Stages of Lyme Arthritis

Lyme arthritis was described in 1977, after an apparent outbreak of juvenile idiopathic arthritis in Lyme, Connecticut. The evolution of the disease has been meticulously described with presentation dependent on disease duration and previous therapy.

Erythema migrans is typically the first manifestation. Untreated patients often develop early disseminated disease, characterized by migratory polyarthralgia, potentially with cardiac and/or neurologic sequelae. If untreated, most patients develop late Lyme arthritis, characterized as a monoarthritis or oligoarthritis, typically involving the knees. Serologies are strongly positive at this stage; if positive, Lyme PCR from synovial fluid confirms the diagnosis. Doxycycline is recommended for late Lyme arthritis, although amoxicillin or ceftriaxone may be considered.Initial antibiotic therapy for late Lyme arthritis is insufficient for a subset of patients. However, serologies and synovial fluid PCR are not useful at determining whether infection persists after oral therapy. As such, ceftriaxone is recommended in patients with inadequate response to doxycycline or amoxicillin.Approximately 10% of patients have persistent arthritis despite antimicrobial therapy, termed postinfectious Lyme arthritis, which is thought to be related to prolonged inflammation and unique microbial and host interaction. Therapy at this stage relies on immunosuppression and/or synovectomy.

Lyme arthritis provides unique insights into the complex interplay between microbes and host immunity. The progression from localized erythema migrans to early disseminated disease and late Lyme arthritis allows insight into arthritis initiation, and the study of postinfectious Lyme arthritis allows further insight into mechanisms of arthritis persistence.