Anisocoria from scopolamine patches.

To the Editor.—Report of a Case.— I was confronted with an unexpected situation while on an expedition in the Galapagos Islands off Ecuador. A 25-year-old woman was noted to have an enlarged left pupil. She complained of drowsiness and diarrhea of one day's duration. My examination revealed a lethargic woman with an 8-mm left pupil fixed to light and convergence. Her remaining neurological examination results were normal. The patient adamantly denied the use of ophthalmic solutions or ointments in the left eye. Her medical history was unremarkable. The grave differential diagnosis of intracranial neoplasm, subdural hematoma, and aneurysm came to mind. After discussing the urgent situation with our ship's captain, I reexamined her and found a scopolamine patch behind her left ear. Her physician in the United States had prescribed it in advance of the trip, and she had prophylactically applied it the previous day before we boarded the yacht.