Reactive arthritis

Reactive arthritis occurring after infections with Chlamydia trachomatis or with enterobacteriae is of special interest because the triggering bacteria are known to be present in the joint. More evidence that C trachomatis persists locally has accumulated. In contrast, despite the first reports on the detection of enterobacteriae DNA in the joint, this seems to be a rare event. Both yersiniae and chlamydiae have been found in peripheral blood cells in patients with reactive arthritis, suggesting that these bacteria reach the joint via the blood. Increasing evidence shows that a failure of the immune response to eliminate these bacteria contributes to their persistence. More T-cell antigens derived from these microbes have been described in the meantime. Diagnosis of reactive arthritis is still a problem that might lead to an underestimation of its prevalence. Some progress has been made in studying the serologic response to these bacteria. Evidence now shows that antibiotics have no role in the treatment of patients with enteric reactive arthritis, but this is less clear for Chlamydia-induced arthritis.