Chickenpox

What is varicella (chickenpox)?

Chickenpox is a very contagious disease caused by the varicella-zoster virus (VZV). It causes a blister-like rash, itching, tiredness, and fever. Chickenpox can be serious, especially in babies, adults, and people with weakened immune systems. It spreads easily from infected people to others who have never had chickenpox or received the chickenpox vaccine. Chickenpox spreads in the air through coughing or sneezing. It can also be spread by touching or breathing in the virus particles that come from chickenpox blisters.

The best way to prevent chickenpox is to get the chickenpox vaccine. Before the vaccine, about 4 million people would get chickenpox each year in the United States. Also, about 10,600 people were hospitalized and 100 to 150 died each year as a result of chickenpox.

How do you get chickenpox?

Anyone who hasn’t had chickenpox or received the chickenpox vaccine can get the disease. Chickenpox most commonly causes an illness that lasts about 5-10 days.

The classic symptom of chickenpox is a rash that turns into itchy, fluid-filled blisters that eventually turn into scabs. The rash may first show up on the face, chest, and back then spread to the rest of the body, including inside the mouth, eyelids, or genital area. It usually takes about one week for all the blisters to become scabs.

Other typical symptoms that may begin to appear 1-2 days before rash include:

  • high fever
  • tiredness
  • loss of appetite
  • headache

Children usually miss 5 to 6 days of school or childcare due to their chickenpox.

Can you get chickenpox if you've been vaccinated?

Some people who have been vaccinated against chickenpox can still get the disease. However, the symptoms are usually milder with fewer blisters and mild or no fever. About 25% to 30% of vaccinated people who get chickenpox will develop illness as serious as chickenpox in unvaccinated persons.

What are the serious complications from chickenpox?

Complications from chickenpox can occur, but they are not as common in otherwise healthy people who get the disease.

People who may have more severe symptoms and may be at high risk for complications include

  • Infants
  • Adolescents
  • Adults
  • Pregnant women
  • People with weakened immune systems because of illness or medications; for example,
    • People with HIV/AIDS or cancer
    • Patients who have had transplants, and
    • People on chemotherapy, immunosuppressive medications, or long-term use of steroids.

Serious complications from chickenpox include

  • dehydration
  • pneumonia
  • bleeding problems
  • infection or inflammation of the brain (encephalitis, cerebellar ataxia)
  • bacterial infections of the skin and soft tissues in children including Group A streptococcal infections
  • blood stream infections (sepsis)
  • toxic shock syndrome
  • bone infections
  • joint infections

Some people with serious complications from chickenpox can become so sick that they need to be hospitalized. Chickenpox can also cause death.

Some deaths from chickenpox continue to occur in healthy, unvaccinated children and adults. Many of the healthy adults who died from chickenpox contracted the disease from their unvaccinated children.

Can chickenpox be prevented?

The best way to prevent chickenpox is to get the chickenpox vaccine. Children, adolescents, and adults should have two doses of chickenpox vaccine.

Chickenpox vaccine is very safe and effective at preventing the disease. Most people who get the vaccine will not get chickenpox. If a vaccinated person does get chickenpox, it is usually mild—with fewer blisters and mild or no fever. The chickenpox vaccine prevents almost all cases of severe disease.

For people exposed to chickenpox, call a health care provider if the person

  • has never had chickenpox disease and is not vaccinated with the chickenpox vaccine
  • has a weakened immune system caused by disease or medication; for example,
    • People with HIV/AIDS or cancer
    • Patients who have had transplants, and
    • People on chemotherapy, immunosuppressive medications, or long-term use of steroids
  • is pregnant

Read more articles from the Centers for Disease Control and Prevention.

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