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Herpes Encephalitis



  • Herpes encephalitis is an infection caused by the herpes simplex virus that causes swelling and irritation (inflammation) of the brain.
  • Herpes encephalitis is treated in the hospital. Your child may get IV fluids and medicines to treat infections and prevent seizures.
  • The best way to prevent herpes encephalitis is to prevent infections. Ask your healthcare provider how to take care of your child at home.


What is herpes encephalitis?

Herpes encephalitis is an infection of the brain and central nervous system caused by the herpes simplex virus.

Herpes encephalitis can be mild, or it may damage the brain and cause trouble walking, talking, and remembering. It can be life-threatening.

What is the cause?

Herpes encephalitis is caused by the same virus that causes cold sores (fever blisters) and genital herpes. The herpes simplex virus causes painful blisters on the skin that can last for several days. Your child may have sores around the mouth or in the genital or buttocks area. Once your child is infected, the virus continues to live in the body, even after the first sores are gone.

Most people with cold sores or genital herpes do not develop encephalitis. In rare cases, the virus spreads to the nerves and brain and causes herpes encephalitis. This usually happens only when your child has a medical condition that weakens the immune system such as diabetes or HIV. The immune system is the body’s defense against infection.

The virus can be passed from a pregnant woman to her baby during birth. It can cause serious problems for the baby, sometimes even death. If a newborn is infected and survives the infection, the baby may have damage to the brain or other parts of the nervous system.

What are the symptoms?

At first, your child may feel or act like he or she has the flu. Your child may have a headache, fever, and muscle aches. Over several hours or days, the symptoms may get worse. More severe symptoms may include:

  • Unusual drowsiness
  • Confusion or changes in alertness
  • Changes in behavior or irritability
  • Sensitivity to light
  • Pain or stiffness in the neck
  • Trouble talking or understanding speech
  • Bulging of the soft spot on an infant’s head
  • Lack of appetite or poor feeding in a baby
  • Skin rash in infants
  • Vomiting
  • Seizures
  • Coma

If your child has these symptoms, call 911 for emergency help right away.

How is it diagnosed?

Your healthcare provider will ask about your child’s symptoms and medical history and examine your child. Tests may include:

  • Blood tests
  • CT scan, which uses X-rays and a computer to show detailed pictures of the brain
  • MRI, which uses a strong magnetic field and radio waves to show detailed pictures of the brain
  • EEG (electroencephalogram), which uses small wires pasted or taped to your child’s head to measure and record the electrical activity of your brain
  • Lumbar puncture, also called a spinal tap, which uses a needle to get a sample of fluid from the area around your child’s spinal cord

How is it treated?

Herpes encephalitis is treated in the hospital. Your child may be in the intensive care unit. If your child needs help breathing, your child may need a breathing machine. These life-support treatments are used until your child starts to get better. Your child may need IV fluids and medicines to:

  • Treat the herpes virus infection
  • Prevent or treat seizures
  • Prevent or treat brain swelling
  • Prevent or treat nausea and vomiting

Your child may start a rehabilitation (rehab) program to help with problems caused by the illness. This may include physical therapy, occupational therapy, or speech therapy.

  • Physical therapy can help your child’s muscles get strong again.
  • Occupational therapy may help if your child has problems doing things such as eating and getting dressed.
  • Speech therapy may help if your child has problems with swallowing, speaking, or understanding words.

How can I take care of my child?

Follow the treatment plan your child’s healthcare provider recommends.

Ask your provider:

  • How and when you will get your child’s test results
  • How to take care of your child at home
  • How long it will take your child to recover from this illness
  • If there are activities your child should avoid and when your child can return to normal activities
  • What symptoms or problems you should watch for and what to do if your child has them

Make sure you know when your child should come back for a checkup. Keep all appointments for provider visits or tests.

How can I help prevent herpes encephalitis?

When your child has herpes blisters anywhere on the body:

  • Avoid touching the blisters. The blister fluid contains live virus. If you do touch a blister, wash your hands as soon as possible. Wash your hands well but gently. This helps prevent damage to your skin and openings for the virus to get into another part of the body. Don’t touch the sores and then touch your eyes or nose, where the infection could be spread.
  • Avoid sharing soaps, washcloths, and utensils for eating or drinking. Dispose of or wash personal items, such as tissues and eating utensils, separately.
  • Teenagers and young adults who may be sexually active should be taught about safe sex practices and how to prevent getting sexually transmitted diseases (STDs) such as herpes.
Developed by Change Healthcare.
Pediatric Advisor 2018.1 published by Change Healthcare.
Last modified: 2017-11-10
Last reviewed: 2017-11-08
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2018 Change Healthcare LLC and/or one of its subsidiaries
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