Rheumatological manifestations of Lyme disease and related tick-borne diseases in north America.

PURPOSE OF REVIEW: Lyme disease is the most common vector-borne infection in North America, and the incidence continues to rise as the geographic range of Ixodes ticks expands. While most patients can be cured with early antibiotic therapy, Lyme arthritis persists as a challenging late manifestation, with a subset developing postantibiotic inflammatory disease that mimics autoimmune arthritis. RECENT FINDINGS: Recent studies have advanced our understanding of Lyme arthritis. Even after bacterial eradication, in some patients, residual antigens in the synovial fluid can sustain immune activation. Immunologic studies demonstrate specific HLA-DRB1 alleles associated with postantibiotic Lyme arthritis, suggesting a predisposition to chronic inflammation. These findings demonstrate that Lyme arthritis is a complex immune-mediated disorder that bridges infectious and autoimmune mechanisms. SUMMARY: Antibiotic therapy is effective for most patients with Lyme arthritis, but optimal management for patients with postantibiotic Lyme arthritis is still uncertain. Continued research into the pathogenesis of postantibiotic Lyme arthritis will be key to improving diagnostic accuracy, refining treatment algorithms, and preventing chronic morbidity associated with Lyme arthritis.