Pathology · single question
A patient presents with left-sided extraoral ulcers AND left intraoral ulcers following the same dermatomal distribution. What is the MOST likely cause?
Show answer and explanation
Correct answer: C. Herpes zoster (shingles)
- A. Incorrect. Erythema multiforme causes bilateral oral ulcers and target skin lesions — not unilateral dermatomal.
- B. Incorrect. Aphthous ulcers are oral only and do NOT follow dermatomal patterns or involve the skin.
- C. Correct. Herpes zoster (VZV reactivation) characteristically presents with ulcers in a UNILATERAL DERMATOMAL distribution, affecting both skin and oral mucosa on the SAME SIDE. This dermatomal unilateral pattern is the hallmark of zoster.
- D. Incorrect. HSV-1 causes perioral lesions but does NOT follow a strict unilateral dermatomal distribution.