health

Infection with the varicella zoster (var-uh-SEH-luh ZOS-ter) virus*
(VZV), a member of the herpesvirus family*, causes the common childhood
illness varicella or chicken pox. Reactivation of the virus later in life causes
herpes* zoster, commonly known as shingles. Vaccines* are available that
prevent or ameliorate (reduce) the symptoms of both diseases.
Varicella or chicken pox is a highly contagious* disease caused by the
initial or primary infection with VZV. It is characterized by the appearance
of red, itchy spots on the skin. The spots progress to blisters and
eventually crust over.
Most people cannot contract varicella a second time because the body’s
immune system* makes protective antibodies*. However VZV remains in
the nerve tissues of the body in a dormant or inactive state. Years later—most
often after a person is 50 years of age—VZV can be reactivated in the form
of herpes zoster or shingles. Sometimes this reactivation occurs at a time of
emotional or physical stress. Shingles usually appears first as one or more
local areas of intense pain, followed by a red rash or blisters. Sometimes,
especially in the elderly, shingles causes nerve damage that can result in severe
pain called post-herpetic neuralgia that may last for months or years.