Chickenpox FAQs

Chickenpox, also known as varicella, is a very contagious rash illness caused by the varicella zoster virus (VZV).  This virus stays dormant in the body can reactivate later in life to cause shingles (herpes zoster).

Chickenpox causes a fever and an itchy rash that starts on the torso and face and then spreads all over the body. The rash has fluid filled blisters that last for 3 to 7 days before they scab. Other symptoms include itchiness and fever. Some people might not feel well one to two days before the rash appears.

Chickenpox is usually mild, but complications can occur. Young infants, people with suppressed immune systems, and people who are pregnant are at risk for severe illness. If your child is a young infant or has an underlying health condition, notify his or her doctor of chickenpox exposures as soon as possible. 

Complications of chickenpox include secondary bacterial skin infections, dehydration, pneumonia, infection spreading to the nervous system (ex: encephalitis), and bleeding complications. If you notice symptoms of complications, contact your child’s doctor as soon as possible.

Chickenpox used to be a very common illness among children. Since the vaccine for chickenpox was introduced in the United States in the 1990’s, the number of cases, hospitalizations, and deaths has decreased. The number of chickenpox outbreaks nationwide has also gone down since then.

People who have never had the vaccine, including infants younger than 12 months old, are most at risk for getting chickenpox. Someone who is vaccinated or who has had chickenpox before probably will not get chickenpox. However, vaccinated people sometimes get mild cases.  People with mild symptoms can still spread chickenpox to others.

Getting vaccinated is the best way to prevent chickenpox. Children should get one chickenpox vaccination when they are 12 months old and another when they are four years old. Healthy people 13 years and older who have never had chickenpox or been vaccinated should get two doses of the chickenpox vaccine four to eight weeks apart. 

Two doses of the chickenpox vaccine are 88%-98% effective at preventing chickenpox. People who have gotten the chickenpox vaccine may occasionally get mild cases of chickenpox. After vaccination, some mild reactions like fever or pain at the injection site may occur. Most of the time, the vaccine prevents chickenpox and causes no side effects.  If your child experiences a severe adverse reaction after receiving the vaccine, call his or her doctor immediately.

Doctors diagnose chickenpox by examining the patient’s skin and asking about other symptoms and possible exposures. There are laboratory tests available to diagnose chickenpox. These include tests that detect the virus from a skin sample and blood tests that look for the body’s immune response to the virus.

Treatment for chickenpox can include medications to reduce symptoms (ex: fever reducing medications or anti-itch lotions). Sometimes, doctors prescribe antiviral medications to people with chickenpox. These medications can reduce the length and severity of illness if given within 24 hours of rash onset. If you think your child has chickenpox, contact his or her doctor for questions about treatment.

Chickenpox spreads by touching someone with the rash or through the air. Chickenpox can also spread by touching clothing or blankets that someone with chickenpox has used.

People can get chickenpox up to three weeks after they are exposed. Call your child’s doctor if he or she gets a rash in the next three weeks.

The chickenpox vaccine may prevent the illness or reduce symptoms if given within five days of exposure. If it has been at least three months since the first vaccination, children can get the second one before they are four years old. If your child has one chickenpox vaccination, consider getting him or her the second one now.

Some people, including young infants, pregnant women, and people with suppressed immune systems, cannot get the chickenpox vaccine. These groups are at risk for severe disease, and their doctors should be notified immediately of their exposure to chickenpox. If they have been exposed to chickenpox, their doctors might prescribe VARIZIG, an immune globulin, to help prevent illness.

Keep your child home if you think he or she has chickenpox. Call ahead before going into the doctor’s office. This is so the doctor’s office staff can keep your child separate from other patients, to avoid spreading the illness.

People with chickenpox are contagious from two days before the rash starts until the entire rash scabs over. If your child has chickenpox, he or she must stay home, and away from anyone who has not had chickenpox or the vaccine before, until the entire rash scabs over. If the rash does not scab, he or she must stay home until no new spots appear within 24 hours. Your child should avoid contact with infants, pregnant women, and anyone with a suppressed immune system.

Steps that may help prevent spreading illnesses are to avoid close contact with others who are ill, avoid sharing personal items with others who are ill, wash hands often with soap and warm water, and cover coughs and sneezes.