Severe meningoencephalitis due to late reactivation of Varicella-Zoster virus in an immunocompetent child.

Recurrent reactivation of latent Varicella-Zoster virus may cause various neurological complications including encephalitis, myelitis, stroke episodes, and meningitis. It occurs mainly in elderly or immunocompromised patients and is very rare in children. We report a 14-year girl who presented with meningoencephalitis due to reactivation of Varicella-Zoster virus 10 years after she had chickenpox and 4 years after she had zoster. Characteristic skin lesions of varicella were absent. Varicella-Zoster virus DNA was detected in cerebrospinal fluid and magnetic resonance imaging (MRI) findings were consistent with small vessel cerebral vasculitis. Treatment with acyclovir and high dose methylprednisolone resulted in near-complete neurological recovery. Although rare, Varicella-Zoster virus may reactivate to cause significant central nervous system disease even in immunocompetent children. Diagnosis depends on a high degree of suspicion because the typical rash may not associate the disease. Characteristic lesions on MRI and the presence of Varicella-Zoster virus DNA in cerebrospinal fluid are key findings for the correct diagnosis.