Febrile ulcero-necrotic Mucha-Habermann disease (FUMHD) is a rare subtype of pityriasis lichenoides et varioliformis acuta (only 41 cases described to date), characterized by an acute onset of ulcero-necrotic papules accompanied by high fever and severe constitutional symptoms. We report a case of a 23-year-old man with a steroid-resistant FUMHD treated by intravenous immunoglobulins (IVIG) combined with methotrexate. Only one case of FUMHD treated by IVIG has been reported to date in literature. Also in our case, IVIG proved to be effective in inducing a dramatic improvement of ulceration and in arresting the appearance of new lesions. Moreover, in our experience we decided to perform a maintenance treatment with extracorporeal photochemotherapy (ECP), to the best of our knowledge not previously used in the treatment of pityriasis lichenoides et varioliformis acuta. ECP, which involves extracorporeal exposure of peripheral blood mononuclear cells to photo-activated 8-methoxypsoralen, induces an immunological reaction against auto-reactive T cell clones, without immune-depression and thus could potentially be useful particularly in FUMHD avoiding the risk of an infective reactivation.