Reactive arthritis

Reactive arthritis is a painful form of inflammatory arthritis that develops in reaction to an infection elsewhere in the body.

The most common sites of infection that lead to arthritis are gastrointestinal and genitourinary. Reactive arthritis can cause inflammation and pain in joints, the skin, eyes, genitals and bladder. It can cause persistent lower back pain. Some people who get reactive arthritis carry the HLA-B27 gene.

Symptoms of reactive arthritis

  • ‘Sausage’ fingers or toes
  • Pain, swelling and stiffness in joints
  • Skin rashes
  • Fingernails and toenails that are thickened and abnormal looking
  • Iritis, uveitis, conjunctivitis
  • Enthesitis (inflammation where tendons attach to the bone)
  • Cystitis (inflammation of the bladder or urinary tract)
  • Genital blisters and sores
  • Lower back or pelvic inflammation and pain

Diagnosis of reactive arthritis

A rheumatologist is best placed to diagnose reactive arthritis. A physical examination, individual and family medical history, blood tests, including for HLA-B27, and X-rays can all help in the diagnosis.

The rheumatologist will look for persistent lower back or buttock pain, pain or stiffness that may be worse in the morning but eases with exercise, signs of a preceding infection either through food poisoning (such as salmonella) or sexual activity (chlamydia). Reactive arthritis typically starts within a few weeks of an infection.


Learn about the management of reactive arthritis.