Abstract: We studied the effect of different sex hormones on epidermal Langerhans cells (LC) and DNCB-induced allergic contact dermatitis (ACD).25 guinea pigs were randomly divided into 5 groups which received respectively subcutanous injection of sesame oil (group 1), estradiol (group 2), progesterone (group 3), testosterone propionate (group 4), and topical application of testosterone propionate (group 5)once daily for 2 weeks.Then,skin biopsies were taken and the number of LC was counted,LC densities in groups 4 and 5 were significantly lower than those of group 1, 2 and 3 (P<0.01).At the time of skin biopsy,all 5 groups of guinea pigs were sensitized with 2% DNCB, and continued to receive sex hormones and sesame oil for 7 days.Two weeks after sensitization, all groups were challenged with 0.1% DNCB.24 hours after challenge skin reactivity and dermal mononuclear cell responses were assessed, both were significantly lower in groups 4 and 5 than those in groups 1,2 and 3 (P<0.01).We conclude that systematic and topical use of testosterone propionate can inhibit DNCB-induced ACD.

Key words: Sex hormones, Langerhans cells, Allergic, Contact dermatitis