What Triggers a Shingles Outbreak?

Medically Reviewed on 3/2/2022

What is shingles?

Shingles is a viral infection that causes painful rashes on the body. Shingles is triggered by a weakened or compromised immune system.
Shingles is a viral infection that causes painful rashes on the body. Shingles is triggered by a weakened or compromised immune system.

Shingles, also known as herpes zoster, is a virus infection that causes painful rashes on the body, usually on one side of your torso. It is caused by the varicella-zoster virus (VZV), the same virus that causes chickenpox.

After you’ve had chickenpox as a child, the virus lays dormant in your body. A strong immune system usually keeps the VZV in check. It’s when your immune system becomes compromised or is weakened, however, that triggers the VZV to reactivate and cause shingles.  

While shingles are not contagious, it can spread the VZV to someone who hasn’t had it yet and give them chickenpox. If you’ve never had chickenpox, avoid those who have shingles and, conversely, if you have shingles, don’t go near anyone who hasn’t had chickenpox or has a weak immune system.

Symptoms of shingles

People often experience itching, tingling, and even pain in the area where shingles will develop before there is a visible rash. These can be felt up to several days prior to the rash appearing.  

Most commonly, the rash occurs in a single stripe around the waistline on one side of the body or the other. Sometimes the rash appears on the side of the face. Face shingles can affect the eyes and impair vision. People who already have weakened immune systems can develop more widespread rashes across the body that resemble a chickenpox rash.  

Other symptoms of shingles can include:

For the most part, shingles symptoms tend to be mild with slight itching and discomfort. Though more severe cases are rare, they do happen, and the pain can be debilitating. 

Most cases of shingles will last between three and five weeks, and follow a general pattern: 

  • The first sign is a burning or tingling sensation on the skin and can include numbness or itching
  • Within a couple of days, a red rash will appear in the affected area 
  • A few days after the rash appears, it will turn into fluid-filled blisters
  • About seven to ten days after that, the blisters dry up and crust over
  • A couple of weeks later, the scabs fade away

While most people get shingles only one time in their life, it is possible to have it more than once.


Causes of shingles

Shingles are caused by the varicella-zoster virus (VZV), the same virus that causes chickenpox. Anyone who’s had chickenpox is susceptible to developing shingles. The Centers for Disease Control and Prevention estimate that 1 out of 3 people will develop shingles at least once in their lifetime.    

The risk of getting shingles increases as a person gets older. Scientists believe this may be because a person’s immunity naturally declines as they age. A weakened or compromised immune system is the main trigger for reactivating the virus in the body, causing the outbreak of shingles.

Diagnosing shingles

A doctor can usually diagnose shingles with a simple physical exam and questions about your symptoms. If the diagnosis isn’t clear, or if the person is in a high-risk category, like people with an already-weak immune system or pregnant women, the doctor will perform a shingles test. This involves taking a sample from the rash and checking it for the VZV.

Treatments for shingles

There are several antiviral medications available to treat shingles and shorten its length and severity. These include acyclovir, valacyclovir, and famciclovir. It is recommended that you see a doctor and get a prescription for one of these drugs as soon as possible after developing symptoms or when the shingles rash appears.    

Over-the-counter anti-inflammatory medication is usually recommended to help relieve pain caused by shingles. Prescription-strength opioid pain medication might be prescribed if the pain is moderate or severe. Consult with your doctor for the best pain medication treatment for you.

Shingles vaccination  

Recombinant zoster vaccine, also known as RZV Shingrix, is recommended to prevent shingles in adults 50 and older. Zostavax used to be recommended and available in the United States, but as of November 2020, it is no longer available.  


Shingles is a painful rash caused by the same virus that causes chickenpox. See Answer

What's the difference between chickenpox and shingles?

Chickenpox and shingles are two infectious diseases that are often confused with one another. That’s because they’re caused by the same virus, called varicella-zoster.

Varicella is a highly contagious virus that spreads through coughing and sneezing, or through direct contact with an infected skin lesion. It commonly spreads in schools, due to the high volume of students potentially in close contact. Adults can get infected with varicella, too, and these cases tend to be more serious than in those of healthy children.

Vaccinating against chickenpox is very common in the U.S. There’s also a vaccine available for shingles for people who are 50 and older.

Symptoms of chickenpox and shingles

Although both diseases are caused by the same virus, you can tell them apart relatively easily.

Symptoms of chickenpox

Chickenpox is preventable with a vaccine. About 98% of people who have been immunized don’t develop it. The 2% who will contract chickenpox usually experience mild cases. The illness lasts for one week on average.

Signs and symptoms of chickenpox include:

  • Sudden onset of fever
  • Loss of appetite
  • Body aches and chills
  • Red, itchy rash on the body (may develop on eyes, inside the mouth, and genital area)
  • Fluid-filled blisters that break and scab

You start to feel the symptoms of chickenpox 10 to 21 days after exposure. This can make it hard to pinpoint exactly when you or your child might have contracted it.

Although this disease normally affects children, adults can get it too. Adults usually get more severe cases than children do. People who are pregnant or have weakened immune systems are more likely to develop side effects.

