Reactive arthritis

Also known as:
Last Review Date: January 13, 2020

What is it?

Reactive arthritis, previously known as Reiter’s syndrome or disease, is so-called because it normally occurs as a reaction to an infection. It appears at between one and four weeks after the infection. It is a combination of three symptoms:

  1. Arthritis – pain, redness and swelling affecting a small number of joints, most often large joints such as the knee.
  2. 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.
  3. Urethritis – inflammation of the tube that connects the bladder to the outside of the body (urethra). This causes a discharge which will be seen at the tip of the penis or in the vagina. It also causes pain on passing urine.

The exact mechanism of reactive arthritis is unclear but it is believed 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.


A diagnosis of reactive arthritis is based on the someone's clinical history and on examination. There are tests that can be used 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 – to help rule out systemic lupus erythematosus
  • HLA-B27 — a genetic test that can show if someone is at risk
  • Synovial fluid analysis – examination of joint fluid can show alternative diseases such as infection or crystals within the joint

It is also possible to look for the infection which triggered the reaction:


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 more than a couple of months, doctors may consider using immunosuppressant drugs.

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

Related pages

Elsewhere on the web
Arthritis Victoria: Reactive arthritis
Australian Rheumatology Association: Patient information Reactive arthritis