After you get chickenpox, the virus remains inactive (becomes dormant) in certain nerves in the body. Shingles occurs after the virus becomes active again in these nerves years later.
The reason the virus suddenly becomes active again is not clear. Often only one attack occurs.
Shingles may develop in any age group, but you are more likely to develop the condition if:
You are older than 60
You had chickenpox before age 1
Your immune system is weakened by medications or disease
If an adult or child has direct contact with the shingles rash and did not have chickenpox as a child or a chickenpox vaccine, they can develop chickenpox, not shingles.
The first symptom is usually one-sided pain, tingling, or burning. The pain and burning may be severe and is 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 belly area or chest.
The rash may involve the face, eyes, mouth, and ears.
Other symptoms may include:
Fever and chills
General ill feeling
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)
Loss of eye motion
Signs and tests
Your health care provider can make the diagnosis by looking at your skin and asking questions 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 that causes shingles.
Blood tests may show an increase in white blood cells and antibodies to the chickenpox virus, but they cannot confirm that the rash is due to shingles.
Your health care 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. Acyclovir, famciclovir, and valacyclovir may be used.
The medications should be started within 72 hours of when you first feel pain or burning. It is best to start taking them before the blisters appear. The drugs are usually given in pill form, and in high doses. 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 drugs do not work in all patients.
Other medicines may include:
Antihistamines to reduce itching (taken by mouth or applied to the skin)
Zostrix, a cream containing capsaicin (an extract of pepper) that may reduce the risk of postherpetic neuralgia
Cool wet compresses can be used to reduce pain. Soothing baths and lotions, such as colloidal oatmeal bath, starch baths, or calamine lotion, may help to relieve itching and discomfort.
Resting in bed until the fever goes down is recommended.
Keep the skin clean.
Do not reuse contaminated items.
Wash nondisposable items in boiling water or disinfect them before using them again
You may need to stay away from people while the sores are oozing to avoid infecting those who have never had chickenpox -- especially pregnant women.
Herpes zoster usually clears up 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.
Postherpetic neuralgia is more likely to occur in people over age 60. It occurs when the nerves have been damaged after an outbreak of shingles. Pain ranges from mild to very severe.
Complications may include:
Another attack of shingles
Bacterial skin infections
Blindness (if shingles occurs in the eye)
Infection, including encephalitis or sepsis (blood infection) in persons with a weakened immune system
Ramsay Hunt syndrome if shingles affects the nerves in the face
Calling your health care provider
Call your health care 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.
Avoid touching the rash and blisters on persons with shingles or chickenpox if you have never had chickenpox or the chickenpox vaccine.
A herpes zoster vaccine is available. It is different than the chickenpox vaccine. Older adults who receive the herpes zoster vaccine are less likely to have complications from shingles.
The United States Advisory Committee on Immunization Practices (ACIP) has recommended that adults older than 60 receive the herpes zoster vaccine as part of routine medical care.
Warts, herpes simplex, and other viral infections. In: Habif TP, ed. Clinical Dermatology. 5th ed. St. Louis, Mo: Mosby Elsevier; 2009:chap 12.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington; and Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.