Reactive Arthritis.

Reactive arthritis is classified as a spondyloarthropathy. Current concepts of disease suggest an infectious trigger, followed by inflammatory arthritis. Several mechanisms have been proposed to explain the interaction of host susceptibility and microorganism. Diagnosis relies on a compatible clinical syndrome and microbiologic confirmation of the pathogen. Antibiotic therapy seems useful in Chlamydia-triggered arthritis. The role of antibiotics in arthritis triggered by enteric pathogens is less clear. The role of tumor necrosis factor alpha inhibitors in therapy is evolving. Many patients have a course limited to a few months, but others experience extraarticular disease and more prolonged courses.