[Study of the correlation between transepidermal water loss and percutaneous penetration of steroid (author's...

Modifications of transepidermal water loss due to repeated topical applications of water/oil emulsion, salicylic acid and urea, with and without occlusion, were studied on the forearms of healthy volunteers. Percutaneous absorption of three different corticosteroids was evaluated by means of the bleaching test on each treated area. It was shown that only salicylic acid significantly increased transepidermal water loss. This increase was positively correlated with an increase in the percutaneous absorption of corticosteroids. Thus it seems that a comparative evaluation of the percutaneous absorption of topical treatments in normal and lesional skin may be obtained, in vivo in man, by nonaggressive comparative evaluation of transepidermal water loss.