Chickenpox (Varicella)

Chickenpox (Varicella) is is a very contagious disease caused by the varicella-zoster virus (VZV). It causes a rash illness with itching, tiredness, and fever. Chickenpox can be prevented by getting vaccinated.

At-Risk Populations

Chickenpox is most common in young children and typically lasts for 5-7 days.

Some groups are at risk for complications:

  • Pregnant women who have not had chickenpox.
  • People with a weakened immune system.
  • Infants less than 1 year old


Symptoms include an itchy skin rash with blister-like lesions, covering the body. The lesions will scab over in approximately 5 days. It may first appear on the face, chest, and back and then spread to other parts of the body. Many infected individuals have a fever, which develops 1-2 days before the rash appears. People may also experience tiredness, loss of appetite, and headache.

Occasionally, a person who has been vaccinated against chickenpox will become infected. A vaccinated person may get a milder illness with a less severe rash (sometimes involving only a few red bumps that look similar to insect bites) and mild or no fever.

How It Spreads

Chickenpox is very contagious and can be spread from one person to another through the air or through contact with chickenpox blisters. The virus can be transmitted through the air when a person with chickenpox coughs or sneezes. A person is exposed when they breathe in the virus. A person infected with chickenpox will start showing symptoms within 10 - 21 days after being exposed (typically 14-16 days after exposure).

A person with chickenpox can spread the disease from 1-2 days before they get the rash until all their chickenpox blisters have crusted or formed scabs.


Varicella vaccine can prevent chickenpox. Currently, two doses of vaccine are recommended for children, adolescents, and adults. The first dose should be given between 12-15 months of age and the second dose should be given between 4-6 years of age.

If you or your child has been exposed to a person with chickenpox and are not immune*, there are some measures you can take to prevent infection, such as vaccination. What treatment you can receive will depend on your health status and when you were exposed, so please contact your healthcare provider for more information.

*Evidence of immunity is defined as any of the following:

  • Received 2 varicella vaccine doses
  • Laboratory evidence of immunity or laboratory confirmation of disease
  • Verification of history of varicella or zoster (shingles) disease by a health care provider

Testing & Diagnosis

Laboratory testing for chickenpox is recommended. A diagnosis of chickenpox can also be made by observing the symptoms and the typical appearance of the rash.


People can do several things at home to help relieve chickenpox symptoms. Because scratching the blisters may cause them to become infected, keep your fingernails trimmed short. Calamine lotion and oatmeal baths may help relieve some of the itching. Use non-aspirin medications, such as acetaminophen, to relieve fever from chickenpox. The use of aspirin in children with chickenpox has been associated with Reye’s syndrome, a severe disease that affects the liver and brain and can cause death.

A healthcare provider may provide antiviral medication for people with chickenpox who are more likely to develop serious disease:

  • Children less than 1 year old
  • Individuals older than 12 years of age
  • Individuals with a weakened immune system
  • Pregnant individuals

Call your healthcare provider immediately if you or your child develop any of the following symptoms:

  • Fever that lasts longer than four days or rises above 102ºF
  • Any areas of the rash or any part of the body become very red, warm, or tender, or begin leaking pus (thick, discolored fluid), since this may indicate a bacterial infection
  • Difficulty waking up or apparent confusion
  • Difficulty walking
  • Stiff neck
  • Frequent vomiting
  • Difficulty breathing
  • Severe cough

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