Transepidermal water loss in dry and clinically normal skin in patients with atopic dermatitis.

To obtain data on the function of the epidermal barrier in patients with atopic dermatitis (AD) the transepidermal water loss (TEWL) was studied. Measurements were made on three body locations in two clinically well defined groups of patients with AD and in a control group. The TEWL was found to be increased both in dry non-eczematous skin and in clinically normal skin in patients with AD. The TEWL was highest in patients with dry skin. The result of the study may indicate a primary defect in the epidermal barrier: the stratum corneum.