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This article waslast modified on 1 February 2019.
What is it?

Reactive arthritis, which is sometimes known as Reiter’s syndrome or disease, can involve a combination of three symptoms:

  • Arthritis – pain, redness and swelling affecting a small number of joints. Most often large joints such as the knee.
  • Uveitis or conjunctivitis – Inflammation of the coating of the eye (conjunctiva) or the front chamber of the eye. Conjunctivitis causes redness and itching. Uveitis is more serious and causes pain and blurring as well as redness.
  • Urethritis – Inflammation of the tube which connects the bladder to the outside of the body (urethra). This causes discharge which will be seen at the tip of the penis or in the vagina. It also causes pain on passing urine.

Reactive arthritis is so called because it normally occurs as a reaction a few weeks after an infection. The exact mechanism is unclear but scientists believe that either the body reacts against itself (autoimmune) or fragments of the infection get into the joint to cause inflammation.

The most common infection that triggers reactive arthritis is chlamydia. It can also occur after other sexually transmitted diseases or after gastroenteritis (food poisoning).

Most people with reactive arthritis have a gene which makes them susceptible. This is called HLA-B27.


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About Reactive Arthritis
  • Tests

    Doctors diagnose reactive arthritis based on the patients’ story and on examination. There are a few tests which may be carried out to rule out other diseases:

    • X-ray or other imaging such as MRI – To examine the joint for any damage or inflammation
    • FBC – to look for excess white cells which may suggest infection
    • ESR – may rise with inflammation
    • CRP – may rise with inflammation
    • Rheumatoid Factor– to help rule out other diseases such as rheumatoid arthritis
    • Autoantibodies – may help rule outsystemic lupus erythematosus
    • HLA-B27- may show that the patient is at risk
    • Synovial Fluid analysis– examination of joint fluid can show alternative diseases such as infection or crystals within the joint

    Doctors may also look for the infection which triggered the reaction:


  • Treatments

    Treatment of the initial infection with antibiotics may be necessary particularly with sexually transmitted infections.  Painkillers such as ibuprofen and paracetamol are widely used.

    Inflamed joints can be injected with steroids or occasionally the fluid can be drained.If the disease is severe and lasts over a couple of months doctors may consider using immunosuppressant drugs.

    Often rest is required initially to control the pain and physiotherapy is also used to maintain a full range of movement.