms (p = 0.036 and p = 0.043, respectively). Regarding the elasticity function of the dorsum, immediate recovery and biological elasticity were significant differences in each group of the patients (p = 0.048 and p = 0.019, respectively), meanwhile, the elasticity function of the volar forearms, immediate recovery, elasticity index, elastic recovery index, viscoelastic ratio and relative elastic recovery were significant differences (p = 0.014, p = 0.029, p < 0.001, p < 0.001 and p < 0.001, respectively). Therefore, further well-controlled studies, investigating the skin morphology of patients with atopic dermatitis, should be pursued to provide more targeted therapies and establish an optimal standard of care for all patients with atopic dermatitis.