Scleromyxedema: a multicenter study of characteristics, comorbidities, course, and therapy in 30 patients.

Scleromyxedema is associated with a monoclonal gammopathy and other comorbidities. Its prognostic and therapeutic features are poorly documented because most reports deal with single cases or small series. We sought to describe the characteristics of patients with scleromyxedema regarding demographics, clinical characteristics, comorbidities, therapeutic interventions, and course. We conducted a retrospective and prospective multicenter study. We identified 30 patients with scleromyxedema (17 men and 13 women). The mean age at diagnosis was 59 years. The mean delay between disease onset and diagnosis was 9 months. Monoclonal gammopathy was detected in 27 patients. Extracutaneous manifestations were present in 19 patients including neurologic (30%), rheumatologic (23.3%), and cardiac (20%) manifestations. Two patients developed hematologic malignancies. The most common therapies included oral steroids and intravenous immunoglobulins. Although corticosteroids were ineffective, intravenous immunoglobulins (alone or in combination with other drugs) induced complete remission in 4 and partial remission in 9 patients with a mean treatment duration of 2 years. In all, 21 patients were followed up for a mean period of 33.5 months, at which time 16 patients were alive, 12 with and 4 without skin disease. Five patients died: 2 with dermatoneuro syndrome and 1 each with myeloid leukemia, Hodgkin lymphoma, and myocardial insufficiency. This is mainly a retrospective study. Our study confirms that scleromyxedema is a chronic and unpredictable disease with severe systemic manifestations leading to a guarded prognosis. There is no specific definitive treatment. Our data support the contention that intravenous immunoglobulin is a relatively effective and safe treatment. The response is not permanent and maintenance infusions are required.