Dermatophytosis- one of the great imitators. Though, "classically" people think dermatophytosis should appear as a circular lesion, it usually doesn't. It can appear as erythema, scaling, crusting, ulceration, focal kerion, etc. It can really look like anything!
This episodes gives a cliff note version of clinical signs, diagnosis (cytology, DTM, PCR, biopsy, etc.), and treatment.