Symptoms:

Most children with chickenpox act sick with vague symptoms, such as a fever, headache, tummy ache, or loss of appetite, for a day or two before breaking out in the classic pox rash. These symptoms last 2 to 4 days after breaking out.

The average child develops 250 to 500 small, itchy, fluid-filled blisters over red spots on the skin (“dew drops on a rose petal”). The blisters often appear first on the face, trunk, or scalp and spread from there. Appearance of the small blisters on the scalp, found in 80% of cases, clinches the diagnosis. After a day or two, the blisters become cloudy and then scab. Meanwhile, new crops of blisters spring up in groups. The pox often appear in the mouth, in the vagina, and on the eyelids. Children with skin problems such as eczema may get more than 1,500 pox.

Most pox will not leave scars unless they become contaminated with bacteria from scratching.

Some children who have had the vaccine will still develop a mild case of chickenpox. They usually recover much quicker and only have a few pox (< 30). These often do not follow the classic descriptions of the disease. However, these mild, post-vaccine cases are contagious.

Signs and tests:

Chickenpox is usually diagnosed from the classic rash and the child's medical history. Blood tests, and tests of the pox blisters themselves, can confirm the diagnosis if there is any question.