I’m a healthy 55-year-old man. Should I get the shingles vaccine?

DEAR DOCTOR K:

I’m a healthy 55-year-old man. Should I get the shingles vaccine? And while you’re at it, what exactly is shingles?

DEAR READER:

Shingles is a condition that results in a rash and pain. It is caused by the same virus (called VZV) that causes chickenpox. After a case of chickenpox, the virus can lie dormant inside your nerves for decades. By “dormant,” I mean that it is not multiplying — it just lies there inside the nerve cells.

Some people get infected with the virus without knowing it — that is, without getting chickenpox. That happened to me: I never had chickenpox, but I had shingles as an adult. The virus gets into the body, infects some nerves and remains inactive. People catch the virus from other people, usually during childhood.

Shingles occurs when the virus become reactivated — when it starts to multiply. We don’t really understand what causes “sleeping” viruses like this one to become reactivated. The infected nerves, and the skin the nerves go to, become inflamed. This causes a rash that often contains little blisters, along with an unpleasant sensation in the area of the rash. More serious damage to the nerves leads to long-lasting pain known as postherpetic neuralgia.

Most patients describe the pain as “burning” or “stabbing.” It often gets worse when the skin touches something, even something as light as a shirtsleeve. The rash usually lasts a week to 10 days. If postherpetic neuralgia develops, the pain can be severe and last for months or sometimes years.

Most often, the painful rash of shingles occurs on the chest or abdomen, front or back. But it can also occur on the arms, legs and face. It typically appears on just one side of the body, looking like a red stripe. That stripe follows the path of the nerve that is infected.

Many experts recommend that all Americans ages 50 or older should get the shingles vaccine. That applies even if they’ve already had shingles, and even if they are not sure that they ever had chickenpox. The vaccine consists of a single shot in the upper arm.

Getting the vaccine does not guarantee that you won’t get shingles, but it does reduce your chances by 50 percent or more. And it does an even better job of reducing your risk of postherpetic neuralgia.

Because the shingles vaccine is made with a weakened — not dead — form of the virus, a small number of people develop a rash within a month or so of getting the vaccine. The vaccine should not be given to pregnant women, but few women age 50 and older become pregnant.

Not all health insurance policies cover the cost of the shingles vaccine. You may want to look into this in making the decision to get the vaccine.

The reason to consider getting the shingles vaccine is to reduce your risk of getting postherpetic neuralgia — by two-thirds! I’ve voted with my feet. I got the vaccine, because I’ve seen too many of my patients suffer from postherpetic neuralgia. (Even though I’ve had shingles once, you can get it again.) Chronic pain can disrupt a person’s life. If there’s a simple way to reduce your risk, why not do it?

(This column is an update of one that ran originally in October 2011.)