Chickenpox is a viral infection in which a person develops extremely itchy blisters all over the body. It used to be one of the classic childhood diseases. However, it has become much less common since the introduction of the chickenpox vaccine.
Causes, incidence, and risk factors
Chickenpox is caused by the varicella-zoster virus, a member of the herpesvirus family. The same virus also causes herpes zoster (shingles) in adults.
Chickenpox can be spread very easily to others. You may get chickenpox from touching the fluids from a chickenpox blister, or if someone with the disease coughs or sneezes near you. Even those with mild illness may be contagious.
A person with chickenpox become contagious 1 to 2 days before their blisters appear. They remain contagious until all the blisters have crusted over.
Most cases of chickenpox occur in children younger than 10. The disease is usually mild, although serious complications sometimes occur. Adults and older children usually get sicker than younger children.
Children whose mothers have had chickenpox or have received the chickenpox vaccine are not very likely to catch it before they are 1 year old. If they do catch chickenpox, they often have mild cases. This is because antibodies from their mothers' blood help protect them. Children under 1 year old whose mothers have not had chickenpox or the vaccine can get severe chickenpox.
Severe chickenpox symptoms are more common in children whose immune system does not work well because of an illness or medicines such as chemotherapy and steroids.
Symptoms
Most children with chickenpox have the following symptoms before the rash appears:
Fever
Headache
Stomach ache
The chickenpox rash occurs about 10 to 21 days after coming into contact with someone who had the disease. The average child develops 250 to 500 small, itchy, fluid-filled blisters over red spots on the skin.
The blisters are usually first seen on the face, middle of the body, or scalp
After a day or two, the blisters become cloudy and then scab. Meanwhile, new blisters form in groups. They often appear in the mouth, in the vagina, and on the eyelids.
Children with skin problems such as eczema may get thousands of blisters.
Most pox will not leave scars unless they become infected with bacteria from scratching.
Some children who have had the vaccine will still develop a mild case of chickenpox. They usually recover much more quickly and have only a few pox (less than 30). These cases are often harder to diagnose. However, these children can still spread chieckenpox to others.
Signs and tests
Your health care provider can usually diagnose chicken pox by looking at the rash and asking questions about the person's medical history. Small blisters on the scalp usually confirms the diagnosis.
Laboratory tests can help confirm the diagnosis, if needed.