SODIUM LAURYL SULFATE (SLS) INDUCED IRRITANT CONTACT-DERMATITIS - A CORRELATION STUDY BETWEEN CERAMIDES AND IN-VIVO PARAMETERS OF IRRITATION

Sodium lauryl sulfate (SLS), a surfactant frequently used in the induc tion of experimental irritant contact dermatitis in animals and in hum ans, characteristically induces a dose-related increase in TEWL (trans epidermal water loss). Ceramides are considered to be important in the regulation of the skin barrier. We therefore examined,the relationshi p between initial ceramide content of stratum corneum and induced chan ges in skin color (erythema) and barrier function, after SLS applicati on under occlusion (1% and 3% in water) to the forearm of 14 volunteer s. Stratum corneum sheets were removed, stratum corneum lipids extract ed, and ceramide composition determined from chromatograms (TLC) using densitometry. After determining baseline skin color and TEWL at each area, 2 samples of stratum corneum were obtained from each volunteer. Clinical and instrumental controls of the SLS-induced irritation were performed at 24, 48, 72 and 96 h. Erythema was evaluated by colorimetr y; barrier impairment by changes in TEWL. We found inverse correlation s between baseline ceramide 6I (weight) and the 24 h erythema score fo r SLS 3%, between ceramide 1 and 24 h TEWL, and between ceramide 6II a nd 72 h TEWL for SLS 3%. Our findings suggest that low levels of these ceramides may determine a proclivity to SLS-induced irritant contact dermatitis. (C) Munksgaard, 1996.