The Effects of Common Over-the-Counter Moisturizers on Skin Barrier Function: A Randomized, Observer-Blind, Within-Patient, Controlled Study.

Background: Moisturizers possibly improve atopic dermatitis (AD) by restoration of skin barrier, although some have detrimental effects.

Objective: The aim of the study was to estimate the effects of several routine moisturizers on barrier functions.

Methods: This is a randomized, forearm-controlled, observer-blind study. Patients older than 12 years with clear to moderate AD were randomized to 1 of 4 moisturizers (Cetaphil Cream, Aveeno Eczema Therapy Moisturizing Cream, CeraVe Moisturizing Cream, Vaseline) applied to nonlesional skin of 1 forearm and no moisturizer to the opposite forearm for 4 weeks. Transepidermal water loss (TEWL), capacitance, pH, and TEWL after tape stripping were evaluated at weeks 0 and 4. In addition, participants without AD underwent baseline measurements only.

Results: Twenty patients with AD completed the study. Baseline measurements between the AD group and 10 non-AD controls were similar. After the intervention (AD group), mean TEWL improved in the treated forearm and worsened in the untreated one, but the difference was not significant. There was no significant change in pH or in TEWL after tape stripping. Capacitance significantly improved in the moisturizer forearm. The study was underpowered as recruitment fell short.

Conclusions: The effects of moisturizers on nonlesional AD skin were small and need to be addressed when powering future studies. Broadening investigations beyond the classic barrier properties might be useful in future studies.