Zoster / Shingles
Shingles — also known as herpes zoster — is a viral infection that causes a painful rash.
Shingles is caused by the varicella-zoster virus, the same virus that causes chickenpox. After you've had chickenpox, the virus lies dormant in your nerves. Years later, the virus may reactivate as shingles.
Although painful, typically shingles isn't a serious condition. Sometimes, however, the rash can lead to a debilitating complication called postherpetic neuralgia. This condition causes the skin to remain painful and sensitive to touch for months or even years after the rash clears up.
Early treatment can help shorten a shingles infection and reduce the risk of complications.
Shingles is a second eruption of the varicella-zoster virus — the same virus that causes chickenpox.
Varicella-zoster is part of a group of viruses called herpes viruses, which includes the viruses that cause cold sores and genital herpes. Many of these viruses can lie hidden in your nervous system after an initial infection and remain dormant for years before causing another infection.
Anyone who's had chickenpox may develop shingles. If your immune system doesn't destroy the entire virus during the initial infection, the remaining virus can enter your nervous system and lie hidden for years. Eventually, it may reactivate and travel along nerve pathways to your skin — producing shingles.
The reason for the encore is unclear. Shingles is more common in older adults and those who have weak immune systems.
About one in 10 healthy adults who've had chickenpox eventually develop shingles, usually after age 50. Most people develop shingles only once, but recurrences in other areas are possible.
A person with shingles can pass the varicella-zoster virus to anyone who hasn't had chickenpox before. This usually occurs through direct contact with the open sores of the shingles rash. Once infected, the person will develop chickenpox, however, not shingles. The infection can be serious for certain groups of people with immune system deficiencies.
Until the shingles blisters scab over, avoid physical contact with:
- Anyone who's never had chickenpox
- Anyone who has a weak immune system
- Pregnant women (A chickenpox infection can be dangerous for a developing baby.)
When to seek medical advice:
Consult your doctor as soon as you notice signs or symptoms of shingles. Prompt treatment can help shorten the infection and reduce the risk of complications.
Treatment is especially important when a rash develops near your eyes. An untreated rash in this area could lead to an infection of your cornea, which may cause temporary or permanent blindness.
The signs and symptoms of shingles may include:
- Pain, burning, tingling, itching, numbness or extreme sensitivity in a certain part of the body
- A red rash with fluid-filled blisters that begins a few days after the pain
- Upset stomach
Typically, the shingles rash occurs on only one side of the body. It often appears as a band of blisters that wraps from the middle of your back around one side of your chest to your breastbone, following the path of the nerve where the virus had been dormant.
Sometimes, the shingles rash occurs around one eye or on one side of the neck or face.
Although the shingles rash may resemble chickenpox, the virus typically causes more pain and less itching the second time around.
For about one in five people who develop shingles, the pain continues in the same spot long after the blisters have cleared. This condition is known as postherpetic neuralgia.
When you have postherpetic neuralgia, damaged nerve fibers send confused and exaggerated messages of pain from your skin to your brain. This leaves the affected area of skin sensitive to even the slightest touch. For some people, the brush of
clothing or a breeze can be excruciatingly painful.
Pain medication, antidepressants or anticonvulsant medications may help provide relief until the pain subsides.
Shingles can also lead to other complications, including inflammation of the brain (encephalitis) and other neurological problems. If shingles occurs on your face, it can cause hearing problems and temporary or permanent blindness. Loss of facial movement (paralysis) is possible as well. If blisters aren't properly treated, bacterial skin infections are another potential problem.
Although an episode of shingles usually heals on its own within a few weeks, prompt treatment can ease pain, speed healing and reduce the risk of complications. Complications are more likely for people who have weak immune systems and people older than age 65.
Doctors typically prescribe oral antiviral medications such as acyclovir (Zovirax), valacyclovir (Valtrex) or famciclovir (Famvir) to treat shingles — preferably beginning within 48 to 72 hours of the first sign of the shingles rash. Sometimes, antiviral medications are combined with corticosteroids to reduce swelling and pain.
If the pain is severe — particularly if you develop postherpetic neuralgia — your doctor may prescribe painkillers. Sometimes tricyclic antidepressants or certain anticonvulsants are helpful. A topical ointment called capsaicin (Zostrix, Zostrix-HP) or a skin patch that contains the pain-relieving medication lidocaine may be soothing as well.
The varicella virus vaccine (Varivax) — approved by the Food and Drug Administration in 1995 — has become a routine childhood immunization, given between ages 12 months and 18 months. The vaccine is also recommended for older kids and adults who've never had chickenpox.
The varicella virus vaccine prevents chickenpox for most people. If chickenpox does develop after vaccination, it's typically less severe.
The Food and Drug Administration (FDA) has also approved a vaccine (Zostavax) to help prevent shingles in adults age 60 and older. In one study involving thousands of participants, the shingles vaccine reduced the overall risk of shingles by about 50 percent for adults age 60 and older. For adults ages 60 to 69, the vaccine reduced the risk of shingles by 64 percent.
The shingles vaccine is given as a single injection, preferably in the upper arm. The most common side effects are redness, pain and swelling at the injection site, itching and headache.