Effect of moisturizers on skin susceptibility to irritants.

Moisturizers are used for the treatment of dry and irritated skin. The benefit of moisturizers when used on normal skin has recently been challenged, since an earlier study indicated that the increased hydration that follows long-term use of moisturizers on normal skin may facilitate penetration of irritants. The aim of the present study was to evaluate short-term use of 2 different moisturizers used on normal skin: cream A (high lipid content) and B (moderate/low lipid content). Nineteen healthy volunteers applied the moisturizers on the upper arm/forearm 3 times daily for 5 days, while the other upper arm/forearm served as symmetrical control. The day after moisturizer treatment was stopped the skin was challenged with a patch test of sodium lauryl sulphate. Skin reactions were evaluated by bioengineering measuring methods and clinical scoring. Skin response to sodium lauryl sulphate was increased on moisturizer-treated arms compared to controls for one of the moisturizer (cream A), while this was not statistically significant for the other moisturizer (cream B). Data confirm previous indications that some moisturizers when used on normal skin may increase skin susceptibility to irritants.