Chickenpox

Chickenpox is a highly contagious viral infection that mainly affects children. Typical symptoms include a very itchy skin rash with red blisters and a mild fever. Because most children are now vaccinated, chickenpox (also referred to as varicella) is much less common than it was in the past.

If someone becomes infected with chickenpox, they are contagious after just 1 or 2 days, which is before they have any visible rash. But taking precautions and paying attention to hygiene can help to avoid infecting others. Although chickenpox is unpleasant, it rarely has any serious consequences in children who are otherwise healthy. But it may become more severe in newborns and adults, as well as people who have a weakened immune system.

 Symptoms of chickenpox

Fever.

Feeling tired.

Headache.

A stomachache that lasts for one or two days.

A skin rash that is very itchy and looks like many small blisters.

Bumps filled with a liquid that looks like milky water.

Scabs after the blisters break.

Skin that looks blotchy.

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.

Before the varicella shot became a regular part of the recommended vaccination schedule for children, chickenpox was most common in kids. And so arguably, the biggest risk factor for getting chickenpox was being a child under the age of 15. Now the risk factors for coming down with chickenpox boil down to the following.

Not being vaccinated: Coming in contact with VZV if you haven't been vaccinated isn't a guarantee you'll get sick, but the risk is high. The CDC says about 90 percent of unvaccinated people who come in contact with the virus will wind up with the illness. Getting the two-dose varicella vaccine is highly effective: According to the CDC, after the first shot, the vaccine is 85 percent effective at preventing varicella infection. After both doses, the vaccine is more than 90 percent effective at preventing varicella.2

Never having had chickenpox: Once you've had chickenpox, your body will develop a lifelong immunity to it, so that even very direct contact with the varicella virus isn't likely to make you sick. But if you've never had chickenpox, you are at a high risk of getting sick if you're around others who have the illness. Again, the virus spreads incredibly easily, especially in close quarters. Unvaccinated kids are at increased risk of chickenpox if it's going around school or a daycare center, as are teachers and other adults who haven't been vaccinated or had the illness, for example.

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.

Serious complications from chickenpox include:

Bacterial infections of the skin and soft tissues in children, including Group A streptococcal infections.

Infection of the lungs (pneumonia)

Infection or swelling of the brain (encephalitis, cerebellar ataxia)

Bleeding problems (hemorrhagic complications)

The best way to prevent chickenpox is to get the chickenpox vaccine. Everyone—including children, adolescents, and adults—should get two doses of chickenpox vaccine if they have never had chickenpox or were never vaccinated. Chickenpox vaccine is very safe and effective at preventing the disease.