Reactive arthritis is triggered by infection in which systems?

• A. Gastrointestinal or Genitourinary
• B. Respiratory
• C. Cardiovascular
• D. Nervous

Answer: (A)

Reactive arthritis is a post-infectious inflammatory arthritis that follows infection in the gastrointestinal or genitourinary tract. The immune response to these infections can continue to drive joint and enthesis inflammation even after the pathogen is cleared, leading to asymmetric oligoarthritis of the lower limbs, enthesitis, and sometimes conjunctivitis or urethritis. Classic triggers include GI pathogens such as Campylobacter, Salmonella, Shigella, and Yersinia, and the GU pathogen Chlamydia trachomatis. Infections of the respiratory, cardiovascular, or nervous systems are not typical triggers for this condition, which is why gastrointestinal or genitourinary infections are the correct association.