A case of Ureaplasma urealyticum septic arthritis in a patient with hypogammaglobulinemia.

Patients with hypogammaglobulinemia have an increased susceptibility to certain infections. We describe the case of a patient with common variable hypogammaglobulinemia for whom the diagnosis of destructive monoarticular arthritis caused by Ureaplasma urealyticum was established after two nondiagnostic open biopsies had been performed. Mycoplasmal infection may involve a joint in hypogammaglobulinemic patients without causing macroscopic purulence in the joint. Histological examination of the bone may be helpful in the differentiation of an infectious process from the rheumatoidlike arthritis that occurs in such patients. Culture of involved bone in addition to synovium or synovial fluid may also be helpful in establishing the diagnosis.