Comparison of hydration, sebum and pH values in clinically normal skin of patients with atopic dermatitis and healthy controls

Conflict of interest: none declared. The water content of the stratum corneum and skin surface lipids forms a balance that is important for the appearance and function of the skin. An impaired balance may lead to the clinical manifestations known as ‘dry skin’, which is particularly seen in patients with atopic dermatitis (AD).1 This study was designed to compare epidermal hydration, skin surface lipid content and skin pH in healthy volunteers with that of the clinically normal skin of patients with AD. In total, 30 patients > 10 years old, with a diagnosis of atopic dermatitis based on the Rajka and Hanifin criteria with no other concomitant diseases, and 30 normal controls matched for age and gender were included in this case‐control study. This study was approved by the Ethics Committee of the Center for Research and Training in Skin Diseases and Leprosy. All patients gave written consent. Both the AD and control groups comprised 21 women and 9 men, with a mean age of 26.6 ± 9.7 years in the AD group and 25.4 ± 8.6 years in the control group. In the AD group, there were 6, 20 and 4 patients and in the control group 5, 21 and 4 subjects with Fitzpatrick skin types II, III, and IV, respectively.