Abstracts: Natural moisturizing factors in the stratum corneum II. Regeneration of NMF over time after soaking

Abstract

pp. 23–29 The detrimental effects of prolonged water exposure on skin are well known. Information on the effects of short‐term exposure, e.g. during bathing, showering, and hand washing, on Natural moisturizing factors (NMF) levels is limited. In an attempt to isolate the effects of soaking on the NMF, a time course for skin sample collection was devised in which adhesive tapes were applied 0.5 and 4 h after soaking of the treated arm. Significant decreases in NMF levels, quantified by high‐performance liquid chromatography analysis of serial tape strips, were observed 0.5 h after soaking, with a replacement of NMF occurring by the four‐hour mark. This replacement corresponds to a parallel rebound in skin pH also observed at these times. Stratum corneum (SC) hydration values, measured instrumentally as the rate of moisture accumulation (MAT), however, were depressed 0.5 h post‐soaking and remained low 4 h later. In addition, significant increases in skin pH were observed during the immediate post‐soak period. These findings suggest that short‐term exposure to water alone produces significant changes in the SC.