22nd February 2024

An 87-year-old patient develops a vesicular rash on the right side of his forehead.

An 87-year-old patient develops a vesicular rash on the right side of his forehead. Three days later, he experiences sudden double vision and drooping of one eyelid. On examination, the right pupil is looking ‘down and out’, and there is a ptosis on the affected eye. Which cranial nerve is most likely involved in this patient’s condition?