Can Chickenpox Cause Encephalitis? Understanding the Risks

February 29, 2024

Featured image for “Can Chickenpox Cause Encephalitis? Understanding the Risks”

Chickenpox, also called varicella, is a common childhood illness caused by the varicella-zoster virus (VZV). It leads to an itchy, blister-like rash along with possible fever, fatigue, and headache. Chickenpox usually follows a benign course, with symptoms resolving in 5-10 days.

However, rarely, serious complications like encephalitis can occur. Encephalitis refers to inflammation of the brain tissue often due to an infectious process. Although uncommon, VZV encephalitis carries significant risks of long-term neurological damage or even death if not treated promptly.

That’s why it’s vital to consult a doctor about any neurological symptoms emerging after chickenpox, especially in high-risk groups like adults or immunocompromised patients. With timely diagnosis and therapy, outcomes can be improved.

What is Encephalitis?

Encephalitis involves irritation and swelling of the brain, typically due to a virus directly invading or triggering an abnormal immune response in the central nervous system.

Potential symptoms include high fever, severe headache, confusion, seizures, weakness, vision changes, and loss of coordination or balance. It can rapidly progress to brain damage or death when left untreated.

Besides initial illness, long-term effects may include recurrent seizures, paralysis, problems with speech or cognition, and other neurologic deficits. Prompt, aggressive treatment is key to preventing permanent sequelae.

How Can Chickenpox Cause Encephalitis?

On rare occasions, the VZV that causes chickenpox can directly invade the brain and spinal cord or spark inflammatory damage to the surrounding membranes (meningitis/myelitis).

This occurs in less than 1% of chickenpox cases, usually 1-6 weeks after the initial viral infection. It appears more common in adults and immunocompromised patients. The precise mechanism behind VZV neurotropism isn’t fully understood and likely involves viral genetics and host immune factors.

When present, chickenpox-related encephalitis carries around a 5-10% mortality risk even with treatment. But again, it is an uncommon, though serious complication to be aware of.

Signs and Symptoms

Be vigilant for any of the following neurological red flags after a recent chickenpox infection:

  • High fever
  • Severe headache
  • Altered mental status – confusion, lethargy
  • Seizures
  • Weakness or paralysis
  • Vision changes
  • Difficulty with balance/coordination
  • Sensory loss

Seek emergency care right away if you notice any of the above – prompt diagnosis and treatment are imperative. Call 911 or go to the nearest ER at the first signs of trouble.

Artboard 1 32

Preventing Encephalitis

The best way to avoid chickenpox encephalitis is prevention – vaccination. The CDC recommends two doses of varicella vaccine for children 12-15 months and 4-6 years old. This prevents over 90% of infections and thereby minimizes complication risks.

For unvaccinated children diagnosed with chickenpox, carefully monitor symptoms for 1-2 months afterwards and watch for any neurologic issues. Contact your doctor immediately about any concerning findings.


  • Chickenpox encephalitis is very rare but can occur after varicella infection
  • Seek emergency care for any neurological red flags post-chickenpox
  • Vaccination helps prevent this serious complication – follow CDC schedules
  • Always consult a doctor regarding suspected cases or complications

Artboard 1 copy 25


What are the chances of getting encephalitis from chickenpox?

Less than 1% of chickenpox cases lead to VZV encephalitis, but immunocompromised patients have higher risks.

What are the long-term effects of encephalitis?

Potential lingering impacts include seizures, paralysis, vision/speech/cognitive problems, and other neurologic deficits.

How is encephalitis treated?

Anti-viral medications, steroids to reduce inflammation, and supportive medical care in the hospital.

Can the chickenpox vaccine prevent encephalitis?

Yes, by preventing initial varicella infection, the vaccine helps minimize the risks of developing encephalitis.

What should I do if I suspect someone has encephalitis?

Seek emergency medical care immediately if you notice any neurologic red flags or alteration in consciousness/cognition.


  • Chickenpox encephalitis is rare but can occur weeks after varicella infection
  • Concerning neurologic symptoms warrant prompt emergency evaluation
  • Vaccination helps prevent this complication – follow CDC guidance
  • Always consult a doctor for suspected cases or complications
Rate this post

Related articles


Cold Plasma System

The world's first handheld cold plasma device

Learn More

Made in USA