19th June 2023

A 27-year-old school teacher presented to A&E with a history of confusion, fever and headache for 5 days

A 27-year-old school teacher presented to A&E with a history of confusion, fever and headache for 5 days. She has no significant past medical history and no recent travel history. On assessment, she is febrile with a vesicular rash noted across her trunk. Hepatosplenomegaly is noted on palpation of her abdomen. CT brain appears normal, but CSF analysis shows raised protein with mild lymphocytosis.

Given the clinical features reported, what is the most likely underlying diagnosis?