Chickenpox (varicella)

Chickenpox, also known as varicella, is a respiratory infection caused by a virus. It is spread very easily, is most common in children and is usually mild. It can be very severe or even life threatening to newborn babies, adults and anyone who has a weak immune system. Pregnant women with chickenpox are at increased risk of complications during pregnancy.

After a chickenpox infection the virus stays in the nerve cells of the body in an inactive state. Years later the virus can reactivate causing shingles infection to develop.

Chickenpox is a reportable disease in Ontario.

Chickenpox begins with a fever. Within a day or two, a very itchy rash appears (red spots). The spots turn into fluid-filled blisters, which can cover almost the entire body. They are most likely to appear on the face, ears and scalp, under the arms, on the chest and belly and on the arms and legs. After four or five days, the blisters form crusts and turn into scabs.

Scratching the blisters or scabs can cause bacteria to get into the wounds, leading to other skin infections.

You can treat mild symptoms at home.

You should see a health care provider if the illness seems to be causing more serious symptoms.

The chickenpox virus enters the body by the nose or mouth. The virus spreads easily through the air when a person with chickenpox sneezes or coughs. It can also spread by touching a blister or the liquid from a blister.

A person with chickenpox is able to spread the infection from one or two days before the blisters develop until all the blisters have turned to scabs. It can take two or three weeks to become sick after being in contact with someone who has chickenpox.

A pregnant woman with chickenpox can pass the virus to her baby before and after birth.

Generally there are no medical treatments for a chickenpox infection. Sometimes, however, adults can get a prescription for an antiviral medication and if it is taken within 24 hours of the rash developing it may help shorten the length of the infection or ease the symptoms.

A vaccine is available that protects against chickenpox. It’s available to most people older than 12 months of age.

If you have never had chickenpox, consider getting the vaccine. If you are vaccinated within 72 hours of being in contact with someone who has chickenpox, you might not get sick, and if you do, the illness will be less severe. If you already had chickenpox, you will not get it a second time: you are immune.

If getting the vaccine is not an option, for example if you are pregnant, see your health care provider who may prescribe medications and treatments that can help prevent you from getting chickenpox if they are used soon after you have contact with someone with chickenpox.

Simple preventative measures can reduce the spread of infection.