[Reactive arthritis].

In most cases, reactive arthritis occurs after urogenital and gastrointestinal infections. Anamnesis, clinical picture, antigen HLA-B27 determination and serologic antibody ascertainment are of essential importance to the diagnosis. The therapeutic value of antibiotics is questionable, owing above all to the fact that in chlamydia-induced arthritis the causative agent was found in the intraarticular biopsy specimen. The prognosis of the disease is favourable although relapses are frequent. Especially Reiter's disease may have a chronic course.