We report a case of febrile ulceronecrotic Mucha-Habermann disease (FUMHD) in a 12-year-old boy. After 1 week of typical cutaneous appearance of pityriasis lichenoides et varioliformis acuta (PLEVA), he was given a percutaneous injection of measles virus vaccine, and then extensive polymorphous, papular, and ulcerohemorrhagic skin lesions developed along with intermittent high temperature, hepatic dysfunction, and hypoalbuminemia. Thoracic CT scan showed parenchymal nodular infiltration at the tip of vascular structures. Skin biopsy showed a combination of the classic features of PLEVA and an allergic vasculitis. We treated him with prednisolone and methotrexate (MTX) successfully. The evolution in our patient suggests that FUMHD may have been triggered by virus vaccination. We also emphasize that FUMHD in children may be successfully treated with a combination of systemic MTX and high-dose corticosteroids.