PassFinals
Musculoskeletal

Reactive arthritis

A sterile inflammatory arthritis that develops after a gastrointestinal or genitourinary infection and commonly follows an asymmetric spondyloarthritis pattern.

In a nutshell

Reactive arthritis is a sterile inflammatory spondyloarthritis that usually begins 1 to 4 weeks after gastrointestinal or genitourinary infection. Exclude septic arthritis, treat any ongoing infection through the correct pathway and manage inflammation symptomatically.

Classic presentation

A young adult with asymmetric lower-limb arthritis, enthesitis or dactylitis a few weeks after gastroenteritis or an STI, with possible eye or genitourinary symptoms.

Key points

  • The joint is usually sterile; the trigger is an infection elsewhere.
  • Typical onset is 1 to 4 weeks after a gastrointestinal or genitourinary infection.
  • A hot joint is septic until investigated: aspirate before steroid injection or immunosuppression.
  • Treat confirmed ongoing STI through sexual-health services with partner notification; antibiotics do not usually shorten the sterile arthritis.
  • Use NSAIDs and other anti-inflammatory treatment after risk assessment, with rheumatology review for persistent disease.
  • Painful red eye with photophobia or blurred vision needs same-day ophthalmology.

First-line investigation

Urgent joint aspiration when monoarthritis is hot, testing for a recent or ongoing trigger infection, inflammatory markers and targeted rheumatology or eye assessment.

Management

Exclude emergencies

  • Aspirate an acutely hot joint and arrange same-day ophthalmology for a painful photophobic red eye.1,2

Find and treat the trigger

  • Use sexual-health testing and partner notification for suspected STI, and treat confirmed ongoing infection using current local guidance.1,3,4

Control inflammation

  • Use risk-assessed NSAID treatment, appropriate corticosteroid options after infection is excluded, and graded movement or physiotherapy.1,2,4

Refer persistent disease

  • Refer prolonged, recurrent or function-limiting arthritis to rheumatology for DMARD or targeted therapy assessment.1,2,4

Safety-net recovery

  • Review function, recurrence, eye symptoms and progression to chronic spondyloarthritis; seek urgent help for fever, a hot joint or visual symptoms.1,2

Exam traps

  • A negative trigger test does not exclude reactive arthritis, because the infection may have resolved.
  • Antibiotics treat an ongoing infection but are not routine treatment for the sterile arthritis itself.
  • Do not inject a hot joint before infection has been excluded.
  • Conjunctivitis-like symptoms with pain or photophobia may be uveitis and need urgent eye review.

Illustrations

Keratoderma blennorrhagicum in reactive arthritisClinical photograph showing hyperkeratotic plaques on the soles, a possible skin manifestation of reactive arthritis.CDC/Dr M. F. Rein, Wikimedia Commons · Public domain

Key sources

  1. NHS: Reactive arthritis (UK clinical and public information on timing, symptoms, urgent red flags, testing, treatment and prognosis.)Updated 16 Dec 2024
  2. NICE NG65: Spondyloarthritis in over 16s: diagnosis and management (UK rheumatology referral, imaging, exercise, symptom control and advanced treatment framework.)Updated 4 Mar 2025
  3. NHS: Chlamydia (UK sexual-health testing, treatment, partner notification and prevention information.)
  4. BNF online (Check current NSAID, corticosteroid, DMARD and antimicrobial prescribing, interactions and monitoring.)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.