Shingles is a viral infection that causes a painful rash. Although shingles can occur anywhere on your body, it most often appears as a single stripe of blisters that wraps around either the left or the right side of your torso.
Shingles is caused by the varicella-zoster virus — the same virus that causes chickenpox. After you've had chickenpox, the virus lies inactive in nerve tissue near your spinal cord and brain. Years later, the virus may reactivate as shingles.
While it isn't a life-threatening condition, shingles can be very painful. Vaccines can help reduce the risk of shingles, while early treatment can help shorten a shingles infection and lessen the chance of complications.
Shingles usually affect only a small section of one side of your body. These signs and symptoms may include:
- Pain, burning, numbness or tingling
- Sensitivity to touch
- A red rash that begins a few days after the pain
- Fluid-filled blisters that break open and crust over
- Sensitivity to light
Pain is usually the first symptom of shingles. For some, it can be intense. Depending on the location of the pain, it can sometimes be mistaken for a symptom of problems affecting the heart, lungs or kidneys. Some people experience shingles pain without ever developing the rash.
When to see a doctor
Contact your primary care doctor promptly if you suspect shingles, but especially in the following situations:
- The pain and rash occur near an eye. If left untreated, this infection can lead to permanent eye damage.
- You're 70 or older, because age significantly increases your risk of complications.
- You or someone in your family has a weakened immune system (due to cancer, medications or chronic illness).
- The rash is widespread and painful.
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 groups of people. Until your shingles blisters scab over, you are contagious and should avoid physical contact with:
- Anyone who has a weak immune system
- Pregnant women
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 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.
Shingles is usually diagnosed based on the history of pain on one side of your body, along with the telltale rash and blisters. Your doctor may also take a tissue scraping or culture of the blisters for examination in the laboratory.
There's no cure for shingles, but prompt treatment with prescription antiviral drugs can speed healing and reduce your risk of complications. These medications include:
- Acyclovir (Zovirax)
- Valacyclovir (Valtrex)
- Famciclovir (Famvir)
Shingles can cause severe pain, so your doctor also may prescribe:
- Anticonvulsants, such as gabapentin (Neurontin)
- Tricyclic antidepressants, such as amitriptyline
- Numbing agents, such as lidocaine, delivered via a cream, gel, spray or skin patch
- Medications that contain narcotics, such as codeine
Shingles generally lasts between two and six weeks. Most people get shingles only once, but it is possible to get it two or more times. Taking a cool bath or using cool, wet compresses on your blisters may help relieve the itching and pain. And, if possible, try to reduce the amount of stress in your life.
Two vaccines may help prevent shingles — the chickenpox (varicella) vaccine and the shingles (varicella-zoster) vaccine.
The varicella vaccine (Varivax) has become a routine childhood immunization to prevent chickenpox. The vaccine is also recommended for adults who've never had chickenpox. Though the vaccine doesn't guarantee you won't get chickenpox or shingles, it can reduce your chances of complications and reduce the severity of the disease.
The Food and Drug Administration has approved the use of the varicella-zoster vaccine (Zostavax) for adults age 50 and older. Like the chickenpox vaccine, the shingles vaccine doesn't guarantee you won't get shingles. But this vaccine will likely reduce the course and severity of the disease and reduce your risk of postherpetic neuralgia.
The shingles vaccine is used only as a prevention strategy, however. It's not intended to treat people who currently have the disease. The vaccine contains live virus and should not be given to people who have weakened immune systems.