Chickenpox is a viral infection that causes an itchy rash of spots all over the body and flu-like symptoms. It used to be a common childhood, especially in kids under age 12. It's much rarer now, thanks to the varicella vaccine that kids get when they're 12 to 15 months old, followed by a booster shot at 4 to 6 years of age.
What Are the Signs and Symptoms of Chickenpox?
Chickenpox often starts without the classic rash, with a fever, headache, sore throat, or stomachache. These symptoms may last for a few days, with the fever in the 101°–102°F (38.3°–38.8°C) range. The red, itchy skin rash usually starts on the abdomen or back and face, then spreads to almost everywhere else on the body (including the scalp, mouth, arms, legs, and genitals). The rash begins as many small red bumps that look like pimples or insect bites. They appear in waves over 2 to 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.
All three stages of the chickenpox rash (red bumps, blisters, and scabs) appear on the body at the same time. The rash may spread wider or be more severe in kids who have weak immune systems or skin disorders like eczema.
What Causes Chickenpox?
Chickenpox is caused by the varicella-zoster virus (VZV). This virus also can cause a painful skin rash called shingles (herpes zoster) later in life. After someone has had chickenpox, the virus stays dormant (sleeping) in the nervous system for the rest of his or her life, even though the chickenpox goes away. The virus can reactivate ("wake up") later as shingles.
Shingles symptoms include tingling, itching, or pain in one area of the body, followed by a rash with red bumps and blisters. Luckily, kids and teens who get shingles almost always have mild cases; severe shingles cases usually are in older people. Kids who are vaccinated against chickenpox are much less likely to develop shingles when they get older. If it does happen, the case of shingles is usually milder and less likely to cause complications than in someone who wasn't immunized.
Is Chickenpox Contagious?
Chickenpox is very contagious — most kids with a sibling who's infected also will get it (if they haven't already had the disease or the vaccine), showing symptoms about 2 weeks after the first child does. The chickenpox virus spreads both through the air (by coughing and sneezing) and by direct contact with mucus, saliva (spit), or fluid from the blisters. Chickenpox is contagious from about 2 days before the rash starts until all the blisters are crusted over.
Someone with shingles can spread chickenpox (but not shingles) to people who haven't previously had chickenpox or the vaccine. (Shingles can only develop in people who have already had chickenpox.) A child with chickenpox should stay home and rest until the rash is gone and all blisters have dried, usually about 1 week. If you're unsure about whether your child is ready to return to school, ask your doctor. Pregnant women, newborns, or anyone with a weakened immune system (for instance, from cancer treatments like chemotherapy or steroids) who gets chickenpox should see a doctor right away.
What Problems Can Happen?
Some people are more at risk for complications from chickenpox, including pregnant women, newborns born to mothers who had chickenpox, patients with leukemia, kids receiving drugs that suppress the immune system, and anyone with immune system problems. If they're exposed to chickenpox, they might be given a medicine (zoster immune globulin) to reduce its severity.
Can Chickenpox Be Prevented?
Yes. The chickenpox vaccine is 99% effective at preventing the infection in kids. Doctors recommend that kids get the chickenpox vaccine as:
Injection when they're 12 to 15 months old.
People 13 years of age and older who have never had chickenpox and aren't vaccinated should get two doses of the vaccine at least 28 days apart to be protected. Few people who've been vaccinated actually develop chickenpox, and those who do tend to have very mild cases and recover quickly.
Healthy kids who have had chickenpox do not need the vaccine — they usually have lifelong protection against the illness.
If a pregnant woman has had chickenpox before the pregnancy, the baby will be protected from infection for the first few months of life, since the mother's immunity is passed on to the baby through the placenta and breast milk.
How Is Chickenpox Diagnosed?
Doctors usually can diagnose chickenpox by looking at the telltale rash at either an in-office visit or a telemedicine visit.
Call your doctor if you think your child has chickenpox. The doctor can guide you in watching for complications and in choosing medicine to ease itching.
If you do take your child to the doctor, let the office know in advance 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 severe complications.
How Is Chickenpox Treated?
A virus causes chickenpox, so antibiotics can't treat it. But sometimes antibiotics are needed if bacteria infect the sores. This is common in kids because they scratch and pick at the blisters.
An antiviral medicine might be prescribed for people with chickenpox who are at risk for complications. The decision to use this will depend on a child's age and health, the extent of the infection, and 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?
To help relieve the itchiness, fever, and discomfort of chickenpox:
Use cool wet compresses or give baths in cool or lukewarm water every 3 to 4 hours for the first few days. Oatmeal bath products, available at supermarkets and drugstores, can help to relieve itching. (Baths do not spread the rash.)
Pat (don't rub) the body dry.
Put calamine lotion on itchy areas (but don't use it on the face, especially near the eyes).
Ask your doctor or pharmacist about pain-relieving creams to apply to sores in the genital area.
Ask the doctor about using over-the-counter medicine for itching. If your child has blisters in the mouth:
Serve cold, soft, and bland foods because chickenpox in the mouth can make drinking or eating difficult. Avoid anything acidic or salty, like orange juice or pretzels.
Give your child acetaminophen to help relieve pain. Never give aspirin to kids with chickenpox. Such use has been linked to a rare but serious disease, Reye syndrome, which can lead to liver failure and even death.
The chickenpox rash is very itchy. As much as possible, discourage kids from scratching to prevent broken blisters and infection. Preventing a bacterial infection is very important. Consider putting mittens or socks on your child's hands to prevent scratching during sleep. Also, trim fingernails and keep them clean.
When Should I Call the Doctor?
Most chickenpox infections don't need special medical treatment. But sometimes, problems can happen. Call the doctor if your child:
has a fever that lasts for more than 4 days or rises above 102°F (38.8°C)
has a severe cough or trouble breathing
has an area of rash that leaks pus (thick, yellowish fluid) or becomes red, warm, swollen, or sore
has a severe headache
is unusually drowsy or has trouble waking up
has trouble looking at bright lights
has difficulty walking
seems very ill or is vomiting
has a stiff neck