ICD-11 classes
01 Certain infectious or parasitic diseases
Viral infections of the central nervous system
1C80 — Viral encephalitis not elsewhere classified
1F00.21 — Encephalitis due to herpes simplex virus

ICD-11 1F00.21 — Encephalitis due to herpes simplex virus

Herpetic encephalitis is a cerebral infection caused by herpes simplex virus type 1 (HSV1). It presents as acute necrosing temporal encephalitis. Onset is rapid (less than 48 hours) with a fever of 40C, headaches, and behavioural, language and memory problems. These initial manifestations are followed by numbness and coma, which may be accompanied by convulsions and paralysis. This disease, which affects only a small minority of HSV1-infected individuals, results from a primary immune deficiency.

The diagnosis excludes nothing.

It has no clarifying diagnoses.

The diagnosis is coded elsewhere:

• Viral encephalitis not elsewhere classified #636
• Herpes simplex infection of central nervous system #969
• Genetic susceptibility to particular pathogens #3536
• Viral encephalitis not elsewhere classified #8757