Chickenpox (Varicella)

Overview

What Is Chickenpox?

Chickenpox is an infection that causes a fever and an itchy rash with spots all over the body. It’s due to a virus called varicella-zoster. Chickenpox used to be a common childhood illness in the United States, especially in kids under age 12. It's much rarer now, thanks to the chickenpox vaccine, which helps prevent the infection.

Although chickenpox is usually not a big deal, it can sometimes cause serious problems. The infection usually lasts about 1–2 weeks, but there are ways to help your child feel more comfortable in the meantime.

Top Things to Know

Chickenpox is an infection that spreads easily and is caused by the varicella-zoster virus.
It often starts with a fever or headache, followed by an itchy full-body rash.
Treatment helps ease the itching and medicine may help in some cases.
The chickenpox vaccine protects most kids from getting sick or makes symptoms much milder.

Signs & Symptoms

What Are the Signs & Symptoms of Chickenpox?

Early Symptoms

Chickenpox often starts with a headache, poor appetite, sore throat, stomachache, or fever. These symptoms may last for a few days.

Chickenpox Rash

A red, itchy skin rash usually starts on the belly or back and face. Then it spreads to almost everywhere else on the body, including the scalp, mouth, arms, legs, and genitals.

The chickenpox rash has three stages: red bumps, blisters, and scabs. All three appear on the body at the same time. The rash begins as many small red bumps that look like pimples or insect bites. They appear in waves over 2–4 days, then develop into thin-walled blisters filled with fluid. The blister walls break, leaving open sores, which finally crust over to become dry, brown scabs.

The rash may spread wider or be more severe in kids who have weak immune systems or skin disorders like eczema.

When Should I Call the Doctor?

Most chickenpox infections don't need special medical treatment. But sometimes, problems can happen.

Get medical attention right away if your child:

has trouble breathing
has a severe headache
is very drowsy or has trouble waking up
has trouble looking at bright lights
has trouble walking
seems confused
seems very ill
has a stiff neck

Call the doctor if your child:

has a fever that lasts for more than 4 days
has a bad cough
has an area of rash that leaks pus (thick, yellowish fluid) or becomes red, warm, swollen, or sore
is vomiting

Causes & Prevention

What Causes Chickenpox?

Chickenpox is caused by the varicella-zoster virus. This virus also can cause a painful skin rash called shingles (herpes zoster) later in life. After people have had chickenpox, the virus stays dormant, or resting, in the nervous system for life. The virus can reactivate, or "wake up," later as shingles.

Kids who are vaccinated against chickenpox are much less likely to develop shingles when they get older.

Is Chickenpox Contagious?

Chickenpox is very contagious (easy to catch from someone else). People with chickenpox can spread the virus:

through droplets in the air by coughing or sneezing
in their mucus, saliva (spit), or fluid from the blisters

Most kids with a sibling who is infected also will get chickenpox if they haven't already had the infection or the chickenpox vaccine. They’ll likely have symptoms about 2 weeks after the first child does.

Chickenpox is contagious from about 2 days before the rash starts until all the blisters are crusted over.

Because chickenpox spreads so easily, a child who has it should stay home and rest until the rash is gone and all blisters have dried. This usually takes about 1 to 2 weeks. If you're not sure whether your child is ready to return to daycare or school, ask your doctor.

What About Shingles?

Someone with shingles can spread chickenpox (but not shingles) to people who haven't had chickenpox or the chickenpox vaccine.

Who Needs to Be Extra Careful?

Some people are more at risk for problems if they're exposed to chickenpox, including:

pregnant women
newborns
patients with leukemia (cancer of the white blood cells)
kids receiving medicines that weaken the immune system
anyone with immune system problems

Doctors might give them a medicine to make the illness less severe.

Can Chickenpox Be Prevented?

Yes. The chickenpox vaccine protects most people from chickenpox. And if they do get the infection, their symptoms will be much milder.

Doctors recommend that kids get the chickenpox vaccine as a:

first shot when they're 12–15 months old
booster shot (a dose to help “boost” protection) when they're 4–6 years old

People ages 6 years and older who have never had chickenpox and aren't vaccinated should get two doses of the vaccine.

Kids who have had chickenpox don’t need the vaccine — they usually have lifelong protection against the illness.

How Is Chickenpox Diagnosed?

Doctors usually can diagnose chickenpox by looking at the rash.

Call your doctor if you think your child has chickenpox. You can learn how to watch for problems and find out which medicines can help ease itching.

If you take your child to your doctor, let the staff know ahead of time that your child might have chickenpox. It's important not to expose other kids in the office. For some of them, a chickenpox infection could cause serious problems.

Treatment & Home Care

How Is Chickenpox Treated?

A virus causes chickenpox, so antibiotics (medicines for infections caused by bacteria) can't treat it. But doctors will prescribe antibiotics if bacteria infect the sores. This can happen when kids scratch and pick at the blisters.

Doctors also might prescribe an antiviral medicine, which treats infections caused by viruses, for people with chickenpox who are at risk for problems. This depends on:

their age and health
how serious the infection is
the timing of the treatment

Your doctor can tell you if the medicine is right for your child.

How Can I Help My Child Feel Better?

Rest is important while your child recovers from chickenpox. To help soothe the rash, prevent scratching, and care for mouth sores, follow our guide on how to handle chickenpox at home.