Reactive arthritis involves synovitis in one or more joints in response to an infective trigger. Typically it causes acute monoarthritis, affecting a single joint (most often the knee), presenting with a warm, swollen and painful joint.
A significant differential is septic arthritis, where an infection is inside the joint. Patients with reactive arthritis do not have an infection in the joint.
The most common triggers of reactive arthritis are gastroenteritis or sexually transmitted infections. Chlamydia may cause reactive arthritis. Gonorrhoea typically causes septic arthritis rather than reactive arthritis.
Reactive arthritis is a seronegative spondyloarthropathy. There is a link with the HLA B27 gene. It is more common in patients with HIV (HIV needs to be excluded in patients with reactive arthritis).
Associations
- Bilateral conjunctivitis (non-infective)
- Anterior uveitis
- Urethritis (non-gonococcal)
- Circinate balanitis (dermatitis of the head of the penis)
TOM TIP: The classic triad of conjunctivitis, urethritis and arthritis are remembered with the mnemonic, “can’t see, pee or climb a tree”.
Management
Patients presenting with an acute warm, swollen, painful joint need to be treated according to the local hot joint policy. Septic arthritis needs to be excluded. Antibiotics may be given until septic arthritis is excluded.
Joint aspiration is required. Synovial fluid is sent for microscopy, culture and sensitivity testing for infection, and crystal examination for gout and pseudogout.
Management of reactive arthritis (after septic arthritis is excluded) involves:
- Treatment of the triggering infection (e.g., chlamydia)
- NSAIDs
- Steroid injection into the affected joints
- Systemic steroids may be required, particularly where multiple joints are affected
Most cases resolve within 6 months and do not recur. Recurrent cases may require DMARDs or anti-TNF medications.
Last updated August 2023
Now, head over to members.zerotofinals.com and test your knowledge of this content. Testing yourself helps identify what you missed and strengthens your understanding and retention.
