Shingles is a disease caused by the varicella-zoster virus - the same virus that causes chickenpox.
After you have chickenpox, the virus stays in your body. It may not cause problems for many years. As you get older, the virus may reappear as shingles. Although it is most common in people over age 50, anyone who has had chickenpox is at risk.
You can't catch shingles from someone who has it. However, if you have a shingles rash, you can pass the virus to someone who has never had chickenpox. This would usually be a child, who could get chickenpox instead of shingles. The virus spreads through direct contact with the rash, and cannot spread through the air.
Early signs of shingles include burning or shooting pain and tingling or itching, usually on one side of the body or face. The pain can be mild to severe. Rashes or blisters appear anywhere from one to 14 days later. If shingles appears on your face, it may affect your vision or hearing. The pain of shingles may last for weeks, months, or even years after the blisters have healed.
There is no cure for shingles. Early treatment with medicines that fight the virus may help. These medicines may also help prevent lingering pain.
A vaccine may prevent shingles or lessen its effects. The vaccine is recommended for people 60 or over. In some cases doctors may give it to people ages 50 to 59.
The shingles vaccine is a preventive therapy and not a treatment for those who already have shingles or postherpetic neuralgia.
Immunization with the chickenpox vaccine can protect people from getting chickenpox. People who have been vaccinated against chickenpox are probably less likely to get shingles because the weak, “attenuated” strain of virus used in the chickenpox vaccine is less likely to survive in the body over decades.
Anyone who had previously had chickenpox is at risk for shingles. About 25 percent of all adults, mostly otherwise healthy, will get shingles during their lifetime, usually after age 50. The incidence increases with age so that shingles is 10 times more likely to occur in adults over 60 than in children under 10.
People with compromised immune systems, a natural consequence of aging or from use of immunosuppressive medications such as prednisone, are at increased risk of developing shingles. Immune-suppressive drugs are used to treat serious illnesses such as cancer or from chemotherapy or radiation treatment, or from infection with HIV.
Some individuals can also have re-eruptions and some, particularly those with significantly impaired immunity from drugs and diseases, may have shingles that spread over the body.
Younger individuals whose mothers had chickenpox late in pregnancy—5 to 21 days before giving birth—or who had chickenpox in infancy have an increased risk of pediatric shingles. Sometimes these children are born with chickenpox or develop a typical case within a few days.
Most people who get shingles have it only once, but it is possible for the outbreak to appear again.
Most adults in the United States have had chickenpox, even if it was so mild as to pass unnoticed, and they are at risk for developing shingles later in life. In the original exposure to chickenpox, some of the virus particles settle into nerve cells of groups of other nerve cells that connect parts of the nervous system, where they remain for many years in an inactive, hidden form.
When the chickenpox virus reactivates, it spreads down the long nerve fibers that extend from the sensory cell bodies to the skin. As the virus multiplies, the telltale rash erupts. With shingles, the nervous system is more deeply involved than it was during the bout with chickenpox, and the symptoms are often more complex and severe.
The first symptom of shingles is often burning or tingling pain, or itch, generally in a band-like distribution on one side of the body, i.e., around the waist, chest, stomach, or back. Shingles pain can be mild or intense. Some people have mostly itching; some feel severe pain from the gentlest touch, such as the weight of bed linens or clothing. A few people may have general symptoms of a viral infection, like fatigue, fever, and headache.
After several days or up to two weeks after the first symptoms are felt, a rash of fluid-filled blisters (vesicles) appears. These are similar to chickenpox but occur in a cluster rather than scattered over the body. The number of vesicles is variable. Some rashes merge and produce an area that looks like a burn. Other people may have just a few small scattered lesions. The clusters most often appear in a band called a dermatome, which contains nerves that branch out from the virus-affected nerve root exiting the spine. The second most common location is on one side of the face around the eye and on the forehead. However, shingles can involve any part of the body, including internal organs.
Currently there is no cure for shingles, but attacks can be made less severe and shorter by using prescription antiviral drugs as soon as possible after symptoms begin. Early treatment can reduce or prevent severe pain and help blisters dry faster. Antiviral drugs can reduce by about half the risk of being left with postherpetic neuralgia, which is chronic pain that can last for months or years after the shingles rash clears.
Doctors recommend starting antiviral drugs at the first sign of the shingles rash, or if the telltale symptoms indicate that a rash is about to erupt. Other treatments to consider are anti-inflammatory corticosteroids such as prednisone. These are routinely used when the eye or other facial nerves are affected.
Most people with shingles can be treated at home.
People with shingles should also try to relax and reduce stress; eat regular, well-balanced meals; and perform gentle exercises, such as walking or stretching to keep active and stop thinking about the pain. Placing a cool, damp washcloth on the blisters—but not when wearing a topical cream or patch—can help blisters dry faster and relieve pain. Keeping the area clean can help avoid a secondary bacterial infection.
For most healthy people who receive treatment soon after the outbreak of blisters, the lesions heal, the pain subsides within 3 to 5 weeks, and the blisters often leave no scars.
However, shingles is a serious threat in immunosuppressed individuals — for example, those with HIV infection or who are receiving cancer treatments that can weaken their immune systems. People who receive organ transplants are also vulnerable to shingles because they are given drugs that suppress the immune system.
A person with a shingles rash can pass the virus to someone, usually a child, who has never had chickenpox, but the child will develop chickenpox, not shingles. A person with chickenpox cannot communicate shingles to someone else. Shingles comes from the virus hiding inside the person's body, not from an outside source.