Chronic recurrent multifocal osteomyelitis in a patient with selective immunoglobulin M deficiency.

Chronic recurrent multifocal osteomyelitis is an unusual inflammatory process of unknown origin involving multiple osseous sites, often recurrently. Selective immunoglobulin M (IgM) deficiency is a rare primary immunodeficiency disease, which can be associated with autoimmune diseases such as systemic lupus erythematosus, Hashimoto's disease, or hemolytic anemia. Here we report a case of a chronic recurrent multifocal osteomyelitis coexisting with selective IgM deficiency.