Varicella (vair-ih-SELL-uh), commonly known as chickenpox, is a highly contagious disease caused by the varicella-zoster virus (VZV). Infection with VZV causes flu-like symptoms and an itchy rash of red spots, which blister and eventually scab over.

More to Know

VZV spreads both through the air (by coughing and sneezing) and by direct contact with mucus, saliva, or fluid from the blisters. Chickenpox often starts with a fever, headache, sore throat, or stomachache. These symptoms may last for a few days. The red, itchy skin rash follows, usually appearing first on the abdomen or back and face, then spreading to almost everywhere else on the body, including the scalp, mouth, arms, legs, and genitals.

Chickenpox used to be a common illness among kids in the United States, but a vaccine introduced in 1995 has greatly reduced the number of cases. The vaccine prevents the disease in the majority of kids who receive it. Kids who were vaccinated but still get chickenpox tend to develop very mild cases and recover quickly.

Treatment for chickenpox is mainly focused on relieving itching, fever, and discomfort, but medications may be used to treat severe cases.

Keep in Mind

Chickenpox is usually mild, but it can lead to serious complications, especially in older children, adults, and pregnant women. For this reason, anyone with the disease should avoid contact with others until all the blisters have crusted over.

Anyone who has had chickenpox is at risk for developing a condition called shingles (herpes zoster) later in life. Fortunately, this is a rare occurrence in kids and teens with healthy immune systems. It's also uncommon for someone who's been vaccinated against chickenpox to develop shingles later in life.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.