Subtalar Joint Septic Arthritis in a Patient with Hypogammaglobulinemia

The clinical presentation of a monoarticular, red, hot, and swollen joint has many possible diagnoses, including septic arthritis, which is 1 of the most devastating. The morbidity associated with this pathologic process involves permanent joint damage and the potential for progression to systemic illness and, even, mortality. The common risk factors for joint sepsis include a history of rheumatoid arthritis, previous joint surgery, joint prosthesis, intravenous drug abuse, alcoholism, diabetes, previous intra-articular steroid use, and cutaneous ulceration. The diagnosis is primarily determined from the culture results after arthrocentesis and correlation with direct visualization, imaging, and various serologies, including synovial analysis. In the present report, a case of an insidious presentation of subtalar joint septic arthritis and its association with a unique patient presentation concomitant with primary immunodeficiency and culture-proven Myocplasma hominis infection is discussed. Septic arthritis has a predilection for the lower extremities and typically is isolated to the hip or knee, with less common involvement of the ankle or metatarsophalangeal joints. Owing to the uncommon nature of primary immunodeficiency disorders and the paucity of studies discussing their association with septic arthridites, we aimed to raise awareness of subtalar joint septic arthritis and to provide a brief overview of the pathogenesis as it presented in a 33-year-old male with X-linked hypogammaglobulinemia/agammaglobulinema.