Hemophilus influenzae septic arthritis and pneumonia in an adult as the first presentation of multiple myeloma.

We describe an apparently healthy woman who presented with monoarthritis of the right knee and a history of respiratory infection. The synovial fluid cultures grew beta lactamase-negative H. influenzae. Chest roentgenogram showed patchy densities throughout the right lung. Investigations for a predisposing factor for this H. influenzae infection revealed underlying multiple myeloma. As H. influenzae pyoarthrosis is extremely rare in adults, we suggest that an underlying systemic cause be sought in all such patients.