A Diagnostic Challenge: Varicella-Zoster Virus Meningoencephalitis in a Young Medical Student.

Varicella-zoster virus (VZV) meningoencephalitis is an incredibly rare complication following human herpesvirus-3 (HHV-3) infection, primarily diagnosed in children and those who are immunocompromised. The gold standard for diagnosing this illness is polymerase chain reaction (PCR) testing of the cerebrospinal fluid (CSF) after obtaining it through a lumbar puncture, and treating the infection promptly with acyclovir and glucocorticoids.  In this case report, we present a 24-year-old male medical student with nonspecific neurological symptoms. The patient's initial presentation included headaches, fatigue, and cognitive difficulties. Over a three-month period, the patient underwent multiple MRI and CT scans with the assumption that the underlying etiology was autoimmune or chronic in nature, and not something that would be caused by a pathogen of any kind. Persistence of his symptoms eventually prompted a lumbar puncture, revealing VZV in the cerebrospinal fluid and confirming the diagnosis of meningoencephalitis.  This case emphasizes how VZV should remain on the list of differential diagnoses no matter how long the symptoms have persisted because the virus's nature is to remain latent and reactivate in situations of extreme stress. Therefore, if suspected, a lumbar puncture should not be delayed in order to diagnose and treat the condition promptly. Finally, because most cases of this kind of meningoencephalitis are treated within a week of onset of symptoms, we present this case to explore the long-term side effects of VZV encephalitis and its disease progression if it goes untreated.