There can be serious side effects of chickenpox. They include:

  • Dehydration
  • Bacterial infection of cuts and breaks in the skin lesions
  • Pneumonia
  • Inflammation or infection of the brain
  • Possible fetal defects in pregnant women
  • Death

Symptoms of shingles

Shingles — also known as herpes zoster — has distinctive symptoms, such as nerve pain. This pain can last for weeks or even months after the other symptoms have cleared (post-herpetic neuralgia).

Symptoms of shingles include:

  • Headache
  • Fever
  • Muscle aches and chills
  • Tingling or itchy skin
  • Painful, blister-like rash on the torso, face, eyes, or genitals
  • Rash typically appears on one side of the body

Recovery time varies. On average, the rash clears within 7 to 10 days and nerve pain lessens or disappears within 2 to 4 weeks.

The risk for complications increases with the age of the patient. Long-term nerve pain is the most common complication of shingles. It can last for months or even years after the rash has disappeared. It’s described as a burning, shooting, stabbing pain.

Other complications of shingles are:

Causes of chickenpox and shingles

Both diseases are originally spread from person to person. The key difference is that shingles happen when the varicella virus reactivates years after recovery from chickenpox.

Causes of chickenpox

Chickenpox is caused by the virus varicella-zoster. You can become infected through contact with someone who has chickenpox or shingles. It spreads through droplets, like when coughing or sneezing. It can also spread if you touch a ‘pock,’ or skin lesion.

When you get chickenpox, you’re contagious from 1 to 2 days before the rash develops until after all the blisters have scabbed.

Causes of shingles

You cannot get shingles from someone who has shingles. If you’ve never been vaccinated for chickenpox, then it’s possible to get chickenpox from someone with shingles.

Unlike chickenpox, you can’t spread the virus through droplets. You can only spread shingles through direct contact with the blisters or rash. It’s unlikely you’ll spread the virus if you keep the rash covered. After the blisters develop a crust, you’re no longer contagious.

Stages of chickenpox and shingles

The progress of each disease can be marked through stages. Some stages will last longer for some, depending on your age, immune system, and other factors.

Stages of chickenpox

The main stages in chickenpox are:

  1. Exposure to the virus: It takes 10 to 21 days after exposure for symptoms to start.
  2. Initial symptoms: Feeling unwell, body aches, fever, and headache are usually the first symptoms to set in.
  3. Small red bumps on the body: These usually develop on the torso or face first, eventually covering the body.
  4. Bumps develop into blisters: The itchy lesions will fill with fluid and become blisters.
  5. Blisters scab over and heal: After all your blisters scab over, you’re no longer contagious.

Stages of shingles

  1. Feeling unwell: You might develop fever, headaches, or body aches before developing the rash.
  2. Tingling pain: It’s common to feel tingles, pain, or itchiness in the area the rash will develop.
  3. Burning rash: Anywhere from 1 to 5 days after the tingling started, the rash will start to develop.
  4. Blisters: The rash will start to blister and then crust over.

You may still feel mild or extreme pain after the rash is gone, due to a condition called post-herpetic neuralgia (PHN). You can develop shingles more than once, but it is rare.

Diagnosing chickenpox and shingles

The doctor will usually be able to diagnose chickenpox or shingles by inspecting the rash and marks, noting your signs and symptoms, and asking you about your vaccination history. They can also do several tests to confirm that you have the varicella virus, such as:

  • Blood test: A needle is inserted into a vein and a vial of blood is removed. The blood is then tested for the varicella virus or its antibodies.
  • Blister test: A fluid sample is taken from a blister with a cotton swab. It’s then tested for varicella or antibody properties.

If you think you or your child could have chickenpox, contact your doctor. Since chickenpox is highly contagious, the doctor’s office may have procedures that safeguard against infection. It’s best to call first and inform them about your reason for visiting.

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Treatments for chickenpox and shingles

There are vaccines available for both shingles and chickenpox. Today, they’re widely used in the U.S. and around the world.

Shingrix is a vaccination for shingles that’s recommended for healthy adults over the age of 50.  Varicella is the vaccine used for chickenpox. It’s usually administered to children between the ages of 12 and 15 months, and then again between 4 and 6 years old.

A cool bath infused with baking soda, oatmeal, or colloidal oatmeal may help soothe the skin lesions caused by chickenpox and shingles. Applying calamine lotion can also help calm the skin and reduce itchiness.

Resist scratching your skin while you have chickenpox or shingles, because it can leave the wounds open to infection and cause scars on your skin.

Aspirin is not recommended for pain relief when you have chickenpox. Its use has been associated with Reye’s syndrome in children who have chickenpox. Reye’s syndrome is a serious disease that affects the brain and liver.

If you have shingles, your doctor may prescribe an antiviral medicine to ease symptoms and speed healing. These medicines are most effective when taken as soon as the rash develops:

  • Famciclovir
  • Acyclovir
  • Valacyclovir

Consult your doctor before taking medication.

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Medically Reviewed on 3/2/2022

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Centers for Disease Control and Prevention: "Shingles (Herpes Zoster)."

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National Center for Immunization and Respiratory Diseases: "Prevention of Herpes Zoster: Recommendations of the Advisory Committee on Immunization Practices (ACIP)."

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National Foundation for Infectious Diseases: "Chickenpox (Varicella)."

National Foundation for Infectious Diseases: "Shingles (Herpes Zoster)."

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