Irritant effect of a model surfactant on the human vulva and forearm. Age-related differences.

The reactivity of forearm and vulvar skin to sodium lauryl sulfate (SLS) was studied in two groups of 20 healthy women each, 10 before and 10 after menopause. Vulvar skin was less reactive to SLS in both low and high concentrations than was forearm skin. Transepidermal water loss measurement did not seem to be an indicator of irritant dermatitis in vulvar skin. Capacitance measurements, reflecting changes in skin hydration, seemed to be more suitable for monitoring vulvar irritant dermatitis. Age-related differences in irritant reaction were more apparent in low-grade irritant dermatitis induced by low concentrations of SLS than in intense reactions to higher SLS concentrations.