A 25-year-old man presents with acute asymmetric oligoarthritis of both ankles and the right knee, conjunctivitis, and painless ulceration on the glans penis. He had an episode of bloody diarrhea 3 weeks ago. Which organism is most likely implicated in this reactive arthritis?
- A Mycobacterium tuberculosis
- B Group A Streptococcus
- C Salmonella ✓
- D Staphylococcus aureus
Correct answer: C. Salmonella
Explanation
Reactive arthritis classically presents with the triad of arthritis, urethritis/conjunctivitis, and mucosal lesions following genitourinary or gastrointestinal infection. Salmonella, Shigella, Campylobacter, Yersinia, and Chlamydia are the most common triggering organisms. Group C Strep triggers rheumatic fever, not reactive arthritis.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.