Chickenpox

Overview

Chickenpox is an infection caused by the varicella-zoster virus. It causes an itchy rash with small, fluid-filled blisters. Chickenpox is highly contagious to people who haven't had the disease or been vaccinated against it. Today, a vaccine is available that protects children against chickenpox. Routine vaccination is recommended by the U.S. Centers for Disease Control and Prevention (CDC).

The chickenpox vaccine is a safe, effective way to prevent chickenpox and its possible complications.

Symptoms

Symptoms of chickenpox typically appear within 10 to 21 days after you’ve been exposed to the virus. The first sign is usually a general feeling of being unwell. That’s normally followed by these symptoms:

• Body aches
• Fever
• Feeling extremely tired (fatigue)
• Feeling irritable
• Loss of appetite
• Headache

Within a day or 2, you’ll develop the telltale chickenpox rash. It unfolds in three phases.

During the first phase, you’ll develop itchy, raised, pink or red bumps. Doctors call these “papules.” As many as 250 to 500 of them can pop up all over your body. In severe cases, they can even form in your mouth, eyes, anus, or genitals.

Over the next several days, these bumps will turn into small, fluid-filled blisters called “vesicles.” They last about a day before they pop and start to leak.

Finally, these open wounds crust over and turn into scabs. As they heal, new bumps continue to appear. You could have bumps, blisters, and scabs at the same time. You can spread the virus to other people until all the spots crust over.

Most cases of chickenpox are mild and go away on their own. But see your doctor right away if you develop any of the following symptoms:

• The rash spreads to one or both eyes
• The rash gets very red, warm, or tender. You could have a bacterial skin infection.
• Dizziness
• Shortness of breath
• Vomiting
• Stiff neck
• You can’t control your muscles
• Fever over 102 F
• Dehydration

Causes

Chickenpox infection is caused by the varicella-zoster virus. It can spread through direct contact with the rash. It can also spread when a person with the chickenpox coughs or sneezes and you inhale the air droplets.

Risk factors

Your risk of becoming infected with the varicella-zoster virus that causes chickenpox is higher if you haven't already had chickenpox or if you haven't had the chickenpox vaccine. It's especially important for people who work in child care or school settings to be vaccinated.

Most people who have had chickenpox or have been vaccinated against chickenpox are immune to chickenpox. A few people can get chickenpox more than once, but this is rare. If you've been vaccinated and still get chickenpox, symptoms are often milder, with fewer blisters and mild or no fever.

Complications

Chickenpox is normally a mild disease. But it can be serious and can lead to complications including:

• Bacterial infections of the skin, soft tissues, bones, joints or bloodstream (sepsis)
• Dehydration
• Pneumonia
• Inflammation of the brain (encephalitis)
• Toxic shock syndrome
• Reye's syndrome in children and teenagers who take aspirin during chickenpox
• Death

Who's at risk?

• People who are at higher risk of chickenpox complications include:
• Newborns and infants whose mothers never had chickenpox or the vaccine
• Adolescents and adults
• Pregnant women who haven't had chickenpox
• People who smoke
• People whose immune systems are weakened by medication, such as chemotherapy, or by a disease, such as cancer or HIV
• People who are taking steroid medications for another disease or condition, such as asthma

Chickenpox and pregnancy

Low birth weight and limb abnormalities are more common among babies born to women who are infected with chickenpox early in their pregnancy. When a mother is infected with chickenpox in the week before birth or within a couple of days after giving birth, her baby has a higher risk of developing a serious, life-threatening infection.

If you're pregnant and not immune to chickenpox, talk to your doctor about the risks to you and your unborn child.

Chickenpox and shingles

If you've had chickenpox, you're at risk of a complication called shingles. The varicella-zoster virus remains in your nerve cells after the skin infection has healed. Many years later, the virus can reactivate and resurface as shingles — a painful cluster of short-lived blisters. The virus is more likely to reappear in older adults and people who have weakened immune systems.

The pain of shingles can last long after the blisters disappear. This is called postherpetic neuralgia and can be severe.

The shingles vaccine (Shingrix) is recommended for adults who have had chickenpox. Shingrix is approved and recommended for people age 50 and older, including those who've previously received another shingles vaccine (Zostavax). Zostavax, which isn't recommended until age 60, is no longer sold in the United States.

Prevention

The chickenpox (varicella) vaccine is the best way to prevent chickenpox. Experts from the CDC estimate that the vaccine provides complete protection from the virus for nearly 98% of people who receive both of the recommended doses. When the vaccine doesn't provide complete protection, it significantly lessens the severity of chickenpox.

The chickenpox vaccine (Varivax) is recommended for:

Young children. In the United States, children receive two doses of the varicella vaccine — the first between ages 12 and 15 months and the second between ages 4 and 6 years — as part of the routine childhood vaccination schedule.

