Trichophyton dermatophytosis--a disease easily confused with pemphigus erythematosus.

Trichophytosis is a rare diagnosis in dogs in Ontario, but recently 4 dogs with a scaling and crusting, alopecic, facial dermatitis have been so diagnosed. In all cases, the histopathological findings of severe epidermal and follicular interface dermatitis, accompanied by an acantholytic intraepidermal pustular dermatitis suggested an immune-mediated disease.