Causes Of Shingles

Shingles is caused by the varicella-zoster virus — the same virus that causes chickenpox. Anyone who's had chickenpox may develop shingles. After you recover from chickenpox, the virus can enter your nervous system and lie dormant for years.

Eventually, it may reactivate and travel along nerve pathways to your skin — producing shingles. But, not everyone who's had chickenpox will develop shingles.

The reason for shingles is unclear. But it may be due to lowered immunity to infections as you grow older. Shingles is more common in older adults and in people who have weakened immune systems.

Varicella-zoster is part of a group of viruses called herpes viruses, which includes the viruses that cause cold sores and genital herpes. Because of this, shingles is also known as herpes zoster. But the virus that causes chickenpox and shingles is not the same virus responsible for cold sores or genital herpes, a sexually transmitted infection.

Are You Contagious?

A person with shingles can pass the varicella-zoster virus to anyone who isn't immune to chickenpox. This usually occurs through direct contact with the open sores of the shingles rash. Once infected, the person will develop chickenpox, however, not shingles.

Chickenpox can be dangerous for some people. Until your shingles blisters scab over, you are contagious and should avoid physical contact with anyone who hasn't yet had chickenpox or the chickenpox vaccine, especially people with weakened immune systems, pregnant women and newborns.

RISK FACTORS

Anyone who has ever had chickenpox can develop shingles. Most adults in the United States had chickenpox when they were children, before the advent of the routine childhood vaccination that now protects against chickenpox.

Factors that may increase your risk of developing shingles include:

Being older than 50. Shingles is most common in people older than 50. The risk increases with age. Some experts estimate that half the people age 80 and older will have shingles.

Having certain diseases. Diseases that weaken your immune system, such as HIV/AIDS and cancer, can increase your risk of shingles.

Undergoing cancer treatments. Radiation or chemotherapy can lower your resistance to diseases and may trigger shingles.

Taking certain medications. Drugs designed to prevent rejection of transplanted organs can increase your risk of shingles — as can prolonged use of steroids, such as prednisone.

Vaccine

Vaccines can prevent both chicken pox and shingles.

Chickenpox Vaccine

Immunization with the varicella vaccine (chickenpox vaccine) is now recommended and routine in the U.S. It is a two-dose vaccine, given once between the age of 12 and 15 months and again between 4 and 6 years.

Shingles Vaccine

The Centers for Disease Control and Prevention (CDC) recommends the Zostavax vaccine for people aged 60 years and above. This age group has the highest risk of getting shingles and of experiencing a complication.

Since vaccination started in children, the number of shingles cases has dropped significantly.

Some people should not have the shingles vaccine, or they should discuss it first with their physician.

These include:

•        anyone who has ever had a severe allergic reaction to gelatin, the antibiotic neomycin, or any other component of shingles vaccine

•        anyone with a weakened immune system

•        women who are or might be pregnant

Prognosis

Shingles typically resolves within 2 to 4 weeks, and most young, healthy individuals make a full recovery.

Approximately 1-4 percent of people who develop shingles require hospitalization for complications, and 30 percent of those have impaired immune systems.

It is estimated that there are about 96 deaths per year directly related to the varicella-zoster virus. Most which occur in older adults and those who are immunocompromised.