Comparison of epidermal hydration and skin surface lipids in healthy individuals and in patients with atopic dermatitis

The water content of the stratum corneum and skin surface lipids are important factors in the appearance and function of the skin. A disruption of the balance between the two may lead to the clinical manifestation of dryness of skin in patients with atopic dermatitis.The aim of our study was to examine the so-called dry skin of patients with atopic dermatitis using objective parameters. We compared the epidermal hydration and the skin surface lipids, the so-called hydro-lipid film, of the clinically unaffected skin of patients suffering from atopic dermatitis with that of healthy subjects.A total of 48 patients of either gender were included in this retrospective case-control study. We used the Corneometer CM 820 (Courage+Khazaka Electronic GmbH, Cologne, Germany) and the Sebumeter SM 810 (Courage+Khazaka Electronic GmbH) as noninvasive measuring methods.The results showed marked decreases in the atopic dermatitis group for both the Corneometer and Sebumeter measuring methods.Our results show that the dry skin of patients with atopic dermatitis, as previously shown, is due not only to a decrease in skin moisture but also to a reduction of skin lipids. This finding gives rise to a new understanding of the condition, and therefore one should always speak of a hydro-lipid film.