Erythema nodosum induced by kerion celsi of the scalp in a woman.

A 35-year-old woman, with a 3-week history of an enlarging erythematous, scaly plaque of the scalp vertex associated with the onset of some painful, subcutaneous nodules on her pretibial regions. Trichophyton mentagrophytes was isolated from the scalp lesion and the histological examination of one of the nodular lesions of the legs showed a septal panniculitis. The diagnosis of erythema nodosum (EN) induced by kerion celsi was made and the patient started therapy with oral terbinafine 250 mg per day for 4 weeks associated with naproxene per os 1 g per day for 2 weeks. Erythema nodosum is considered a reaction pattern to a wide variety of microbial and non-microbial stimuli: dermatophytic infections are rarely associated with EN.