Pathology · single question
Recurrent aphthous ulcers (RAS) versus recurrent intraoral herpes (HSV): which statement correctly distinguishes them?
Show answer and explanation
Correct answer: C. RAS is NOT preceded by vesicles and appears on non-keratinized mucosa; HSV IS preceded by vesicles and appears on keratinized tissue
Key distinction: RAS (canker sores) — NOT viral, NOT preceded by vesicles, appears on MOVABLE non-keratinized mucosa (buccal, labial, floor, ventral tongue). Recurrent intraoral HSV — preceded by vesicles, appears on FIXED keratinized mucosa (attached gingiva, hard palate). These two features together distinguish them clearly.
- A. ❌ Only HSV is preceded by vesicles; RAS has NO preceding vesicles.
- B. ❌ These tissue location preferences are REVERSED — RAS is on non-keratinized; HSV on keratinized.
- C. ✅ RAS: not viral, no vesicles, non-keratinized mucosa. HSV: preceded by vesicles, keratinized mucosa. Correct distinction.
- D. ❌ RAS is NOT viral — only HSV has a viral (herpes simplex virus) etiology.