Abstract: Objective To establish an animal model of onychomycosis and evaluate the efficacy of 5% amorolfine nail lacquer in the model.Methods We applied Trichophyton mentagrophytes to the nails of the hind limbs of rabbits to establish an experimental,in vivo model of onychomycosis. The nails were taken from the rabbits' feet to histopathological examination after infection success. The growth form of the fungi was evaluated histopathologically. Then 5% amorolfine nail lacquer was applied to the nail for 4 weeks and the efficacy was evaluated by the fungal semiquantitative culture method.Result We successed to establish the onychomycosis model of rabbits that underwent steroid treatment. A cloudy white or pallide-flavens appearance like that of human onychomycosis was observed in the infected nails after inoculation one week. On histopathological examination, hyphae of T.mentagrophytes were seen to penetrate the nail plate, reached the nail bed. The total infection rate at 2, 4, and 6 weeks after inoculation was 52.78%,77.78% and 83.33%, respectively. The culture-positive rate at 2 and 4 weeks after topical treatment was 22.22% and 66.67%, respectively.Conclusion We successed to establish an onychomycosis model in using rabbits and evaluated the efficacy of a topical antifungal agent in this model. The efficacy of 5% amorolfine nail lacque in this model was 66.67% after 4 weeks.

Key words: onychomycosis, rabbit, histopathological examination, fungal culture, 5% amorolfine nail lacque