Chickenpox

What is chickenpox?

Chickenpox is caused by the varicella-zoster virus. It is a very common childhood infection that can also affect adults. 

What are the symptoms of chickenpox? 

Chickenpox usually begins with a fever, followed in one or two days by a rash. The rash appears on the chest, back or stomach and spreads to other body areas. It usually starts with spots that soon become fluid-filled blisters. New spots appear over the next two to three days. The blisters then scab over within a few days. The rash is very itchy and may be painful. The illness is usually mild but may be accompanied by a high fever and severe rash.

How do you get chickenpox?

The chickenpox virus spreads very easily from person to person through the air, in saliva, or through direct contact with the fluid in a chickenpox blister. Chickenpox develops 10 to 21 days, most often 14 to 16 days, after a person has been exposed.

When is chickenpox contagious?

Chickenpox is most contagious one or two days before the rash appears. A person may continue to be contagious until five days after the rash appears or until the last blister has crusted over. Between 70 to 90% of siblings of a person with chickenpox will also develop chickenpox if they have not had this infection before or have never received the vaccine against chickenpox. 

Is chickenpox dangerous?

Chickenpox can be dangerous for pregnant women who have not had chickenpox before. Chickenpox is also dangerous for people with a weakened immune system, or for people who are taking drugs that suppress the immune system. If you have been exposed to chickenpox and are pregnant and have not had chickenpox or have not received the chickenpox vaccine, please discuss with your health care provider.  Chickenpox can cause damage to the unborn child if a pregnant woman becomes infected during the early part of her pregnancy.  Chickenpox can also be very serious in an infant born to a mother who gets chickenpox shortly before or after delivery.

A child with chickenpox should be seen by a health care provider as soon as possible if they develop:

  • a fever (>38.3°C) which lasts more than three days or recurs
  • redness, swelling and severe pain around a spot or chickenpox blister
  • a severe headache, sensitivity to bright light, or unusual sleepiness and/or confusion
  • constant vomiting
 

Is there treatment for chickenpox?

There is no specific treatment for chickenpox but in certain circumstances, an antiviral medication can be prescribed by a health care provider. Treatment for the symptoms of itchiness and pain include:

  • Applying a damp cool cloth containing baking soda directly to itchy areas.
  • Applying calamine lotion to the rash and/or bathe in colloidal oatmeal.
  • To control fever and discomfort, it is safe to use acetaminophen, such as Tylenolä. Do not use acetylsalicylic acid (ASA), such as Aspirinä, or any products that contains ASA. ASA increases the risk of developing Reye’s syndrome in children with chickenpox and other viral infections. Reye’s syndrome is a serious illness that can damage the liver and brain. 

Speak with your health care provider before using any lotions or medications.

Encourage children with chickenpox to practise good hand washing and keep their fingernails short. This is very important because bacteria on the hands and skin can infect the chickenpox blisters. 

How do I protect myself against chickenpox?

The best way to protect yourself and your family from chickenpox is by receiving the chickenpox vaccine. Varicella vaccine is recommended for healthy children ages 12 months to 12 years of age. It is included in the routine immunization schedule and is given to children at 15 months of age and again at 4 to 6 years of age. If your child did not receive the chickenpox vaccine and they have not had chickenpox before, please discuss with your health care provider. If you are unsure of your immunization status, contact your health care provider.   

What is Shingles?

Shingles (herpes zoster) looks like chickenpox and is caused by the same virus, but the rash is usually found on one part of the body. Shingles occur in people who have already had chickenpox. It is possible to get chickenpox from someone with shingles through direct contact with the fluid in a blister of the person with shingles. It is not possible to get shingles from a person with chickenpox.

For further information call Ottawa Public Health at 613-580-6744, visit OttawaPublicHealth.ca.

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