Human Herpes Virus-6 (HHV-6)
What is human herpes virus (HHV-6)?
Human herpes virus 6 (HHV-6) is a virus that infects almost everyone, usually in early childhood. HHV-6 causes roseola or sixth disease, a common viral illness in young children. Roseola symptoms include fever and rash. In most cases, children recover without medical treatment.
HHV-6 stays in the body for life. After infection, the virus stays “asleep” and does not cause symptoms or problems. But if a person has a weak immune system, the virus can sometimes become active and cause illness. This is known as reactivation. In rare cases, the virus can infect organs, such as the skin, liver, brain, lungs, heart, kidneys, stomach, or intestines.
Symptoms of HHV-6 infection
People infected with HHV-6 may show no signs or symptoms. It can take up to 15 days after exposure to the virus for symptoms to appear.
Signs and symptoms of HHV-6 infection include:
- High fever that lasts for 3–5 days
- Red or pink colored rash that does not itch, usually after the fever is gone
- Irritability or fussiness
- Swollen eyelids
- Sore throat
- Runny nose
- Diarrhea
- Vomiting
- Not hungry
- Cough
- Swollen lymph nodes
- Pink or red spots inside the throat
Roseola rash
A rash is common in children with roseola. It usually appears as the fever goes away. It is pink-red in color and usually does not cause discomfort. The rash first develops on the chest, belly, and back and then spreads to the rest of the body. It goes away in a few days.
There are several lab tests for HHV-6. An HHV-6 PCR test shows if there is genetic material (DNA) from the virus in the blood.
If symptoms are more severe, your care team may order other tests to monitor organ function. If a patient shows signs of encephalitis (brain inflammation), a health care provider may do a lumbar puncture to test the cerebrospinal fluid for HHV-6. They may also order an MRI scan to look for brain swelling.
Treatment of HHV-6 infection
Most children will get better on their own. Your health care provider may recommend fever reducers or pain medicines to help manage symptoms. Make sure your child drinks plenty of fluids to prevent dehydration from vomiting or diarrhea.
If your care team suspects a more serious infection or encephalitis, they may prescribe antiviral medicines to fight the virus. Medicines used to treat HHV-6 include ganciclovir, valganciclovir, or foscarnet.
Antibiotics are not used to treat HHV-6 because they only work on bacteria and don’t work for viral illnesses.
If your child had a bone marrow transplant, their transplant and infectious disease teams will decide what treatments are needed.
HHV-6 Reactivation and Stem Cell Transplant
Transplant patients are at higher risk for illness due to HHV-6 infection. HHV-6 may reactivate after a bone marrow transplant (stem cell transplant). During a stem cell transplant, patients get treatments that weaken the immune system, such as high doses of chemotherapy and other medicines. These treatments help stop the body from rejecting a transplant. But because the immune system is weaker than normal and cannot fight infections, HHV-6 may reactivate and cause sickness that can affect the brain, heart, lungs, kidneys, stomach, and intestines.
HHV-6 can also cause serious problems for people with other conditions that weaken the immune system. If your child has symptoms, your care team will use lab tests to check for HHV-6 infection. Your health care provider may recommend treatment based on the test results.
The HHV-6 virus is easily spread through direct contact with an infected person or from droplets when an infected person sneezes or coughs. It can also be spread through a person’s saliva (spit), such as from sharing cups, dishes, or utensils. It can spread easily in places like daycares and schools. Most children have been infected with the virus by the time they are 3 years old.
When to call your care team
HHV-6 may cause serious health problems in patients with weak immune systems. These problems include low blood counts, pneumonia (lung infection), and encephalitis (brain inflammation). Emergency warning signs include:
- Sudden, high fever
- Severe headache
- Drowsiness
- Stiff neck
- Bulging soft spot on the top of a baby’s head
- Seizures
- Confusion
- Memory problems
- Vomiting
Contact your health care provider right away if you notice these symptoms.
Questions to ask your care team
- Are there ways to prevent HHV-6 infection or the spread of the virus?
- How long does the roseola rash last?
- How do I treat my child’s symptoms?
- Is my child at risk for HHV-6 reactivation?
- What symptoms should we watch for?
- What is HHV-6 encephalitis?
- Does my child need antiviral medicines?
- When should I take my child to the emergency room?
Key points about HHV-6 infection
- Human herpes virus-6 (HHV-6) is a common virus that infects nearly everyone, usually in early childhood.
- HHV-6 usually goes away without treatment, but some people may need an antiviral medication.
- Patients are at higher risk for problems due to HHV-6 after a stem cell transplant or if they are immunocompromised.
- If HHV-6 becomes active, it can cause both minor symptoms and serious health problems.
- Contact your doctor if your child has any symptoms of more serious problems after an HHV-6 infection.
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Common Infections
Immunocompromised patients are at risk for serious infections. In some cases, these infections can be life-threatening. Here is more information about common infections in immunocompromised patients.
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Measles
Measles is a viral illness that spreads person to person. Symptoms include fever and rash. Learn about measles and how to prevent measles with an MMR vaccine.
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How to Prevent Infection
Children with serious illnesses can be more vulnerable to infections. Learn more about ways you can protect your child.
