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