Osteomyelitis and septic arthritis caused by Haemophilus influenzae, type f, in a young girl.

A 4-year-old girl with Legg-Calve Perthes' disease and immunoglobin G1 subclass deficiency developed osteomyelitis of the proximal femur and septic arthritis of the hip secondary to Haemophilus influenzae, type f. This microorganism is a rare cause of invasive infections in children, primarily of the central nervous system (CNS) and respiratory track. It has not previously been associated with bone and joint infections.