Chapter 162: Reactive Arthritis

DEFINITION

Reactive arthritis (ReA) refers to acute nonpurulent arthritis complicating an infection elsewhere in the body. The term has been used primarily to refer to spondyloarthritides following enteric or urogenital infections

PATHOGENESIS

The bacteria identified as being definitive triggers of ReA include enteric organisms Shigella, Salmonella, Yersinia, Campylobacter species; and genitourinary infection with Chlamydia trachomatis; there is also evidence implicating Clostridium difficile, certain toxigenic Escherichia coli, and possibly other agents.

CLINICAL MANIFESTATIONS

Average age 18–40 years. The male:female ratio following enteric infection is 1:1; however, genitourinary-acquired reactive arthritis is predominantly seen in young males. In a majority of cases, history will elicit symptoms of genitourinary or enteric infection 1–4 weeks prior to onset of other features.

 Constitutional: fatigue, malaise, fever, weight loss.

 Arthritis: usually acute, asymmetric, oligoarticular, involving predominantly lower extremities; sacroiliitis may occur.

 Enthesitis: inflammation at insertion of tendons and ligaments into bone; dactylitis or “sausage digit,” plantar fasciitis, and Achilles tendinitis are common.

 Ocular features: conjunctivitis, usually minimal; uveitis, keratitis, and optic neuritis rarely present.

 Urethritis: discharge intermittent and may be asymptomatic.

 Other urogenital manifestations: prostatitis, cervicitis, salpingitis.

 Mucocutaneous lesions: painless lesions on glans penis (circinate balanitis) and oral mucosa in approximately a third of pts; keratoderma blennorrhagica: cutaneous vesicles that become hyperkeratotic, most common on soles and palms.

 Uncommon manifestations: pleuropericarditis, aortic regurgitation, neurologic manifestations, secondary amyloidosis.

 Reactive arthritis is associated with and may be the presenting sign and symptom of HIV.

EVALUATION

• Pursuit of triggering infection by culture, serology, or molecular methods as clinically suggested.

• Rheumatoid factor and ANA negative.

• Mild anemia, leukocytosis, elevated ESR may be seen.

• HLA-B27 association was initially overestimated with recent studies showing a prevalence <50%. May be helpful in atypical cases and may have prognostic significance.

• HIV screening should be performed in all pts.

• Synovial fluid analysis—often very inflammatory; negative for crystals or infection.

• Radiographs—erosions may be seen with new periosteal bone formation, ossification of entheses, sacroiliitis (often unilateral).

DIFFERENTIAL DIAGNOSIS

Includes septic arthritis (gram +/–), gonococcal arthritis, crystalline arthritis, psoriatic arthritis.