A 17-year-old boy presents with a palatal lesion while under stress, otherwise healthy with no other symptoms. What is the diagnosis?

Correct answer: D. Recurrent herpes (intraoral recurrent herpes simplex)

• A. VZV (shingles) follows a dermatomal pattern and would NOT present as a single palatal lesion in a teenager under stress — this description is classic for recurrent HSV-1.
• B. Aphthous ulcers could fit GENERALLY (stress-triggered, minor symptoms), but aphthous ulcers affect the MOVABLE mucosa (floor of mouth, buccal mucosa, soft palate borders) — NOT the hard palate. The hard palate is a key location.
• C. Primary herpes (first HSV-1 infection) occurs most often in young children (1-5 years), is much more severe (high fever, widespread vesicles, severe pain), and is not the presentation of a single palatal lesion in a stressed teenager.
• D. RECURRENT INTRAORAL HERPES SIMPLEX is the diagnosis. In immunocompetent patients, recurrent HSV-1 lesions occur on KERATINIZED, BOUND MUCOSA (hard palate, attached gingiva) — unlike aphthous ulcers which affect non-keratinized mucosa. STRESS is a classic trigger. The lesion starts as a cluster of small vesicles that ulcerate. The teenager's otherwise healthy status with stress as a trigger and hard palate location = recurrent herpes.