Chickenpox is an infectious disease caused by the varicella-zoster virus which results in a blister-like rash, itching, tiredness and fever. The rash appears first on the trunk and face, but can spread over the entire body causing between 250 to 500 itchy blisters. Most cases of chickenpox occur in persons less than 15 years old. Prior to the use of varicella vaccine, the disease had annual cycles, peaking in the spring of each year.

How do you get chickenpox?

Chickenpox is highly infectious and spreads from person to person by direct contact or through the air from an infected person’s coughing or sneezing. A person with chickenpox is contagious 1-2 days before the rash appears and until all blisters have formed scabs. It takes from 10-21 days after contact with an infected person for someone to develop chickenpox.

How long should a child with chickenpox stay home from school?

A child may return to school not less than 5 days form the first appearance of blisters. Blisters must be crusted over and the child must be fever free.

What is the chickenpox illness like?

In children, chickenpox most commonly causes an illness that lasts about 5-10 days. Children usually miss 5 or 6 days of school or childcare due to their chickenpox. About half of all children with chickenpox visit a health care provider due to symptoms of their illness such as high fever, severe itching, an uncomfortable rash, dehydration or headache. In addition, about 1 child in 10 has a complication from chickenpox serious enough to visit a health care provider including infected skin lesions, other infections, dehydration from vomiting or diarrhea, exacerbation of asthma or more serious complications such as pneumonia.

Certain groups of persons are more likely to have more serious illness with complications. These include adults, infants, adolescents and people with weak immune systems from either illnesses or from medications such as long-term steroids.

What are the serious complications from chickenpox?

Serious complications from chickenpox include bacterial infections which can involve many sites of the body including the skin, tissues under the skin, bone, lungs (pneumonia), joints and the blood. Other serious complications are due directly to the virus infection and include viral pneumonia, bleeding problems and infection of the brain (encephalitis). Many people are not aware that, before a vaccine was available, there were approximately 11,000 hospitalizations and 100 deaths from chickenpox in the U.S. every year. One child and one adult died each week.