Chickenpox, also known as varicella, is a viral infection that causes a rash that can spread over the entire body.
These blisters eventually form a scab and heal, typically within a week or two.
Chickenpox is highly contagious and can spread quickly from an infected person to others who haven’t had the disease or been vaccinated against it.
While it usually affects children, chickenpox can also spread to adults who haven’t previously had the infection or the chickenpox vaccine. Adolescents and adults are at higher risk for complications from chickenpox.
While you can reduce your risk of catching chickenpox by avoiding contact with people known to be infected, the most effective way to prevent the disease is to get vaccinated.
If you suspect that you or your child has chickenpox, it’s a good idea to see a doctor. Your doctor can make a diagnosis and prescribe any necessary treatments.
Signs and Symptoms of Chickenpox
This rash may start on the chest, back, or face before spreading all over the body.
After about a week, chickenpox blisters typically develop a crust and turn into scabs.
Other common symptoms associated with chickenpox include:
- Reduced appetite
These symptoms may start a day or two before the rash develops. If you develop these symptoms and know that you’ve been exposed to chickenpox, it’s a good idea to stay home to avoid infecting others.
Learn More About Signs and Symptoms of Chickenpox
Causes and Risk Factors of Chickenpox
Chickenpox is caused by a virus called the varicella-zoster virus.
- By breathing in air droplets containing the chickenpox virus (from a person with chickenpox who coughs or sneezes)
- Through direct contact with a chickenpox rash
You’re at high risk for chickenpox in these situations only if you’ve never had the disease or if you haven’t been vaccinated for it. Having the disease or getting vaccinated usually gives you immunity for life.
Chickenpox is contagious starting one to two days before a rash develops until all the blisters have crusted or turned into scabs. If the lesions do not turn into scabs, you are considered contagious until no new lesions have developed for 24 hours.
It’s also possible to get chickenpox from someone with shingles (herpes zoster), a viral infection that occurs when the chickenpox virus, which remains dormant (inactive) in the body after the illness has resolved, reactivates later in life, causing a blistering rash that can be extremely painful.
In the rare situation that you’ve been vaccinated for chickenpox but still get the disease, you can pass on your infection to other people — despite the likelihood that your symptoms will be mild.
There have been cases in which someone gets chickenpox more than once, but this is extremely rare.
Infants, adolescents, adults, pregnant women, and people with a weakened immune system due to illness or medications are at highest risk for chickenpox complications.
How Is Chickenpox Diagnosed?
The rash caused by chickenpox is usually enough for a doctor to diagnose it.
Prognosis of Chickenpox
Duration of Chickenpox
Once you’re exposed to the chickenpox virus, it generally takes 10 to 21 days for you to develop a rash or any other symptoms.
It typically takes about a week for all of the blisters to turn into scabs.
While the symptoms of chickenpox mostly clear up within a week or two, the virus itself stays in a person’s body for the rest of their life. For the most part, the virus remains dormant.
Treatment and Medication Options for Chickenpox
Adults and children at risk of complications may be prescribed antiviral drugs to reduce the severity and duration of chickenpox symptoms.
Children and teenagers should never be given aspirin while they have chickenpox. Doing so raises the risk of developing Reye's syndrome, a serious disease that causes swelling of the brain and liver. Also talk to your doctor before taking any nonsteroidal anti-inflammatory drugs such as ibuprofen (Advil, Motrin) while you have chickenpox, or giving them to a child or teenager with chickenpox, as some studies have linked it to skin infections or tissue damage.
If you or your child has a fever due to chickenpox, taking acetaminophen (Tylenol) can help lower it.
For people with an elevated risk of complications from chickenpox, doctors often prescribe an antiviral drug, such as acyclovir (Zovirax, Sitavig).
Other antiviral drugs that may be options for some people include valacyclovir (Valtrex) and famciclovir (Famvir).
In some cases, your doctor may recommend getting the chickenpox vaccine within three to five days after you've been exposed to the virus, to prevent the disease or reduce its severity.
Alternative and Complementary Therapies
- Calamine lotion (dabbed on itchy spots)
- Baking soda or oatmeal baths
A cool bath with added baking soda, aluminum acetate, uncooked oatmeal, or a colloidal oatmeal preparation may help relieve itching from chickenpox.
Learn More About Treatment for Chickenpox: Medication, Alternative and Complementary Therapies, and More
Prevention of Chickenpox
Two doses of the chickenpox vaccine are needed for effective protection. Most people who receive the vaccine will never develop chickenpox, but those who do tend to have very mild symptoms such as red spots without blisters and little to no fever.
If you haven’t had chickenpox or the vaccine, avoid contact with anyone known to have chickenpox. Talk to your doctor if you believe you may have been exposed to someone with chickenpox in this situation.
Learn More About the Chickenpox Vaccine
Complications of Chickenpox
Complications from chickenpox are uncommon in healthy people and range from mild secondary skin infections to life-threatening brain swelling.
- Bacterial infection (usually affects skin and soft tissues in children)
- Pneumonia (lung infection)
- Brain infection or swelling (encephalitis or cerebellar ataxia)
- Bleeding problems
- Sepsis (bloodstream infections)
The people at highest risk of developing serious complications include infants, teenagers, adults, pregnant women, and people with an impaired immune system due to illness or medications, including people with HIV/AIDS or cancer, people who have had transplants, and people on chemotherapy, immunosuppressive medications, or long-term use of steroids. But even healthy children can develop complications of chickenpox.
While some chickenpox complications are avoidable — for example, not scratching chickenpox blisters reduces the likelihood of skin infections — some are harder to prevent.
The best way to avoid chickenpox complications is to see a doctor for diagnosis and treatment advice if you or your child develops symptoms of chickenpox.
- Low birth weight
- Limb abnormalities
In these cases, the newborn won’t actually be born with chickenpox. But if a woman develops chickenpox right before or after giving birth, it can cause a severe, life-threatening infection.
Learn More About the Complications of Chickenpox: How It Affects Your Body in the Short and Long Term
Research and Statistics: How Many People Get Chickenpox?
BIPOC Communities and Chickenpox
There’s little evidence to suggest that the risk of getting chickenpox is different for any racial or ethnic groups, including Black, Indigenous, and People of Color (BIPOC) populations, in the United States.
However, herpes simplex viruses do not cause chickenpox, and varicella-zoster virus does not cause the sores typical of herpes simplex infections.
In everyone who develops chickenpox, once the infection has passed, the chickenpox virus remains dormant in the body. But the virus can reactivate later in life, causing shingles.
Shingles is marked by a painful rash, usually on one side of the body. It can also occur on the face.
The risk for shingles increases with age, so it’s particularly important for older adults to be vaccinated.
Learn More About Chickenpox in Adults
Resources We Love
Need more information on chickenpox? These organizations can help.
The experts at the Mayo Clinic offer an in-depth discussion of chickenpox and its possible complications.
Centers for Disease Control and Prevention
Parents can learn more about the chickenpox vaccine at the CDC website, including why getting the vaccine is a better idea than allowing children to catch the virus naturally.