Study of cumulative irritant contact dermatitis in man utilizing open application on subclinically irritated skin.

We evaluated the effect of subclinical irritation on the cutaneous reaction elicited by cumulative short-term (30-min) application of sodium lauryl sulphate (SLS), by measuring transepidermal water loss (TEWL) and assigning visual scores. 11 healthy adult volunteers, free of skin disease and with no history of atopic dermatitis, were treated with SLS solution (1%, 2%, 5%, 7.5%). On a Monday, we applied 80 microliters of 1% SLS solution and deionized water (control), using large aluminium chambers with filter paper discs, for 30 min. We measured TEWL values 2 x before and after patch application of control and 1% SLS solution, and then applied 80 microliters of SLS solution (2%, 5%, 7.5%) using filter paper discs. From Tuesday to Friday, we applied 80 microliters of each solution, using filter paper discs, and measured TEWL before and after open application of test solutions. Compared with each corresponding group, TEWL values of SLS patch groups (S-2.0, S-5.0, S-7.5) were higher than those of water patch groups (W-2.0, W-5.0, W-7.5), respectively. TEWL values of each groups increased stepwise and the final (hour 97) TEWL values were higher than those of baseline (hour 0) TEWL. The mean visual scores of the vehicle control were lower than those of other test groups, but there were no statistically significant differences in visual scores between each test group. These findings suggested that impaired skin barrier function, elicited by subclinical irritation from short-duration contact with some irritants, might augment the cumulative irritant contact dermatitis caused by repeated open exposure to other surfactants.(ABSTRACT TRUNCATED AT 250 WORDS)