Effect of long-term use of moisturizer on skin hydration, barrier functionand susceptibility to irritants

Moisturizers are often used in the prevention and treatment of irritant con tact dermatitis. The present study was to determine whether long-term daily use of a moisturizer on normal skin would affect skin barrier function, hy dration state, or susceptibility to sodium lauryl sulphate. Healthy volunte ers used a moisturizer on one forearm 3 times daily for 4 weeks, The other forearm served as a control, Afterwards both forearms were challenged with a patch-test of sodium lauryl sulphate, Skin barrier function was evaluated by measuring trans-epidermal water loss and skin hydration by measuring el ectrical capacitance. Electrical capacitance was significantly increased on the treated arm during the treatment period. After challenge with sodium l auryl sulphate, transepidermal mater loss was significantly higher on the a rm treated with moisturizer than on the control arm. The results suggest th at long-term treatment with moisturizers on normal skin may increase skin s usceptibility to irritants.