Postvaricella encephalitis

This code represents inflammation of the brain that occurs as a complication following a chickenpox (varicella) infection. It is a neurological sequela of the varicella-zoster virus, typically presenting with altered mental status, seizures, or focal neurological deficits.

Assign this code when documentation clearly indicates encephalitis developing after a confirmed or presumed varicella infection. This diagnosis is typically made based on clinical presentation, cerebrospinal fluid analysis, and imaging studies in a patient with a recent history of chickenpox.

• Ensure the documentation explicitly links the encephalitis to a preceding varicella infection.
• Do not confuse with encephalitis from other viral etiologies; this code is specific to postvaricella.
• Code any residual neurological deficits or sequelae separately, if applicable, and sequence appropriately.