Shingles
Herpes zoster - shingles
Shingles is a painful, blistering skin rash. It is caused by the varicella-zoster virus, a member of the herpes family of viruses. This is the virus that also causes chickenpox.
A classical pattern for shingles. The infection follows a nerve root from the spine, along a rib, to the front of the chest. The area innervated by the nerve is called a dermatome.
Understanding the nerve distribution along the dermatomes is helpful in determining how certain diseases, such as shingles and some other neurological conditions, target one area of the body. The letter-number combinations show the relationship between each area and its corresponding sensory nerve. The vertebrae are classified as C for cervical, T for thoracic, L for lumbar, and S for sacral. The trigeminal nerve is the fifth cranial nerve, represented by V.
Shingles, or herpes zoster, is caused by the same virus that causes chickenpox. The virus can lie dormant in the body for many years and re-emerge as shingles. Shingles appear as a painful rash. It consists of red patches of skin with small blisters (vesicles) that look very similar to early chickenpox. Shingles usually clears in 2 to 3 weeks and rarely recurs.
A close-up picture of herpes zoster skin lesions. Four small blisters are shown with redness around them. These vesicles will break, crust over, scab, and finally heal.
This is a picture of herpes zoster (shingles) on the neck and cheek. Shingles are caused by the same virus that causes chickenpox. Outbreaks of shingles often follow the distribution of nerves in the skin. This distribution pattern is called a dermatome (see the dermatomes picture).
Shingles occurs more commonly on the chest and back, but can involve the arms and legs. The small blisters on this person's hand represent involvement of the dermatome innervated by the 7th cervical nerve. (See the Dermatomes picture.)
Herpes zoster (shingles) normally occurs in a limited area that follows a dermatome (see the dermatome picture). In individuals with damaged immune systems, herpes zoster may be widespread (disseminated), causing serious illness. Herpes zoster is caused by the same virus that causes chickenpox.
Causes
After you get chickenpox, your body does not get rid of the virus. Instead, the virus remains in the body but is inactive (becomes dormant) in certain nerves in the body. Shingles occurs after the virus becomes active again in these nerves after many years. Many people had such a mild case of chickenpox that they do not realize they have had the infection.
The reason the virus suddenly becomes active again is not clear. Often only one attack occurs.
Shingles can develop in any age group. You are more likely to develop the condition if:
- You are older than age 60
- You had chickenpox before age 1
- Your immune system is weakened by medicines or disease
If an adult or child has direct contact with the shingles rash and did not have chickenpox as a child or get the chickenpox vaccine, they can develop chickenpox, not shingles.
The same virus that made you itch and scratch from chickenpox when you were a child can come back to haunt you when you get older. You'll know it's come back by the painful, blistery rash it leaves on your skin. Shingles is caused by the varicella-zoster virus, the same virus that's responsible for chickenpox. Before there was a vaccine to prevent chickenpox, it was a very common childhood illness. After you have chickenpox, the virus can lie hidden in your body for years. Then when you get older, it can become active again. This time it's called shingles, not chickenpox. Doctors don't really know why the shingles virus reappears in some people but not others. If you're over age 60 or you have a weak immune system, your risk of getting the disease is higher. You can tell that it's shingles by the red, blistery patches on your skin, especially if you had chickenpox when you were young. Usually the rash is focused on your trunk area around your back, belly, and chest. You may also have blisters on your face. It will probably hurt, tingle, or burn, sometimes even before there is a rash. When the blisters break open, they'll dry out and form crusts. If you do have shingles, your doctor may prescribe an antiviral drug like acyclovir, famciclovir, or valacyclovir. These drugs fight the virus that causes shingles, but you need to start taking them within 24 hours after you start feeling the pain and burning of the rash for them to be effective. You may also get medicines to reduce swelling and relieve itching and pain. To ease really bothersome itching at home, soak in a soothing bath or gently rub calamine lotion on your skin. Most cases of shingles clear up within a couple of weeks. Sometimes, though, shingles can leave behind permanent nerve damage, called postherpetic neuralgia. The good news about shingles is that once it clears up, it's usually gone for good. But the pain, and nerve damage it causes, can sometimes linger. If you've had shingles and your pain isn't subsiding or your rash isn't clearing up, call your doctor. To avoid getting shingles, stay away from anyone who has either shingles or chickenpox, especially if you've never had chickenpox before. And get vaccinated against the varicella-zoster virus if you're over age 60.
