Shingles (herpes zoster)

Key facts

• Shingles is a painful rash caused by the reactivation of the varicella-zoster virus (VZV), the same virus that causes chickenpox.
• Anyone who has had chickenpox can develop shingles, although it is more common in adults over 50 years of age.
• The main symptom is a rash that appears on one side of the body, often as a single stripe of blisters.
• Shingles is not contagious, but the virus can be spread to someone who has never had chickenpox. This will cause chickenpox, not shingles.
• A safe and effective vaccine is available to prevent shingles and its complications.
• Antiviral medications can reduce the severity and duration of shingles, especially if started early.

Overview

Shingles, also known as herpes zoster, is a viral infection that causes a painful rash. It is caused by the varicella-zoster virus (VZV), the same virus that causes chickenpox. After a person recovers from chickenpox, the virus remains inactive in the body. Shingles occurs when the virus reactivates later in life, often when the immune system is weakened. The rash typically appears on one side of the body, often as a single stripe of blisters. The symptoms of shingles can include pain, itching, tingling and numbness, as well as fever, headache, chills and fatigue. Shingles is not contagious, but the virus can be spread to someone who has never had chickenpox, causing chickenpox. A safe and effective vaccine is available to prevent shingles and its complications. Treatment with antiviral medications can reduce the severity and duration of shingles, especially if started early. Complications can be severe, especially for those who are immunocompromised.

Risk factors

Anyone who has had chickenpox can develop shingles. However, it’s much more common in adults over the age of 50. The risk increases with age because the immune system tends to weaken, making it harder to keep the VZV suppressed.

Other factors that can increase the risk of shingles include:

• Weakened immune system. Conditions like HIV and AIDS, cancer, and organ transplantation, as well as medications that suppress the immune system, can increase the risk.
• Stress. Periods of high stress may temporarily weaken the immune system, potentially triggering a shingles outbreak.
• Certain medical conditions. Conditions like diabetes, chronic kidney disease and lung disease may increase the risk.

Symptoms

The most common symptom of shingles is a painful rash. They include the following.

• Pain, itching, tingling, or numbness usually occurs before the rash appears. This can happen days or even weeks before the rash.
• A rash typically appears on one side of the body, often as a single stripe or band of blisters. It can also appear on the face, sometimes near the eye. If it occurs near the eye, it is a medical emergency. Contact your health-care provider right away.
• The rash consists of small, fluid-filled blisters that break open and crust over within a few days.
• Some people may experience fever, headache, chills and fatigue.

The pain associated with shingles can be intense and is often described as burning, throbbing or stabbing.

Transmission

Shingles itself is not contagious, so you can’t get shingles from someone who has it.

However, you can spread the varicella-zoster virus (VZV) to someone who has never had chickenpox or the chickenpox vaccine. In that case, they would develop chickenpox, not shingles.

The virus spreads through direct contact with the fluid from the shingles blisters. Once the blisters crust over, the risk of spreading the virus is very low.

To prevent spreading the virus:

• keep the rash covered
• avoid touching the rash
• wash your hands frequently.

It’s especially important to avoid contact with:

• pregnant women who have never had chickenpox or the vaccine
• newborns
• people with weakened immune systems.

Diagnosis

Shingles can usually be diagnosed based on the characteristic appearance of the rash and your medical history. The unique pattern – a stripe of blisters on one side of the body – is often a clear indicator.

If the diagnosis is uncertain, especially if the rash is atypical or if there are complications, a sample from a blister can be sent to a lab for testing. This test can confirm the presence of the varicella-zoster virus (VZV).

Treatment

The primary treatment for shingles involves antiviral medications, such as acyclovir, valacyclovir, or famciclovir. These medications can help:

• reduce the severity and duration of the illness
• reduce the risk of complications.

Antiviral medications are most effective if started within 72 hours of the rash appearing.

Other treatments include:

• Pain relievers. Over-the-counter pain relievers like ibuprofen or acetaminophen (paracetamol) can help manage the pain. In some cases, stronger pain medications, such as opioids or nerve pain medications, may be prescribed.
• Calamine lotion or cool compresses. These can help soothe the skin and relieve itching.
• Keeping the rash clean and dry. This helps prevent secondary bacterial infections.

Complications

The most common complication of shingles is postherpetic neuralgia (PHN), which is persistent nerve pain that can last for months or even years after the rash has healed. This pain can be severe and debilitating.

Other complications can include:

• bacterial infections of the blisters
• scarring
• eye problems or vision loss (if the rash involves the eye area)
• in rare cases, pneumonia, encephalitis (inflammation of the brain), or stroke.

People with weakened immune systems are at higher risk for these severe complications.

Prevention

Herpes zoster vaccine is available in some countries. The vaccine is highly effective and licensed for adults age 50 years and older, even if they’ve had shingles before.

Being vaccinated significantly reduces the risk of developing shingles and PHN.

Chickenpox vaccine and shingles

The chickenpox vaccine (varicella vaccine) can reduce the risk of developing shingles later in life.

The chickenpox vaccine contains a weakened version of the varicella-zoster virus (VZV). Studies have shown that children who received the chickenpox vaccine are significantly less likely to develop shingles compared to those who contracted chickenpox naturally.

WHO response

The World Health Organization’s Immunization, Vaccines and Biologicals department is responsible for targeting vaccine-preventable diseases, guiding immunization research and establishing immunization policy.

WHO will issue updated recommendations on the use of chickenpox and shingles vaccine in March 2025.

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