What Is Varicella Zoster?

What is varicella zoster? It is the virus that causes chickenpox, usually in young children. Varicella zoster is a type of herpes virus. After a person recovers from chickenpox, varicella zoster becomes dormant in a person's body--it may reactivate later in life. If you had chickenpox as a young child, you are at risk of developing shingles when you are older.

Chickenpox is a common childhood illness that causes a rash to form on the body. The rash usually consists of red, itchy blisters. Usually, the blisters turn into scabs that fall off the body after a week or so. Some people may experience scarring or pockmarks from the blisters.

If a person is exposed to varicella zoster as a young child, usually the case of chickenpox that develops is not severe and most young children generally recover from it. Catching chickenpox once is enough to build immunity to it. A teenager or adult who hasn't had chickenpox before may be more at risk if he is exposed to varicella zoster, especially if he gets chickenpox. Complications from chickenpox include pneumonia, a bacterial skin infection and brain swelling. Fortunately, a vaccine exists. People who have not had chickenpox, including young children, should get vaccinated.

Varicella zoster often re-emerges in a person many years after he has had chickenpox. It is unclear why the virus re-activates, but when it does, it becomes shingles or herpes zoster. Shingles usually occurs in people over age 60. It appears as a rash, typically only on one side of the body. The rash may be preceded by a sharp pain on one side.

Treatment for shingles usually involves an anti-viral medication prescribed by a doctor. It usually takes about three weeks for the condition to clear up. Both conditions caused by varicella zoster are extremely contagious. A child with chickenpox or a person with shingles should not interact with a person who has not had chickenpox or been vaccinated.