A Rare Case of Varicella-Zoster Virus Encephalitis Presenting With Lost Ability to Play the Piano in an Immunocompetent Pediatric Patient.

Varicella-zoster virus (VZV) is a member of the alpha-herpesvirus family, which can occasionally cause severe neurological complications such as encephalitis. In this case report, we discuss a rare finding of VZV encephalitis in which an immunocompetent pediatric patient, vaccinated against varicella, presented with altered mental status and no vesicular rash. A 15-year-old male presented to the Emergency Department with progressively worsening altered mental status over the past three days. The patient's mother stated that he was exhibiting frequent memory lapses as well as the sudden loss of the ability to play the piano. After admission to the pediatric general floor, lumbar puncture was performed and cerebrospinal fluid analysis returned positive for VZV, confirmed by polymerase chain reaction. The patient was then started on intravenous (IV) acyclovir at a dose of 650 mg every 8 hours to treat VZV-induced encephalitis. While the patient continued to have intermittent episodes of confusion and headaches, his overall condition improved, and by day 4, he was able to resume playing the piano and ukulele. The patient was discharged on day 8 with no home medications, and a follow-up with this primary care physician was scheduled. This patient is one of only four recorded cases of VZV encephalitis in immunocompetent children. It is extremely rare to encounter pediatric patients with this diagnosis and, as such, can elude physicians when developing differential diagnoses. If VZV is suspected, a lumbar puncture should be performed promptly, and, if confirmed, IV acyclovir should be started. Furthermore, this case highlights the need for future research with regard to VZV and potential predisposing factors in immunocompetent patients.