Shingles (herpes zoster) is a painful, blistering skin rash. It is caused by the varicella-zoster virus. This is the virus that also causes chickenpox.
Causes, incidence, and risk factors
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 after many years.
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 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 the chickenpox vaccine, they can develop chickenpox, not shingles.
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 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 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.
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.
The medicines 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 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 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) to reduce pain
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.
Do not touch 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.
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, Bethanne Black, and the A.D.A.M. Editorial team.