Reactive Arthritis

Basic Information

• Classically occurs 1 to 4 weeks after genitourinary Chlamydia infection
  • “Can’t see (conjunctivitis), can’t pee (urethritis), can’t climb a tree (arthritis)”
    • Previously known as Reiter syndrome
  • In children, most commonly occurs 1 to 4 weeks after bacterial gastroenteritis (Yersinia, Salmonella, Shigella, Campylobacter)
  • Symptoms are due to an immunologic response to preceding infection
    • Occurs most frequently in those who are human leukocyte antigen (HLA)-B27 positive and thus is considered to be a subset of the spondyloarthropathies

Clinical Presentation

• History
  • Preceding diarrheal or genitourinary infection
  • Chlamydia infection is typically asymptomatic, so a history of dysuria and urethral or vaginal discharge may not be elicited
  • Low-grade fever can be present at onset of arthritis
• Physical signs
  • Asymmetric oligoarticular arthritis of the lower extremities, usually markedly painful
    • Unlike juvenile idiopathic arthritis (JIA), overlying erythema is common
  • Conjunctivitis in both Chlamydia and gastroenteritis-associated reactive arthritis may be purulent
  • Skin lesions are occasionally seen with Chlamydia-associated reactive arthritis:
    • Keratoderma blenorrhagicum (scaly psoriasis-like eruption on the feet)
    • Circinate balanitis (painless, shallow ulcers on the glans penis)
    • Erythema nodosum

Diagnosis and Evaluation

• If reactive arthritis is suspected, documentation of a preceding infection is helpful but not always possible:
  1. Stool cultures for enteric organisms
  2. Urethral swab for polymerase chain reaction (PCR) to detect Chlamydia
• Synovial fluid is inflammatory (∼20,000 white blood cells [WBCs]), but cultures are negative
  • Chlamydial antigens or nucleic acids may be detectable in synovial fluid
• Urethral and conjunctival cultures are sterile
• Other laboratory studies can support the diagnosis but are not specific:
  • Elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) and mild leukocytosis with neutrophil predominance

Treatment

• ▪Nonsteroidal anti-inflammatory drugs (NSAIDs) are the first line
  • Chlamydia should be treated, but symptoms may not improve with antibiotics alone
• Usually self-limited and resolves within 6 to 12 weeks, but may last up to 6 months
  • Referral to rheumatology is required for persistent symptoms