Histological changes in rabbits after application of medicaments and cosmetic bases

A staged histological study of skin changes induced in rabbits by daily application of five bases used for topical medicaments and cosmetics, namely glycols, petrolatum, Modulan, Acetulan and Amerchol L 101, over periods of 100 days, is reported. Sections obtained every 10 days were examined for changes in the epithelium, in the character of the dermal infiltrate and in the superficial collagen fibers. Glycols showed no particular effects on the skin; petrolatum produced acanthosis and vacuolization in the epidermis, and mononuclear cell infiltration of the dermis but evident collagen changes. Lanolin derivatives produced acanthosis and vacuolization of the epidermis, with lymphomonouclear infiltration of the dermis and with dissociation of collagen; examination around the 30th day showed a tendency to basal layer disorganization by the infiltrate.