Shingles is an infection of an individual nerve and the skin surface that is supplied by the nerve; it is caused by the varicella-zoster virus - the same virus that causes chickenpox.
Anyone who has recovered from chickenpox, child or adult, can get shingles.
There are an estimated 1 million cases of shingles each year in the United States, with 1 in 3 people developing shingles during their lifetime.
Contents of this article:
Fast facts on shingles
Here are some key points about shingles. More detail and supporting information is in the main article.
- Each year in the U.S., there are an estimated 1 million cases of shingles
- Around 1 in 3 people will develop shingles during their lifetime
- Shingles is a painful infection of the nerve supplying an area of skin and is accompanied by a localized skin rash
What is shingles?
Varicella-zoster (shingles) virus belongs to a group of viruses called herpesviruses.
Shingles is caused by the same virus that causes chickenpox. After recovery from chickenpox, the virus remains in the body and lies dormant in the central nervous system.
Varicella-zoster virus belongs to a group of viruses called herpes viruses, which is why shingles is also known as herpes zoster.
All herpes viruses can hide in the nervous system where they can remain almost indefinitely.
Given the right conditions, the herpes zoster virus can "reactivate" (or wake up from hibernation) and travel down nerve fibers to cause a new active infection.
The blistering skin rash associated with shingles usually appears in one or more distinct bands, called dermatomes. It may also appear on the face in a band, or break out on a quarter of the face.
These dermatomes correspond to a single sensory nerve, which is why infection causes isolated skin lesions rather than a body-wide rash and nerve pain.
It is not possible to have shingles if you have never been exposed to chickenpox or the varicella virus that causes it. Once exposed, the virus can lay dormant for years. In fact, the inactive virus may never cause any problems. However, in some individuals, it may reactivate multiple times.
Shingles is most common in people over the age of 50; about half of all cases occur in men and woman aged 60 or over. However, the virus may reappear in people of all ages who have previously had chickenpox.
Most adults with the dormant virus never experience an outbreak of shingles.
Causes of shingles
In most shingles cases, there is no known reason why the varicella-zoster virus begins multiplying. One suggestion is that shingles occurs when something weakens the immune system, prompting the virus to reactivate.
Some possible triggers for shingles include:
- Diseases - including certain cancers and HIV/AIDS
- Cancer treatments - chemotherapy and radiation therapy lower resistance to disease
- Stress or trauma - psychological and emotional stressors
- Medications - immunosuppressive drugs; after a transplant, a high percentage of patients develop shingles
- Children - youngsters whose mothers had chickenpox late in pregnancy or had chickenpox in infancy themselves
Symptoms of shingles
Symptoms of shingles include pain, tender skin, and a rash, usually on one side of the body.
The most common symptom of shingles is pain - a constant dull, burning, or gnawing pain, or sharp, stabbing pains that come and go. Other common symptoms include tender skin and a blistering rash.
Typically, shingles takes the following course:
- Acute pain, tingling, numbness, and itching on a specific part of the skin, on a single side of the body.
- 1-5 days after the pain begins, a rash appears.
- Red blotches emerge that develop into itchy fluid-filled blisters.
- The rash looks like chickenpox but only on the band of skin supplied by the affected nerve.
- The rash may involve the face, eyes, mouth, and ears in some cases.
- Sometimes the blisters merge, forming a solid red band that looks like a severe burn.
- In rare cases (among people with weakened immune systems) the rash may be more extensive and look similar to a chickenpox rash.
- Shingles can affect the eye, called optical shingles. The virus invades an ophthalmic nerve and causes painful eye inflammation and temporary or permanent loss of vision.
- New blisters may arise for up to a week.
- Inflammation might be caused in the soft tissue under and around the rash.
- People with lesions on the torso may feel spasms of pain at the gentlest touch.
- The blisters will gradually dry up and form scabs or crusts, in 7-10 days. At this point, the rash is no longer considered infectious.
- Minor scarring may occur where the blisters have been.
- A shingles episode normally lasts 2-4 weeks.
In some cases, there is a rash but no pain; or, no visible rash but a band of pain.
Other symptoms of shingles can include:
- Muscle pain and weakness
- Upset stomach
- Difficulties with urination
- Joint pain
- Swollen glands (lymph nodes)
- Rarely, shingles can lead to pneumonia, brain inflammation (encephalitis), or death. This usually happens in people who have an impaired immune system.
If the rash effects areas of the face, symptoms may include:
- Difficulty moving some facial muscles
- Drooping eyelids (ptosis)
- Hearing loss
- Loss of eye motion
- Problems with taste
- Vision problems
Most people do not experience any complications with shingles, but there is the potential for the following long-lasting effects:
- Postherpetic neuralgia (PHN) - occurs in 10-20 percent of shingles patients
- Peripheral motor neuropathy - occurs in 5-10 percent of cases
- Skin infection
- Encephalitis (inflammation of the brain)
- Transverse myelitis (inflammation of the spinal cord)
- White patches due to loss of pigment in the rash area
- Ramsay Hunt syndrome
- Eye problems
Diagnosis of shingles
Shingles can be diagnosed by a doctor based upon the distinctive appearance and distribution of the rash along a dermatome.
In cases where diagnosis is unclear, shingles can be confirmed by testing a swab of fluid from the blisters or blood for antibodies to the varicella-zoster virus.
Treatment of shingles14
There is currently no way to eliminate the shingles virus from the body, but several measures can be taken to ease symptoms:
- Keep the rash dry and clean to reduce risk of infection.
- Loose-fitting clothing will feel more comfortable.
- Rub-on antibiotic creams or adhesive dressings are not advised as they can slow the healing process.
- If the rash needs to be covered, a non-adherent dressing should be used to prevent aggravating the skin.
- Calamine lotion can soothe and relieve the itching.
- Antihistamines can sometimes be useful to prevent itching at night.
Painkilling medication may be prescribed by a doctor to ease the pain caused by shingles.
In some cases, antiviral medicine may be prescribed to help stop the virus multiplying, and to reduce severity and duration.
Before the blisters develop and after the crusts form, the person is not contagious.
Shingles cannot be passed from one individual to another. However, the varicella-zoster virus can be spread from a person with shingles at the active stage to someone who has never suffered from chickenpox.
In these cases, the infected individual would get chickenpox, not shingles.
Shingles is not spread through coughing or sneezing but through direct contact with fluid from the blisters. Before the blisters develop and after the crusts form, the person is not contagious.
Shingles is less contagious than chickenpox. The risk of spreading the virus is low if the rash is covered.
Immunization with the varicella vaccine (chickenpox vaccine) is now recommended and routine in America. It is a two-dose vaccine, given once between 12 and 15 months and again between 4 and 6 years old.Shingles vaccine
The Zostavax vaccine for varicella-zoster is approved for people over 50 who have had chickenpox. As a result, the number of shingles cases has dropped by 50 percent.
Some people should not get the shingles vaccine, or should discuss it with their physician; including:
- 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
Shingles typically resolves within 2-4 weeks and the prognosis is excellent for young healthy individuals who develop shingles.
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, the majority of which occur in older adults and those who are immunocompromised.