What common childhood disease is caused by the varicella-zoster virus?

The common childhood disease caused by the varicella-zoster virus is chickenpox. It is also called varicella and produces an itchy rash of fluid-filled blisters.

Varicella-zoster virus belongs to the herpesvirus family. Chickenpox usually begins 10–21 days after exposure, often with fever, tiredness, headache, and loss of appetite before the rash becomes obvious. People can spread the virus one or two days before the rash appears, remaining contagious until the lesions crust over.

A common mix-up is confusing chickenpox with shingles. They are caused by the same virus, but shingles is a later reactivation of virus that remains dormant in nerve tissue after an earlier chickenpox infection. Chickenpox is generally more severe in adults and people with weakened immune systems.

The first chickenpox vaccine was introduced in 1974, and routine vaccination has sharply reduced cases in countries that use it widely. The name “chickenpox” has several proposed origins, including the rash’s resemblance to chickpeas or chicken pecks.