Synovial fluid cultures are negative, suggesting that reactive arthritis is caused either by an autoimmune response involving cross-reactivity of bacterial antigens with joint tissues or by bacterial antigens that have somehow become deposited in the joints. Diagnosis
There are few clinical symptoms, but the clinical picture is dominated by arthritis in one or more joints, resulting in pain, swelling, redness, and heat sensation in the affected areas. The urethra, cervix and the throat may be swabbed in an attempt to culture the causative organisms. Cultures may also be carried out on urine and stool samples or on fluid obtained by arthrocentesis. Tests for C-reactive protein and erythrocyte sedimentation rate are non-specific tests that can be done to corroborate the diagnosis of the syndrome. A blood test for the genetic marker HLA-B27 may also be performed. About 75 percent of all the patients with reactive arthritis have this gene. Diagnostic criteria
Although there are no definitive criteria to diagnose the existence of reactive arthritis, the American College of Rheumatology has published sensitivity and specificity guidelines. Treatment
The main goal of treatment is to identify and eradicate the underlying infectious source with the appropriate antibiotics if still present. Otherwise, treatment is symptomatic for each problem. Nonspecific urethritis may be treated with a short course of tetracycline. Analgesics, particularly NSAIDs, are used. Steroids, sulfasalazine and immunosuppressants may be needed for patients with severe reactive symptoms that do not respond to any other treatment. Local corticosteroids are useful in the case of iritis. Prognosis
Reactive arthritis may be self-limiting, frequently recurring, chronic or progressive.
Reactive arthritis, also known as Reiters syndrome, is a form of inflammatory arthritis that develops in response to an infection in another part of the body (cross-reactivity). Coming into contact with bacteria and developing an infection can trigger the disease. By the time the patient presents with symptoms, often the "trigger" infection has been cured or is in remission in chronic cases, thus making determination of the initial cause difficult. The arthritis often is coupled with other characteristic symptoms; this has been called Reiters syndrome, Reiters disease or Reiters arthritis. The term "reactive arthritis" is increasingly used as a substitute for this designation because of Hans Reiters war crimes with the Nazi Party. The manifestations of reactive arthritis include the following triad of symptoms: an inflammatory arthritis of large joints, inflammation of the eyes in the form of conjunctivitis or uveitis, and urethritis in men or cervicitis in women. Arthritis occurring alone following sexual exposure or enteric infection is also known as reactive arthritis. Patients can also present with mucocutaneous lesions, as well as psoriasis-like skin lesions such as circinate balanitis, and keratoderma blennorrhagicum. Enthesitis can involve the Achilles tendon resulting in heel pain. Not all affected persons have all the manifestations. The clinical pattern of reactive arthritis commonly consists of an inflammation of fewer than five joints which often includes the knee or sacroiliac joint.