Diagnosis and treatment of Lyme arthritis.

In the United States, Lyme arthritis is the most common feature of late-stage Borrelia burgdorferi infection, usually beginning months after the initial bite. In some, earlier phases are asymptomatic and arthritis is the presenting manifestation. Patients with Lyme arthritis have intermittent or persistent attacks of joint swelling and pain in 1 or a few large joints. Serologic testing is the mainstay of diagnosis. Synovial fluid polymerase chain reaction for B burgdorferi DNA is often positive before treatment, but is not a reliable marker of spirochetal eradication after therapy. This article reviews the clinical manifestations, diagnosis, and management of Lyme arthritis.