Reactive arthritis
Arthritis that appears a few weeks after a stomach or urinary infection. Usually temporary, very treatable, and worth recognising early.
What is reactive arthritis?
Reactive arthritis is joint inflammation that develops 1 to 4 weeks after an infection elsewhere in the body — most often a bout of diarrhoea (from bacteria such as Salmonella, Shigella or Campylobacter) or a urinary or genital infection (especially Chlamydia). The joints are not infected themselves; the immune system "reacts" to the earlier infection and inflames them.
It belongs to the spondyloarthritis family, alongside ankylosing spondylitis and psoriatic arthritis, and is more common in people who carry the HLA-B27 gene.
Symptoms to recognise
- Pain and swelling in a few joints, usually in the legs — knees, ankles, toes — often on one side
- Heel pain or pain at the back of the heel (enthesitis)
- A swollen, "sausage-like" toe or finger (dactylitis)
- Red, painful or gritty eyes (conjunctivitis or uveitis)
- Burning on passing urine
- Low back or buttock pain
- Mouth ulcers or rash on the palms and soles in some
How it is diagnosed
- A careful history of recent diarrhoea, urinary symptoms or sexual exposure
- Examination of joints, heels, eyes and skin
- ESR and CRP; HLA-B27 (supportive, not required)
- Urine or swab tests for Chlamydia where relevant; stool tests if diarrhoea is ongoing
- Joint fluid analysis when a single joint is swollen, to rule out infection inside the joint or gout
How it is treated
- NSAIDs (anti-inflammatory painkillers) are the first step for most people
- Steroid injection into a single persistently swollen joint, once infection is ruled out
- If arthritis lasts beyond a few months: sulfasalazine or methotrexate
- Antibiotics treat an active Chlamydia infection (and partners should be treated too), but they do not cure the arthritis that follows a gut infection
- Eye inflammation is treated alongside an ophthalmologist
Most people recover within 3 to 12 months. A minority have recurrent episodes or go on to long-term spondyloarthritis, which is why follow-up matters.
Common questions
Is reactive arthritis contagious?+
How long does reactive arthritis last?+
Will antibiotics cure reactive arthritis?+
Joints flared after an infection?
Reactive arthritis responds well to treatment, and a proper assessment rules out other causes. Walk-in, no appointment needed.
Clinic timings & location