Stratum Corneum Lipids in Non-Lesional Atopic and Healthy Skin following Moisturizer Application: A Randomized Clinical Experiment

Introduction: It is an international standard to recommend patients with atopic dermatitis (AD) to use moisturizers; however, little is known about their effect on lipids in the stratum corneum (SC). Methods: In this randomized clinical experiment of 30 Caucasian participants (15 with AD and 15 healthy controls), the superficial SC lipid profile was assessed through tape stripping non-lesional skin following treatment thrice daily for seven days with a moisturizer, and subsequently compared with untreated skin. Results: No discernible disparity in superficial SC lipid quantity was evident between the AD group and the control group. However, the SC lipid composition diverged significantly, with the AD group exhibiting diminished levels of long-chain EO CERs (p = 0.024) and elevated levels of short-chain C34 CERs (p = 0.025) compared to healthy skin. Moisturizer application significantly reduced the total SC lipids and all lipid subgroups in both groups. Within the AD group, a non-significant inclination towards an augmentation in EO CERs (p = 0.053) and reduction in C34 CERs (p = 0.073) was observed. Conclusion: The recent identification of distinctions in SC lipid composition between AD and healthy skin was substantiated by our findings. Topical moisturizer application, despite reducing overall total lipids, indicated a potential tendency towards a healthier lipid constitution in AD skin.