Chickenpox

What Is Chickenpox?

Chickenpox is caused by a virus called varicella-zoster. People who get the virus have:

• a fever
• a rash of spots that look like blisters

They also might get a runny nose, cough, and stomachache.
Thanks to the chickenpox vaccine, kids don’t get chickenpox as much as they once did.

What Are the Signs of Chickenpox?

Chickenpox may start out seeming like a cold: You might have a runny or stuffy nose, sneezing, and a cough.
But 1–2 days later, the rash begins, often in bunches of spots on the chest and face. From there it can spread out quickly over the entire body — sometimes the rash is even in a person’s ears and mouth.
You’ve probably heard that chickenpox is itchy. It’s true! The chickenpox blisters are small and sit on an area of red skin that can be anywhere from the size of a pencil eraser to the size of a dime.
At first, the rash looks like pinkish dots that quickly develop a small blister on top (a blister is a bump on your skin that fills up with fluid). After about 24–48 hours, the fluid in the blisters gets cloudy and the blisters begin to crust over.
Chickenpox blisters show up in waves. So after some begin to crust over, a new group of spots might appear. It usually takes 10–14 days for all the blisters to be scabbed over and then a person is no longer contagious.

How Does Chickenpox Spread?

Chickenpox is contagious, meaning that somebody who has it can easily spread it to other people. Someone with chickenpox is most contagious during the first 2–5 days of being sick. That’s usually about 1–2 days before the rash shows up. So they could spread chickenpox without even knowing it!
People with chickenpox can pass it to others by coughing or sneezing, when tiny drops come out of their mouth and nose. These drops are full of the chickenpox virus. It’s easy for other people to breathe in these drops or get them on their hands. Before you know it, the chickenpox virus has infected someone new.

Learn more about chickenpox.