Baseline transepidermal water loss (TEWL) as a prediction of susceptibility to sodium lauryl sulphate.

The rôle of different factors in the susceptibility of the skin to weak irritants was studied by means of multiple linear regression models. The skin of 37 healthy subjects was exposed to a solution of sodium lauryl sulphate of low molarity 2 x daily for 4 days. The condition of the skin was evaluated by transepidermal water loss (TEWL) measurements on the 1st day (before exposure, TEWL1) and on the 5th day of exposure (TEWL5), and by a visual scoring system. The TEWL5 value was strongly related to the TEWL1 value (R = 0.71). The influence of such factors as history of mucosal atopy, history of sensitivity to soap, dry skin, skin type, sex and age on the TEWL5 value was negligible. The baseline TEWL level (TEWL1) might be a reliable indication of an individual's susceptibility to weak irritants.