Skip to content

Reactive Arthritis (Reiter Syndrome)

BASICS

  • Definition: Seronegative, multisystem inflammatory disorder triggered by infection (GI or GU). Involves joints, eyes, lower GU tract, and skin.
  • Classic triad: Arthritis, conjunctivitis/iritis, and urethritis/cervicitis ("can't see, can't pee, can't bend my knee").
  • Forms: Sexually transmitted (Chlamydia trachomatis, others), and postenteric infection (Shigella, Salmonella, Yersinia, Campylobacter).

EPIDEMIOLOGY

  • Age: 20–40 years
  • Sex: Male > female
  • Incidence: 0.2–1% after bacterial dysentery outbreaks; 1–2% after nongonococcal urethritis
  • Prevalence: 3–5/100,000 per year

ETIOLOGY & PATHOPHYSIOLOGY

  • Triggers: GU or GI infections (often cleared before rheumatic symptoms). Chlamydia most common sexually transmitted, enteric forms follow dysentery.
  • Immunology: Proinflammatory cytokines, TLRs, HLA-B27 (present in 60–80%; associated with more severe/longer-lasting disease).
  • Genetics: HLA-B27 positive in majority.

RISK FACTORS

  • Recent new or high-risk sexual contact
  • Recent food poisoning, bacterial dysentery, travel
  • HLA-B27 positivity

PREVENTION

  • Avoid triggering infections (safe sex, food/water hygiene)

COMMONLY ASSOCIATED CONDITIONS

  • Enteric disease: Shigella, Salmonella, Campylobacter, Yersinia
  • Urogenital infection: Chlamydia (most common), Mycoplasma, Ureaplasma
  • HIV/AIDS

DIAGNOSIS

  • Clinical: Classic triad (may not all be present), negative rheumatoid factor, preceding GI/GU infection.
  • Not all symptoms appear together. Diagnosis is primarily clinical; no formal criteria.

HISTORY

  • Recent diarrhea, dysentery, urethritis, or genital discharge
  • Symptoms start 7–30 days after infection
  • Asymmetric arthritis (knees, ankles, feet), enthesopathy (plantar fasciitis, Achilles tendinitis), spondyloarthropathy
  • Urethritis (males); cervicitis (females, usually asymptomatic)
  • Eye involvement: conjunctivitis (may be bilateral), rarely uveitis/iritis
  • Mucocutaneous lesions (oral/genital ulcers, keratoderma blennorrhagica)
  • Constitutional: fever, malaise, weight loss

PHYSICAL EXAM

  • Asymmetric arthritis of lower extremities
  • Enthesitis, dactylitis, heel pain
  • Mucocutaneous: oral ulcers, balanitis, psoriasiform lesions (keratoderma blennorrhagica)
  • Eye: conjunctivitis, rarely uveitis/iritis
  • GU: urethritis, prostatitis
  • Cardiovascular: rare (pericarditis, conduction defects)
  • Constitutional: may appear ill, febrile, tachycardic

DIFFERENTIAL DIAGNOSIS

  • Seropositive arthritides (e.g., RA)
  • Ankylosing spondylitis
  • Psoriatic arthritis
  • IBD-associated arthritis
  • Bacterial arthritis (including gonococcal)
  • Rheumatic fever

DIAGNOSTIC TESTS & INTERPRETATION

  • Blood: Rheumatoid factor negative, leukocytosis (10–20k), ↑ESR/CRP, mild normocytic anemia, hypergammaglobulinemia
  • Synovial fluid: Leukocytes 1,000–8,000/mm³, negative cultures/crystals
  • Microbiology: PCR/culture for Chlamydia (urine/genital), stool cultures (rarely necessary)
  • HLA-B27: Positive in 60–80% (not required for diagnosis)
  • Imaging: X-ray may show periosteal proliferation, erosions, joint space narrowing, soft tissue swelling, sacroiliitis
  • HIV testing if indicated

TREATMENT

GENERAL MEASURES

  • Symptom-based approach; physical therapy
  • Treat underlying infection if present (Chlamydia, enteric pathogens)

MEDICATION

First Line: - NSAIDs (e.g., indomethacin, naproxen) - Intra-articular/systemic corticosteroids for refractory arthritis - Specific antibiotics for isolated pathogens (doxycycline for Chlamydia, ciprofloxacin for enteric forms) — Note: antibiotics do not alter the course of arthritis - GI upset: antacids - Iritis/keratitis: topical/intraocular steroids

Second Line: - Sulfasalazine (promising but not FDA-approved) - Methotrexate/azathioprine for severe/refractory cases (consult specialist) - Anti-TNF agents (e.g., etanercept, infliximab) in isolated cases

REFERRAL

  • Rheumatology/ophthalmology for severe, chronic, or complicated cases

ONGOING CARE

  • Activity modification during active disease
  • Monitor response to anti-inflammatories and for drug complications
  • Home physical therapy

PROGNOSIS

  • Acute course: 3–5 months (most recover)
  • 25% develop chronic arthritis (>6 months)
  • Heel, eye, or heart involvement: poorer prognosis
  • HLA-B27 positive: higher risk of chronicity, ankylosing spondylitis (30–50%)

COMPLICATIONS

  • Chronic/recurrent arthritis (5–50%)
  • Ankylosing spondylitis (esp. if HLA-B27+)
  • Urethral strictures, cataracts/blindness, aortic root necrosis

CLINICAL PEARLS

  • Diagnosis is clinical—look for triad (joint, eye, GU) and negative rheumatoid factor.
  • All patients with suspected sexually acquired disease: screen for STI (including HIV).
  • Antibiotic treatment is only effective for underlying infection; does not alter arthritis course.
  • Refer for chronic/recurrent disease or complications.

ICD-10 Codes

  • M02.30 Reiter's disease, unspecified site
  • M02.39 Reiter's disease, multiple sites