The effect on rhino mouse skin of agents which influence keratinization and exfoliation.

The skin of the rhino mouse, an allelic variant of the hariless mouse, contains deep dermal cysts and huge numbers of hornfilled utriculi which resemble comedones. Chemicals which influence either differentiation or desquamation of horny cells were applied topically twice daily for up to 6 weeks. Except for the dermal cysts, the gross epithelial abnormalities were almost completely corrected by retinoic acid in a dose-dependent fashion. Salicylic acid caused partial emptying of the horny masses, but the utriculi did not regress. Lactic acid, propylene glycol and benzoyl peroxide had minor effects on keratinization and exfoliation. The rhino mouse is a suitable model for assessing chemicals which affect epithelial differentiation (retinoids)or which promote loss of cohesion between horny cells (descaling agents).