Reactive Arthritis

Previously called “Reiter’s Syndrome”
  • Eponym dropped because Reiter was a prominent Nazi

Uncommon

Onset 1-4 weeks after triggering infection
  • Chlamydia (genital)
  • GI: Salmonella, Shigella, Campylobacter, Yersinia
Duration:  Most resolve by 6-12 months
 
Pattern:  Asymmetric oligoarthritis (50% legs only)
  • Medium / Large joints
  • Maybe spine involvement, esp. sacro-iliac joints
  • Rarely small-joint
Other possible findings:
  • Enthesitis, esp. heel
  • Dactylitis (“sausage digits”)
  • Eye — conjunctivitis, episcleritis, iritis
  • Genital: urethritis, pelvic pain (men & women)
  • Oral ulcers
  • Keratoderma blennorrhagica (hyperkeratotic skin lesions on soles and palms)
  • Erythema nodosum (painful red nodules on shins)

Lab  —  Not helpful (poor specificity & sensitivity)

Diagnosis  —   completely clinical !!!

** Asymmetric oligoarthritis (esp. hip / knee / ankle) PLUS

  • Recent Chlamydia / Diarrhea = very likely
  • Enthesitis / Dactylitis / Sacroiliitis / Eye = likely
  • Keratoderma blennorrhagica = very likely [but very uncommon]
  • No Other Diagnosis = quite possible

See posting Monoarticular / Oligoarticular Arthritis