Symptoms
The first symptom is usually pain, tingling, or burning that occurs on one side of the body. The pain and burning may be severe and are usually present before any rash appears.
Red patches on the skin, followed by small blisters, form in most people:
- The blisters break, forming small sores that begin to dry and form crusts. The crusts fall off in 2 to 3 weeks. Scarring is rare.
- The rash usually involves a narrow area from the spine around to the front of the abdomen or chest.
- The rash may instead involve the face, eyes, mouth, and ears.
Other symptoms may include:
- Fever and chills
- General ill feeling
- Headache
- Joint pain
- Swollen glands (lymph nodes)
You may also have pain, muscle weakness, and a rash involving different parts of your face if shingles affects a nerve in your face. The symptoms may include:
- Difficulty moving some of the muscles in the face
- Drooping eyelid (ptosis)
- Hearing loss
- Loss of eye motion
- Taste problems
- Vision problems
Exams and Tests
Your health care provider can make the diagnosis by looking at your skin and asking about your medical history.
Tests are rarely needed, but may include taking a skin sample to see if the skin is infected with the virus.
Blood tests may show an increase in white blood cells and antibodies to the chickenpox virus. But the tests cannot confirm that the rash is due to shingles.
Treatment
Your provider may prescribe a medicine that fights the virus, called an antiviral drug. This drug helps reduce pain, prevent complications, and shorten the course of the disease.
The medicines are most effective when started within 72 hours of when you first feel pain or burning. It is best to start taking them before the blisters appear. The medicines are usually given in pill form. Some people may need to receive the medicine through a vein (by IV).
Strong anti-inflammatory medicines called corticosteroids, such as prednisone, may be used to reduce swelling and pain. These medicines do not work in all people.
Other medicines may include:
- Antihistamines to reduce itching (taken by mouth or applied to the skin)
- Pain medicines
- Zostrix, a cream containing capsaicin (an extract of pepper) to reduce pain
Follow your provider's instructions about how to care for yourself at home.
Other measures may include:
- Caring for your skin by applying cool, wet compresses to reduce pain, and taking soothing baths
- Resting in bed until the fever goes down
Stay away from people while your sores are oozing to avoid infecting those who have never had chickenpox -- especially pregnant women.
Outlook (Prognosis)
Herpes zoster usually clears in 2 to 3 weeks and rarely returns. If the virus affects the nerves that control movement (the motor nerves), you may have temporary or permanent weakness or paralysis.
Sometimes the pain in the area where the shingles occurred may last from months to years. This pain is called postherpetic neuralgia.
It occurs when the nerves have been damaged after an outbreak of shingles. Pain ranges from mild to very severe. Postherpetic neuralgia is more likely to occur in people age 60 or over.
Possible Complications
Complications may include:
- Another attack of shingles
- Bacterial skin infections
- Blindness (if shingles occurs in the eye)
- Deafness
- Infection, including encephalitis or sepsis (blood infection) in people with a weakened immune system
- Ramsay Hunt syndrome if shingles affects the nerves of the face or ear
When to Contact a Medical Professional
Contact your provider if you have symptoms of shingles, particularly if you have a weakened immune system or if your symptoms persist or worsen. Shingles that affects the eye may lead to permanent blindness if you do not receive emergency medical care.
Prevention
Do not touch the rash and blisters on people with shingles or chickenpox if you have never had chickenpox or the chickenpox vaccine.
The shingles vaccine is different than the chickenpox vaccine. Older adults who receive the shingles vaccine are much less likely to have complications from the condition.
References
Dinulos JGH. Warts, herpes simplex, and other viral infections. In: Dinulos JGH, ed. Clinical Dermatology. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 12.
Whitley RJ. Chickenpox and herpes zoster (varicella-zoster virus). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 136.
Version Info
Last reviewed on: 12/4/2022
Reviewed by: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
