Erythema nodosum induced by kerion celsi of the scalp.

A 5-year-old girl presented with a 2-week history of a sharply demarcated, inflammatory, granulomatous lesion on the right side of her scalp. Shortly afterward, painful, subcutaneous nodules developed on her shins and thighs. Trichophyton mentagrophytes was isolated from the scalp lesion and a diagnosis of erythema nodosum induced by kerion of the scalp was made. The patient was started on oral therapy with 18 mg/kg/day griseofulvin, associated with topical crystal violet. Her erythema nodosum regressed in 10 days, while the kerion healed 6 weeks later, leaving residual scarring alopecia. Erythema nodosum represents a reaction pattern to a wide variety of inflammatory stimuli. The interest of this case lies in the unusual association of kerion erythema nodosum, of which only nine cases have been reported in the international literature.