Shingles is an infection caused by the same virus that causes chicken pox. This virus is called the varicella zoster virus. Even after chicken pox blisters heal, the varicella zoster virus stays in the body for life. If it becomes active again, it causes shingles. Two out of every 10 people will get shingles in their lifetimes.
After chicken pox blisters heal, the varicella zoster virus that caused them stays in your body in certain nerve cells. It may be there for many years without causing a problem. Sometimes it becomes active again. When it becomes active again, the virus travels down the nerve fibers that extend to your skin, where a rash develops. This rash can be quite painful.
You get shingles from the varicella zoster virus after it has been in your body for years. The virus can first enter your body if you have been exposed to someone who has chicken pox. Even if you never get symptoms, you can still have the virus in your body. (More than 9 out of 10 people over the age of 15 in Canada have had chicken pox.)
Shingles is most common in people over age 50 and in those who have a weak immune system. Some other conditions that can also weaken the immune system are:
- HIV (AIDS virus) infection
- Cancer, or some cancer treatments
- Certain drugs you take after an organ transplant
A person who has had repeated shingles outbreaks should consult a health care provider to be checked for other health problems.
Shingles has 2 stages:
- The prodromal stage -- symptoms occur about 2 to 5 days before the rash appears.
- The eruptive stage -- skin rash (lesions) appears.
Symptoms that may appear during the prodromal stage include:
- Numbness, tingling, itching, or pain in the place where the rash is about to appear
- Fever, sometimes with chills
The main symptoms of the eruptive stage involve a skin rash, which usually involves:
- Redness of the skin followed by swelling or bumps.
- From the bumps, blisters then form that contain clear fluid. The blisters become pustules (pimple-like sores) and crusts (scabs).
- The rash almost always appears in a band or patch on just one side of the body.
- Any part of the body can be involved, including the back, chest, abdomen, arms, legs, or face.
- Symptoms may range from only mildly bothersome to itchy to really painful.
- New blisters may continue to appear for up to 5 days.
- Within 14 days, a scab forms.
- The rash usually goes away in about 3 to 5 weeks.
It is often hard to tell if you have shingles during the prodromal stage, before the rash appears. That's because the symptoms of other conditions can look like shingles symptoms. Once the rash appears, however, you need to go to a healthcare provider as soon as you can. Treating shingles within 3 days after the rash appears can help to lessen the duration and severity of symptoms.
Your healthcare provider will take a medical history. He or she will want to know:
- When your rash started
- Where it is on your body
- About any other symptoms you have had, such as a fever or numb or tingling feelings elsewhere on your skin
Your healthcare provider will also examine you.
- He or she will look at your rash to make sure it hasn't been caused by something besides shingles.
- In some cases, your provider will take a swab of fluid from one of your blisters. A laboratory can test this sample to see if it contains the varicella zoster (shingles) virus.
There are 3 goals of treatment for shingles:
- Provide comfort and relieve symptoms, such as pain and itching.
- Shorten the duration of symptoms.
- Lessen the duration of post-herpetic neuralgia, a serious complication of shingles.
To achieve these goals, shingles is most often treated with:
- Antiviral prescription drugs that fight the virus and reduce the time that it is active
- Pain relievers and anti-inflammatories, either by prescription or over-the-counter
Treatment for shingles should begin within 3 days of the outbreak of the rash. If you delay treatment or don't get treatment at all, you can increase the risk that shingles will lead to complications.
In addition to treating shingles with medicine, there are steps you can take to improve comfort, reduce pain, and help the shingles rash to heal.
- Apply clean, cool cloths or dressings to your rash twice a day.
- Rinse the rash with cool water twice a day.
- Avoid using hot water to rinse the rash; heat may lead to further itching.
- Cover your rash with loose-fitting gauze or cloth to keep it clean.
- Wear loose-fitting clothing and as little clothing as necessary.
- To prevent bacterial infection, don't scratch or rub.
If you delay getting treatment for shingles, or don't get treatment at all, you can increase your risk for complications from shingles.
The most common complications you could get include:
- Post-herpetic neuralgia. This is pain that may last for months or years after shingles heals. It can be mild or severe. This condition is the most frequent complication of shingles. Nerve damage that results from the shingles infection causes this pain. Older people are more likely than younger people to get post-herpetic neuralgia after shingles. Also, the more severe the pain when shingles first starts, the greater the chance a person will develop post-herpetic neuralgia. For many patients, early treatment with antiviral drugs can help lessen the duration of this condition. Prescription drugs that help relieve pain often are used as well.
- Bacterial infections. Scratching the rash may damage the skin and allow skin germs (for example, strep or staph bacteria) to infect the shingles rash, making it worse. If you have shingles and your rash is not healing or is getting worse, see your healthcare provider right away
Some people have weakened immune systems that allow the virus to spread all over the body or to internal organs. This can happen if you have certain diseases, such as HIV, or are getting treatment with certain drugs, such as:
- Drugs that fight cancer
- Drugs that help prevent organ rejection after a transplant
It is very important for people with a weak immune system to see their healthcare providers right away if they think they have shingles.