Skip to content

Herpes Simplex Encephalitis Susceptibility To 4 C3553869

Published: July 22, 2026Updated: August 20, 2026

A genetic susceptibility to brain inflammation from herpes simplex virus. It affects individuals with specific immune gene variants. Early antiviral treatment is essential for better outcomes.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 20, 2026Editorial policy

Key facts at a glance

ICD-10
G40.909
ICD-11
8A00.0
Body system
neurologic
Severity
severe
Chronic
true

Signs and symptoms

Common signs and symptoms that may indicate this condition.

Warning signs - seek immediate care

!

Altered mental status

!

Headache

!

Seizures

Generalized symptoms

(neurologic)

Significant symptoms that substantially affect daily functioning.

Frequency: Common at all stages

Fever

(neurologic)

Diagnosis and tests

How this condition is diagnosed and what test results mean.

Initial screening tests

1

Standard diagnostic workup

Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]

Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]

Medication Comparisons

Compare medications used to treat Herpes Simplex Encephalitis Susceptibility To 4 C3553869. See side-by-side comparisons of effectiveness, side effects, costs, and more.

View Medication Comparisons

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy