Determination of relevant endpoints to evaluate the in vivo barrier function in cutaneous health

This work aims to identify endpoints to evaluate the in vivo barrier function of the skin by noninvasive methods in healthy and atopic individuals, thus contributing to the consolidation of methodologies that can be employed in later studies of the action on skin health of different health products and food supplements. In this context, the cutaneous aggression induction model using sodium lauryl sulphate (SLS) was used, followed by evaluation of transepidermal water loss (TEWL) and vascular blood flow of the dermis by colorimetry and laser Doppler flowmetry (LDF), in a group of healthy volunteers (n = 15) and in a group with atopic dermatitis (n = 5). The healthy individuals presented a basal TEWL slightly superior to the atopic group. In skin without intervention, baseline values did not change, 24 hours after induction of irritation, in both groups (p <0.05). In the aggressed skin, in the same period, values presented a higher variation than that of the control zone (p <0.05), being greater in the atopic than in the healthy group. Results confirm that measurement of TEWL after SLS aggression allows a good assessement of skin barrier function in both healthy and atopic subjects and suggest that erythema may be a measure of support for the robustness of the results.