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 can develop 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.
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. Most adults with the dormant virus never experience an outbreak of shingles or any further problems.
However, in some individuals, it may reactivate multiple times.
Shingles is most common in people over the age of 50 years. However, the virus may reappear in people of all ages who have previously had chickenpox.
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.
Symptoms of shingles include pain, tender skin, and a rash, usually on one side of the body.
Pain is the most common symptom of shingles.
This can be a constant dull, burning, or gnawing pain, or sharp, stabbing pain that comes and goes.
There may also be a blistering skin rash.
This 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. This is why infection causes isolated skin lesions, rather than a body-wide rash, and nerve pain.
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.
Between 1 and 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.
If shingles affects the eye, this is called optical shingles. The virus invades an ophthalmic nerve and causes painful eye inflammation and temporary or permanent loss of vision.
New blisters may appear 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 within 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 include:
muscle pain and weakness
difficulties with urination
swollen glands (lymph nodes)
Rarely, shingles can lead to pneumonia, brain inflammation, or encephalitis, or death. This usually happens in people who have an impaired immune system.
If the rash affects areas of the face, symptoms may include:
difficulty moving some facial muscles
loss of eye motion
problems with taste
Most people do not experience any complications with shingles, but there is the potential for the following long-lasting effects:
postherpetic neuralgia (PHN), affecting 10 to 20 percent of people with shingles
peripheral motor neuropathy occurs in 5 to 10 percent of cases
encephalitis, or inflammation of the brain
transverse myelitis, or inflammation of the spinal cord
white patches due to loss of pigment in the rash area
Ramsay Hunt syndrome
What is causing my rash?
A rash is a widespread eruption of skin lesions
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 had 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.