A patient presents with unilateral vesicular lesions that do not cross the midline, beginning near the ear and involving the tongue and palate. Which nerve is affected?

Correct answer: A. Facial nerve (CN VII) — Ramsay Hunt syndrome

• A. CORRECT. Ramsay Hunt syndrome results from VZV reactivation in the geniculate ganglion of the facial nerve (CN VII). It presents with: (1) vesicular eruption in the ear canal and periauricular skin, (2) ipsilateral facial nerve palsy (mimicking Bell's palsy), and (3) involvement of the anterior 2/3 of the tongue via the chorda tympani branch of CN VII. The combination of ear vesicles + tongue involvement = CN VII (not trigeminal).
• B. V3 (mandibular) zoster would produce unilateral lesions on the chin, lower lip, mandibular gingiva, and anterior tongue — but lesion origin near the ear points to CN VII.
• C. Vagus nerve (CN X) involvement would produce pharyngeal or laryngeal symptoms — not periauricular vesicles with tongue involvement.
• D. V2 (maxillary) zoster would produce unilateral lesions on the hard palate, maxillary gingiva, and skin of the cheek/upper lip — not primarily near the ear.