Common variable hypogammaglobulinemia presenting as nontypable Haemophilus influenzae septic arthritis in an adult.

Haemophilus influenzae is a rare cause of septic arthritis in adults. We describe a case of septic arthritis with nontypable Haemophilus influenzae presenting as the first invasive infection leading to a diagnosis of common variable hypogammaglobulinemia. Although nontypable strains have been shown to cause serious infections in adults, they are a rare cause of septic arthritis. Underlying immune deficiency should be considered in an adult who presents with invasive infection with Haemophilus influenzae, regardless of serotype.