Rheumatic manifestations of Bartonella infection in 2 children.

We describe 2 patients with very unusual rheumatological presentations presumably caused by Bartonella infection: one had myositis of proximal thigh muscles bilaterally, and the other had arthritis and skin nodules. Both patients had very high levels of antibody to Bartonella that decreased in association with clinical improvement. Bartonella infection should be considered in the differential diagnosis of unusual myositis or arthritis in children.