Trichophyton (T.) species of Arthroderma (A.) benhamiae is a new emerging pathogen of dermatomycoses in children and adolescents. This zoophilic fungus seems to be more common than other zoophilic dermatophytes, e. g. Microsporum canis transmitted from cats to humans, zoophilic strains of T. interdigitale, and T. verrucosum as cause of ringworm of cattle. Trichophyton species of A. benhamiae is transmitted from guinea pigs (Cavia porcellus form. domestica) to human beings and causes highly inflammatory dermatomycoses both of the face and the scalp. When this dermatophyte produces purulent abscess-forming deep cutaneous infections of the scalp known as kerions, they are both a diagnostic and in particular a therapeutic challenge.