[Principles of therapy in reactive arthritis]

The diagnosis of reactive arthritis relies mainly on the presence of clinical symptoms caused by the initiating infection in the urogenital or enteral tract. An oligoarthritis mainly of the lower limbs occurs 1-6 weeks later. Chlamydia trachomatis and Yersinia enterocolitica are the most frequent triggers of reactive arthritis. Since the infections caused by these microbes are clinically often asymptomatic diagnostic evaluation can be difficult; serology is often nonspecific and cultures are mostly negative. The microscopic detection of bacterial antigens in the joint and the determination of a bacteria specific lymphocyte proliferation in the synovial fluid have changed the pathogenetic concept of reactive arthritis. However, these methods are technically difficult and not suitable for daily routine. There is no indication for short-term antibiotic treatment, as is often prescribed, except in the case of Chlamydia-induced urethritis, which should be treated in any case to prevent the onset or a relapse of reactive arthritis; the sexual partner must also be treated. Long-term therapy with various antibiotic regimens is now being tested in clinical trials. The symptomatic therapy of arthritis comprises physical methods and the use of nonsteroidal anti-inflammatory drugs; intra-articular administration of corticosteroids is of benefit in some cases. If the arthritis takes a chronic course disease modifying drugs such as sulfasalazine are partly successful; in refractory cases arthroscopic synovectomy may become necessary.