Shingles: Why the Chickenpox Virus Returns, Its Complications, and the Vaccine

Shingles (herpes zoster) is an infection that causes a painful rash. It is caused by the varicella-zoster virus (VZV) — the same virus that causes chickenpox. After chickenpox, the virus stays in your body, sometimes quietly for many years; as you get older, it can reactivate as shingles.

Is it contagious?

• You can't catch shingles from someone else.
• But someone who hasn't had chickenpox can catch chickenpox by direct contact with the fluid from a shingles rash. The risk is low if the rash is covered.
• People with shingles can't spread the virus before the blisters appear or after the rash crusts.

Who is at risk

Anyone who has had chickenpox can get shingles, and the risk rises with age; it is most common over 50. People with weakened immune systems are at higher risk — including those with immune diseases such as HIV, certain cancers, or medicines that weaken immunity, such as steroids and drugs taken after an organ transplant. Infection or stress can also weaken immunity and raise the risk. Getting shingles more than once is rare but possible.

Symptoms

• Early: burning or shooting pain, tingling or itching, usually on one side of the body or face; the pain can be mild to severe.
• Days later: a rash of blisters that usually scab over in 7 to 10 days — typically a single stripe around the left or right side of the body, or on one side of the face. Rarely, mostly in people with weak immunity, it spreads more widely and can look like chickenpox.
• Some people also have fever, headache, chills or an upset stomach.

Complications

• Postherpetic neuralgia (PHN), the most common: severe pain where the rash was. It usually eases within weeks or months, but for some it lasts years and disrupts daily life.
• Vision loss if shingles affects the eye — temporary or permanent.
• Hearing or balance problems, and facial muscle weakness, if it affects the ear — temporary or permanent.
• Very rarely, pneumonia, brain inflammation (encephalitis) or death.

Diagnosis and treatment

A provider can usually diagnose shingles from your history and the rash, sometimes sending a scraping or fluid sample to a lab.

There is no cure, but antiviral medicines can make the attack shorter and milder and may help prevent PHN — they work best within 3 days of the rash appearing, so contact your provider quickly. Pain relievers help with pain; a cool washcloth, calamine lotion and oatmeal baths ease itching.

Prevention

The Shingrix vaccine, given in two doses, helps prevent shingles and its complications. The Centers for Disease Control and Prevention recommends it for healthy adults 50 and older, and your provider may recommend it if you are over 19 with a weakened immune system.

If you have shingles, help protect others:

• stay away from people with weakened immunity, people who haven't had chickenpox or the chickenpox vaccine — especially if pregnant — and premature or low birth weight babies;
• keep the rash covered, don't touch or scratch it, and wash your hands often.

Sources

Based on "Shingles," MedlinePlus, U.S. National Library of Medicine, with information from the Centers for Disease Control and Prevention; a work of the United States government in the public domain.