Chickenpox is a common illness caused by a virus called varicella-zoster. It is usually mild in children, while adults can become very ill. Chickenpox can be very dangerous for people with immune system problems like leukemia, or for people who are taking drugs that weaken the immune system (such as chemotherapy or steroids).
Chickenpox begins with a fever and tiredness, followed in a day or two by an itchy, red rash. The rash usually appears as red spots starting on the face and body. The spots then become fluid-filled blisters and gradually dry and form scabs in four to five days. Some people may only have a few spots while others may have 500 or more.
The chickenpox virus is spread very easily, by direct contact with saliva and/or nasal and blister fluid. It may also be spread by coughing or sneezing. A pregnant woman who is sick with chickenpox either before or shortly after birth may pass it to her baby. It takes 10 to 21 days after contact with an infected person for someone to develop chickenpox. Children are most contagious from 1 to 2 days before to shortly after onset of the rash. Contagiousness persists until crusting of all lesions.
Most children will have the illness for 5 to 10 days. About half of all children with chickenpox will visit their healthcare provider due to symptoms such as itching, high fever, dehydration, and headache. Approximately 1 in 10 children suffer complications such as infected skin lesions, dehydration from vomiting and diarrhea, worsening of asthma, or pneumonia. Adults, pregnant women, young infants, adolescents, and those with weakened immune systems (due to illness or drugs such as steroids) are at risk of more serious complications such as bacterial skin, lung, blood and bone infections, viral brain (encephalitis), and lung infections.
Never give aspirin (acetylsalicylic acid - ASA) or any other products containing aspirin to a child with chickenpox. Taking ASA increases the risk of getting Reye's syndrome. This is a severe illness that can damage the liver and the brain. Use acetaminophen (Tylenol®, Tempra®, Panadol®) for fever and pain.
Skin infections can be prevented by taking good care of the skin and not scratching with fingernails. Luke warm baths, including oatmeal soaks, lightweight clothing and Calamine lotion may help reduce itching. Speak with your healthcare provider about oral medications that can relieve itching.
If your child is sick enough that he or she is unable to take part in normal activities or if he or she has a fever (greater than 38 degrees C/100.4 degrees F), your child should not attend school or daycare. For mild illness, exclusion is not necessary.
If your child has been in contact with someone who has immune system problems or is taking medications that lower the immune system, you should notify them.
For more information, contact KFL&A Public Health at 613-549-1232 or 1-800-267-7875, ext. 1287.
Revised: 2010-04-07