An eruption of shingles over the cutaneous distribution of the ophthalmic nerve (herpes zoster ophthalmicus) is a common and often painful affliction. Your patient has involvement over the dorsum of the nose extending to the tip. Which of the following cutaneous branches of the ophthalmic nerve is involved?
(A) external nasal nerve
(B) lacrimal nerve
© supraorbital nerve
(D) supratrochlear nerve
(E) zygomaticotemporal nerve
Explanation:
(A) The external nasal nerve is the terminal cutaneous branch of the anterior ethmoidal nerve (from the nasociliary branch of the ophthalmic nerve). It emerges from the inner surface of the nasal bone to be distributed to the skin down the dorsum of the nose. The lacrimal nerve (choice B) is a branch of the ophthalmic nerve that supplies the lacrimal gland and then becomes cutaneous to supply the conjunctiva and skin of the upper eyelid. The supraorbital nerve (choice C) is a cutaneous branch of the frontal nerve (from the ophthalmic nerve) and is distributed to the skin of the forehead, scalp, and upper eyelid. The supratrochlear nerve (choice D) is a cutaneous branch of the frontal nerve (from the ophthalmic nerve), distributed to the skin of the lower medial forehead. The zygomaticotemporal nerve (choice E) is a cutaneous branch of the maxillary nerve.