What is shingles?

Shingles is a viral infection that causes a painful rash. It’s an acute, painful inflammation of the nerve ganglia, with a skin eruption most commonly around the middle of the body. It’s caused by the same virus as chickenpox.

About 1 out of every 3 people in the US may develop shingles within their lifetime, and anyone who has had chickenpox may develop shingles. The risk of getting the disease increases as a person gets older.

Shingles can occur anywhere on your body. However, it most often develops as a stripe of blisters wrapped around the left or right side of your torso.

What causes shingles?

Shingles is caused by the varicella-zoster virus, the same virus that causes chickenpox. If you’ve had chickenpox, the virus will lie inactive in nerve tissue near your spinal cord and brain, which later in life may reactivate and manifest as shingles.

However, there are differences between how the chickenpox virus and the shingles virus exhibit their respective symptoms.

Chickenpox causes itchy blisters that normally start on your back, chest or face, then spread to the rest of your body. Shingles is a rash with shooting pain that usually shows up on your torso.

Who can get shingles?

Anyone who has had and has recovered from chickenpox can develop shingles, even children. However, the risk increases as people age and is most common in people 50 and older.

Additionally, there are those who are at a higher risk of developing shingles, such as:

  • Those with certain medical conditions that affect the immune system, like cancers such as leukemia or lymphoma, and human immunodeficiency virus (HIV).
  • People currently receiving immunosuppressive drugs, such as steroids and drugs administered after an organ transplant.

Most people who end up developing shingles usually only have one episode during their lifetime. However, having a second or even a third episode is not uncommon.

Shingles symptoms

Generally, there are two stages to the signs and symptoms of shingles: early symptoms and later-stage symptoms.

Early signs of shingles
The first signs and symptoms of shingles usually appear 1–5 days before any type of rash. People often have sensations in the area where the rash will develop, such as:

  • Itching
  • Tingling
  • Burning
  • Pain

Second stage of shingles
The shingles rash usually occurs in a single stripe around either the left or the right side of the body. In some cases, it occurs on one side of the face. And in very rare cases (normally among those with weakened immune systems), the rash can become more widespread and manifest similar to a chickenpox rash. Shingles can also affect a person’s eyes and cause a loss of vision.

Other symptoms of shingles
While the localized pain and rash are usually the most common signs and symptoms of shingles, others may include:

  • Fever
  • Chills
  • Headache
  • Upset stomach

What does shingles look like?

The shingles rash can look like a distinctive cluster of fluid-filled blisters, similar to chickenpox, but the rash is usually centrally located around the torso. Another common location is on one side of the forehead or around one eye, but shingles blisters have been known to occur anywhere on the body.

How do you get shingles?

While shingles itself can’t be passed from person to person, the virus that causes shingles, the varicella-zoster virus, can spread from someone with active shingles to cause chickenpox in another person who’s never had chickenpox or who has never received the chickenpox vaccine.

Is shingles infectious?

Yes. You can spread the varicella-zoster virus to people who’ve never had chickenpox and haven’t been vaccinated.

It’s spread through direct contact with fluid from the shingles rash blisters, and only when the rash is in the blister phase. A person is not contagious before blisters appear, and once the rash has developed “crusts,” a person is no longer infectious.

Until that point, it’s best to avoid being around pregnant women who may not have had chickenpox or the vaccine, those with weakened immune systems and newborns.

The good news is that there is a vaccine for shingles that can prevent most people from ever developing the virus.

Who should get the shingles vaccine?

According to the CDC, the recommended age to get vaccinated is 50 and older for healthy adults. And if you’re not sure when to get the shingles vaccine, you can even get it even if you’re unsure if you’ve had chickenpox.

The shingles vaccine, Shingrix, was licensed by the FDA in 2017. The CDC recommends two doses of Shingrix 2–6 months apart, and is the preferred vaccine for shingles.

How effective is the shingles vaccine?

The CDC recommends Shingrix. Shingrix is proven to reduce the chances of an outbreak by more than 90 percent in all age groups. It can also lower the chances of developing post-herpetic neuralgia.

Shingles vaccine side effects       

Side effects of the shingles vaccine are generally mild and usually go away in a few days. They can include:

  • Pain, swelling or redness at the injection site
  • Headache
  • Feeling tired
  • Muscle pain
  • Shivering
  • Fever
  • Stomach pain or upset stomach

Serious side effects from the shingles vaccine are rare.