Herpes zoster virus
The main symptom of chickenpox is a red rash made up of spots or blisters.
It usually takes between one and three weeks for symptoms to appear after becoming infected (the incubation period).
Sometimes other symptoms may start a day or two before the rash appears.
These can include:
Not everyone has these symptoms. They tend to be more common and more severe in older children and adults with chickenpox.
The chickenpox rash develops in three main stages.
The rash starts off as small, raised red spots.
The spots often first appear on the face or trunk before spreading to other parts of the body.
There may just be a few spots or there may be hundreds covering most of the body.
Sometimes spots canappear on thepalms of the hands, the soles of the feet, inside the ears or mouth, or around the bottom or genitals.
During the following hours or thenext day, the spots develop a fluid-filled blister on top.
The blisters may be very itchy, but it's important not to scratch them.
Scratching could spread the infection to others and increases the chances of complications such as a more serious skin infection.
Over the next few days, the fluid in the blistersturns cloudy and the blisters begin to dry out and scab over.
New spotsmay keep appearing for a few days after the rash begins, so there may be a mix of spots, blisters and scabs at the same time.
Chickenpox is contagious untilevery blister has scabbed over, which usually occurs by around five or six days after the rash started.
The scabby crusts will fall off by themselves over the next week or two.
Find out all you need know about chickenpox, including what the symptoms are, how to treat it and when to get medical advice.
Find out about the main symptoms and stages of chickenpox.
Find out how to treat chickenpox at home.