Febrile ulceronecrotic Mucha-Habermann's disease is an unusual severe form of pityriasis lichenoides et varioliformis acuta characterized by abrupt onset of ulceronecrotic eruption associated with a high fever and systemic symptoms. To our knowledge, 19 cases of this disease have been reported in the literature, and 4 of them were fatal. We report the case of a 12-year-old boy with this disorder who had abdominal pain, hypoproteinemia, and anemia. Although these associated symptoms are considered life-threatening factors according to reported cases, our patient was successfully treated with methylprednisolone semipulse and subsequent methotrexate therapies. From a review of the literature and the present case, we propose that when patients have these systemic symptoms, therapeutic choices include methotrexate, high-dose corticosteroids, and 4,4-diamino-diphenyl-sulfone, which may depress early development of this disease.