In some people, shingles can cause serious side effects such as permanent vision loss. It may also lead to pneumonia, inflammation of the brain, and death, but these effects are rare.

Being older and having a weakened immune system increase a person’s risk of shingles. The Centers for Disease Control and Prevention (CDC) recommend that people over age 50 receive 2 doses of the shingles vaccine to help prevent the disease and its possible complications. The CDC also recommends the 2-dose vaccine for anyone aged 19 or older who has a weakened immune system.

Treatment can consist of antiviral and pain relief medications.

This article discusses the symptoms and dangers of shingles, as well as the increased risk of shingles in some populations. It also examines the treatment, when to see a doctor, and strategies to prevent complications and reduce the spread of the virus.

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Shingles — also called herpes zoster — is an infection that causes a painful rash. The cause of shingles is the varicella-zoster virus, the same virus that produces chickenpox.

After someone recovers from chickenpox, the virus remains in their body in an inactive form. If the virus reactivates later, it can cause shingles.

Approximately 33% of people in the United States will develop shingles in their lifetime. The infection affects an estimated 1 million people in the U.S. every year.

Learn more about shingles.

Symptoms

Symptoms can range from mild to severe and may include:

People often experience pain, tingling, or itching in an area of skin several days before the rash appears in that area. Typically, the rash occurs in a single stripe around the right or left side of the body, but sometimes it affects one side of the face. The rash usually scabs over in 7–10 days and clears up within 2–4 weeks.

In some people, shingles can be serious. If the rash appears near the eye, it may lead to permanent damage and even vision loss.

Another complication involves ongoing pain called postherpetic neuralgia (PHN). Approximately 10–18% of individuals who get shingles develop PHN, which manifests in the area where the rash occurred.

PHN may linger for months or years, causing some people to experience difficulties in performing daily activities such as dressing and cooking. Additionally, PHN can cause:

Very rare dangers of PHN include:

Severe complications can be fatal for some individuals.

Learn more about how shingles can affect the eye.

If an individual has had chickenpox, they are at risk of developing shingles. The risk increases with age, as half of shingles cases occur in people aged 60 and older.

Additionally, having a weakened immune system makes it harder for a person to fight all kinds of infections, including shingles. Factors that can harm immunity include:

Shingles poses a greater danger to older adults and to people who are pregnant or have weakened immune systems. The infection does not appear to be a serious threat in infants.

Older adults

An older adult has a higher risk of developing PHN than a younger person. This complication rarely happens in people younger than age 40.

People with weakened immune systems

According to a 2020 review, shingles is more severe in people with weakened immune systems. This group has a greater risk of several complications.

Individuals who are pregnant

People who are pregnant can develop shingles, but the condition does not increase the risk of fetal death. Also, transmission of the infection to the fetus is rare.

Despite this, shingles can cause significant complications in pregnant people, according to a case report from 2020. Even if a person receives treatment for shingles in the active stage, it is hard to substantially lower the risk of PHN.

Learn more about being pregnant and having shingles.

Infants

A 2013 case report states that shingles is rare in young children and even rarer in infants. The literature reports only occasional cases in infants. In all the cases, the shingles were not severe and the infant recovered quickly, without any complications.

Treatment involves taking antiviral medications, which target the virus that causes the infection.

Options include:

Treatment for symptoms may include either over-the-counter or prescription pain relievers and use of the following to help reduce itching:

If a person believes they may have shingles, they should contact a doctor as soon as possible. Treatment is more effective if it starts early.

In fact, beginning treatment 2–3 days after the rash appears can dramatically:

  • shorten the duration
  • reduce symptoms such as pain
  • decrease the risk of complications such as PHN

Even if someone has had shingles for more than 2–3 days, they should still consult a doctor because of the risk of complications.

People may be able to prevent complications of shingles in the following ways:

Limiting contact with rashes

Shingles spreads through direct contact with the fluid from rash blisters. The virus can spread to people who have not received the shingles vaccine and have never had chickenpox.

Even if a person has received the shingles vaccine, they may be at risk of developing the condition, although the risk is lower.

Additionally, people with a history of shingles may be at risk of reinfection. However, the risk is lower.

It is important to note that the virus cannot spread before the rash blisters appear or after they crust over.

The CDC offers the following recommendations to prevent the virus from spreading:

  • Cover the rash.
  • Wash hands frequently.
  • Avoid scratching or touching the rash.
  • Until the rash crusts over, avoid contact with:
    • premature or low weight infants
    • pregnant people who have never had the shingles vaccine or chickenpox
    • people with weakened immune systems

Chickenpox

When someone who has not had chickenpox or received the vaccine comes into contact with the herpes-zoster virus, they may develop chickenpox.

Vaccination

The recombinant zoster vaccine (Shingrix) is the best way to prevent shingles and its complications, including PHN. Two doses are more than 90% effective for protection in adults aged 50 and older who have healthy immune systems.

Immunity remains strong for at least the first 7 years after vaccination.

The vaccine is less effective in people with weakened immune systems. Typically, the effectiveness of Shingrix in preventing shingles is 68–91%, depending on how the condition affects the immune system.

While shingles is not dangerous for many people, in very rare cases it can cause pneumonia, inflammation of the brain, and death. The infection may also lead to long-term pain. If shingles occurs on the face close to the eye, it may lead to vision loss.

Factors that increase the likelihood of developing shingles include older age and a weakened immune system.

Treatment includes antiviral medications and pain medications.

Getting the shingles vaccine can significantly lower the risk of developing shingles. People may be able to prevent complications such as PHN by covering the rash to avoid spreading the virus to others, among other measures.