26th April 2024

A 70-year-old man presents with a painful rash on the right side of his forehead and scalp, which he first noticed three days ago.

A 70-year-old man presents with a painful rash on the right side of his forehead and scalp, which he first noticed three days ago. He reports that the pain began as a tingling sensation a few days before the rash appeared. On examination, there are grouped vesicles on the side of this face. His visual acuity is normal, but he reports some sensitivity to light.

Which of the following is the most likely diagnosis?