The vaccine can be combined with the measles, mumps and rubella vaccine, but for some children between the ages of 12 and 23 months, the combination may increase the risk of fever and seizure from the vaccine. Discuss the pros and cons of combining the vaccines with your child's doctor.

Unvaccinated older children. Children ages 7 to 12 years who haven't been vaccinated should receive two catch-up doses of the varicella vaccine, given at least three months apart. Children age 13 or older who haven't been vaccinated should also receive two catch-up doses of the vaccine, given at least four weeks apart.

Unvaccinated adults who've never had chickenpox and are at high risk of exposure. This includes health care workers, teachers, child care employees, international travelers, military personnel, adults who live with young children and all women of childbearing age.

Adults who've never had chickenpox or been vaccinated usually receive two doses of the vaccine, four to eight weeks apart. If you don't remember whether you've had chickenpox or the vaccine, a blood test can determine your immunity.

The chickenpox vaccine isn't approved for:

Pregnant women

People who have weakened immune systems, such as those who are infected with HIV, or people who are taking immune-suppressing medications

People who are allergic to gelatin or the antibiotic neomycin

Talk to your doctor if you're unsure about your need for the vaccine. If you're planning on becoming pregnant, consult with your doctor to make sure you're up to date on your vaccinations before conceiving a child.

Is it safe and effective?

Parents typically wonder whether vaccines are safe. Since the chickenpox vaccine became available, studies have consistently found it to be safe and effective. Side effects are generally mild and include redness, soreness, swelling and, rarely, small bumps at the site of the shot.

Treatment

Chickenpox usually runs its course in 5 to 10 days. But if you have the itchy rash caused by the virus, that can feel like a very long time. Fortunately, there are things you can do at home to ease your symptoms while your body heals itself.

Use Acetaminophen (Tylenol) for Pain and Fever

If you or your child has a high fever or achiness caused by chickenpox, reach for the Tylenol. It can even help relieve pain associated with sores that develop on your skin or in your mouth. It’s safe for most people, including pregnant women and children over 2 months old.

Avoid anti-inflammatory painkillers, like ibuprofen. If you have chickenpox, it can make you very ill. Never give aspirin to children under age 16. It can lead to a serious complication called Reye’s syndrome.

Don’t Scratch That Itch

Yes, it’s tempting. But scratching your rash can put you at risk for a bacterial skin infection. It could also cause scarring. Try these tips to calm your itchy skin:

• Tap or pat -- don’t scratch -- your itch
• Take a cool oatmeal bath (you can buy it at your local drugstore). Dab or pat (don’t rub) your skin dry.
• Wear loose, cotton clothing so your skin can breathe
• Dab calamine lotion on your itchy spots
• Try an antihistamine, like Benadryl, to ease your symptoms
• Keep Your Cool
• Heat and sweat make you itch more. Use a cool, wet washcloth on super-itchy areas to calm your skin.

Stay Hydrated

Drink lots of fluids to help your body rid itself of the virus faster. It’ll also keep you from getting dehydrated.

Choose water over sugary drinks or sodas, especially if you or your child has chickenpox in the mouth. Sugar-free popsicles are a good choice, too.

Avoid hard, spicy, or salty foods that can make your mouth sore.

Prescription Medications

If you’ve been exposed to someone who has chickenpox but doesn’t have symptoms yet, your doctor may give you an injection of a treatment called immunoglobulin. It can help prevent severe chickenpox. Your doctor may consider this therapy if you’re:

• Pregnant
• A smoker
• Living with HIV
• Having chemotherapy (“chemo”) or taking high doses of steroid medication
• Newborn babies under 4 weeks old are also at increased risk for complications from chickenpox.

If you’re at risk for severe chickenpox and already have symptoms, your doctor might prescribe an antiviral medication called acyclovir (Sitavig, Zovirax). It can help to make your symptoms less severe. You’ll take the first dose within 24 hours of developing the rash. Then you’ll take a tablet 5 times a day for 7 days.

Understanding Chickenpox -- Prevention

The American Academy of Pediatrics recommends that children be immunized with the varicella zoster vaccine to prevent chicken pox usually after the age of 1. A second dose, typically given at about age 4 or 5, is needed for complete protection.

The vaccine is also a protection to vulnerable people, such as non-immune women who plan to become pregnant. Some, such as those who are already pregnant, are not eligible to receive the chickenpox vaccine. Consult your doctor for advice.

A similar vaccine -- but in a higher dose -- is also available for the elderly who already had chickenpox to prevent painful outbreaks of shingles. Those over 65 can consult their doctors to see if this higher dose vaccine may help them.