Reactive Arthritis
Summary
Reactive arthritis is a sterile inflammatory arthritis that develops following an infection, typically gastrointestinal (Campylobacter, Salmonella, Shigella, Yersinia) or genitourinary (Chlamydia trachomatis). It is one of the seronegative spondyloarthropathies and is strongly associated with HLA-B27. The classic triad is arthritis, urethritis, and conjunctivitis (remembered as "Can't see, Can't pee, Can't climb a tree"). Other features include mucocutaneous manifestations such as keratoderma blennorrhagica (pustular rash on soles) and circinate balanitis (painless penile ulcers). Treatment is symptomatic with NSAIDs; Chlamydia should be treated if present, though this does not cure the arthritis. Most cases are self-limiting over 3-12 months.
Key Facts
- Triggers: Chlamydia (GU), Campylobacter/Salmonella/Shigella/Yersinia (GI)
- Triad: Arthritis + Urethritis + Conjunctivitis
- HLA-B27: Positive in 60-80%
- Skin: Keratoderma blennorrhagica, Circinate balanitis
- Treatment: NSAIDs; Treat underlying Chlamydia
- Prognosis: Usually self-limiting (3-12 months)
Clinical Pearls
"Can't See, Can't Pee, Can't Climb a Tree": Memory aid for the triad (Conjunctivitis, Urethritis, Arthritis).
"Sterile Arthritis After Infection": The joint itself is sterile — unlike septic arthritis, no organisms are present in the joint.
"Keratoderma Looks Like Psoriasis": The skin and nail changes in reactive arthritis closely resemble psoriasis.
"Treat Chlamydia, But Arthritis Persists": Treating the underlying STI prevents spread but does not shorten the course of arthritis.
Incidence
- 30-40 per 100,000
Demographics
- M:F = 3:1 (GU-triggered)
- M:F = 1:1 (GI-triggered)
- Peak: Young adults (20-40 years)
Triggering Infections
| Route | Organisms |
|---|---|
| Genitourinary | Chlamydia trachomatis |
| Gastrointestinal | Campylobacter, Salmonella, Shigella, Yersinia |
Mechanism
- Infection triggers immune response
- Cross-reactivity between bacterial antigens and joint tissue
- Sterile inflammation in joints (no viable organisms)
- HLA-B27 increases susceptibility
HLA-B27 Association
- Present in 60-80% of reactive arthritis
- Part of seronegative spondyloarthropathy spectrum
Classic Triad
| Feature | Details |
|---|---|
| Arthritis | Asymmetric oligoarthritis (knees, ankles); Lower limb predominant |
| Urethritis | Dysuria, Discharge |
| Conjunctivitis | Red, gritty eyes; Usually mild |
Other Features
| Feature | Details |
|---|---|
| Uveitis | Anterior uveitis (can be severe) |
| Keratoderma blennorrhagica | Waxy pustules on soles/palms (looks like psoriasis) |
| Circinate balanitis | Painless shallow ulcers on glans penis |
| Nail changes | Onycholysis, Dystrophy |
| Oral ulcers | Painless |
| Enthesitis | Achilles tendonitis, Plantar fasciitis |
| Dactylitis | "Sausage digit" |
Timing
Musculoskeletal
- Asymmetric oligoarthritis (usually lower limb)
- Warm, swollen joints
- Enthesitis (Achilles, Plantar)
- Dactylitis
Skin and Mucosal
- Keratoderma blennorrhagica (soles)
- Circinate balanitis (penis)
- Oral ulcers
Eyes
- Conjunctivitis (bilateral, mild)
- Uveitis (unilateral, severe — refer to ophthalmology)
Blood Tests
| Test | Findings |
|---|---|
| ESR/CRP | Raised |
| HLA-B27 | Positive in 60-80% |
| RF | Negative (seronegative) |
| Anti-CCP | Negative |
Infection Screen
| Test | Purpose |
|---|---|
| Urethral/Cervical swab (NAAT) | Chlamydia |
| Stool culture | GI pathogens (if diarrhoea history) |
Joint Aspiration
- If monoarthritis — Rule out septic arthritis
- Sterile inflammatory fluid (WCC raised, Gram/Culture negative)
Management Approach
┌──────────────────────────────────────────────────────────┐
│ REACTIVE ARTHRITIS MANAGEMENT │
├──────────────────────────────────────────────────────────┤
│ │
│ ACUTE / SYMPTOMATIC: │
│ • NSAIDs (first-line; e.g., Naproxen, Indomethacin) │
│ • Intra-articular corticosteroid injection │
│ • Short course oral steroids (if severe) │
│ │
│ TREAT UNDERLYING INFECTION: │
│ • Chlamydia: Doxycycline or Azithromycin │
│ • GI pathogen: Antibiotics if still active │
│ • ⚠️ Does NOT shorten arthritis duration │
│ • Partner notification and treatment (STI) │
│ │
│ CHRONIC / REFRACTORY (>6 months): │
│ • Sulfasalazine (DMARD) │
│ • Methotrexate (alternative) │
│ • Biologics (Anti-TNF) for severe/refractory │
│ │
│ UVEITIS: │
│ • Urgent ophthalmology referral │
│ • Topical steroids │
│ │
└──────────────────────────────────────────────────────────┘
Musculoskeletal
- Chronic arthritis (10-20%)
- Ankylosing spondylitis (in HLA-B27+)
- Chronic enthesitis
Ocular
- Uveitis (can cause vision loss if untreated)
Skin
- Chronic keratoderma
Acute Episode
- Most cases self-limiting within 3-12 months
Recurrence
- 15-50% have recurrence or chronic course
HLA-B27 Positive
- Higher risk of chronic disease and progression to axial spondyloarthritis
Key Guidelines
- BSR: British Society for Rheumatology Guidelines
What is Reactive Arthritis?
Reactive arthritis is joint pain and swelling that occurs after an infection — usually a gut infection (food poisoning) or a sexually transmitted infection (like chlamydia).
What Are the Symptoms?
- Joint pain and swelling (usually knees or ankles)
- Red, painful eyes
- Burning when urinating
- Sometimes a rash on the soles of your feet
Is It Serious?
For most people, it gets better on its own within a few months. Some people need medication to help with pain and swelling.
How is It Treated?
- Anti-inflammatory tablets (NSAIDs)
- Antibiotics to clear any remaining infection (this won't cure the joint pain but stops spread)
- Steroid injections into the joint if needed
Will It Come Back?
For some people, yes. Regular follow-up with your doctor is recommended.
Primary Resources
- British Society for Rheumatology. Guidelines for the Management of Reactive Arthritis.
Key Studies
- Hannu T. Reactive arthritis. Best Pract Res Clin Rheumatol. 2011;25(3):347-357. PMID: 22100284