Chickenpox (Varicella): Symptoms, Causes, Prevention

Medically Reviewed by Poonam Sachdev on November 14, 2023
7 min read

Chickenpox is a very contagious infection caused by the varicella-zoster virus. It mainly affects kids, but adults can also get it. The telltale sign of chickenpox is a super-itchy skin rash with blisters. Over the course of several days, the blisters pop and start to leak. Then they crust and scab over before finally healing.

Chickenpox is generally mild, especially in children. 

Chickenpox is caused by the varicella-zoster virus and spreads easily and quickly from someone who is infected.


Children under age 2 are most at risk for chickenpox. In fact, 90% of all cases occur in young children. But older children and adults can get it too.


If someone has the virus and you touch their rash or fluid from their blisters, you can get chickenpox. The virus can also spread to you if someone with chickenpox coughs or sneezes and you breathe in droplets. When you have chickenpox, you are contagious from 1 to 2 days before the rash appears until all your blisters have dried and crusted over. 

Chickenpox incubation period

On average, your symptoms will appear within 10 to 21 days after you have been exposed to the virus. 

The first sign of chickenpox is usually a general feeling of not feeling well.

Early-stage chickenpox

Some other symptoms of chickenpox that can happen a few days before the rash include:

  • Body aches
  • Fever
  • Feeling very tired 
  • Loss of appetite
  • Headache

Chickenpox rash

Within a day or two, you’ll develop the most common symptom of chickenpox, which is an itchy rash. It usually shows up on your face, chest, and back first, but the spots can spread to the rest of your body. In severe cases, they can form in your mouth, eyes, anus, or genitals. It happens in three phases.

During the first phase, you’ll develop itchy, raised bumps. They may be pink or red or the same color as your skin or darker. Doctors call these “papules.” As many as 250 to 500 of them can pop up all over your body. New bumps will appear for several days.

In the next phase, these bumps will turn into small, fluid-filled blisters called “vesicles.” They last about a day before they pop and start to leak. 

Finally, these open wounds crust over and turn into scabs. As they heal, new bumps continue to appear. You could have bumps, blisters, and scabs at the same time. You can spread the virus to other people until all the spots crust over.

How long does chickenpox last?

Chickenpox symptoms usually last about 4-7 days.

Your doctor will likely be able to tell if you have chickenpox by looking at your rash. If there is any doubt, they can do a test. Because chickenpox is highly contagious, call your doctor before going to the office. 

Mpox vs. chickenpox

Mpox (previously known as monkeypox) and chickenpox are caused by two different viruses. With both, you will probably get a fever and you will have fluid-filled blisters, but there are differences between the two infections. 

  • Mpox spots appear all at once while chickenpox spots show up over several days. 

  • Mpox sores are typically larger and deeper than chickenpox.

  • Mpox blisters can be painful, chickenpox blisters are just itchy. 

  • All your mpox spots will blister and then crust over at the same time. With chickenpox, you may have spots, blisters, and crusted sores at the same time. 

  • Mpox lasts longer than chickenpox.

Most cases of chickenpox occur in young children, but adults and older children can get it too. 

When adults get chickenpox, they often have more severe cases and are more likely to have complications. 

You’re more at risk for chickenpox if you:

  • Haven’t had the virus before
  • Haven’t been vaccinated for it
  • Work in a school or child care facility
  • Live with children

Medications can help if you have chickenpox.

Acetaminophen (Tylenol)

If you or your child has a high fever or achiness caused by chickenpox, reach for acetaminophen. It can help relieve pain from sores that develop on your skin or in your mouth, too. It’s safe for most people, including pregnant women. For children over 2 months old, use a product specifically made for them and read the instructions for dosing information. 

If your child has chickenpox, avoid anti-inflammatory painkillers like ibuprofen because they can be associated with a serious bacterial skin infection. Never give aspirin to children under age 16. It can lead to a serious complication called Reye’s syndrome that can affect the liver and brain and sometimes cause death.

Prescription medicine

If you’ve been exposed to someone who has chickenpox but don’t have symptoms yet, your doctor may give you an injection of a treatment called immune globulin. It can help your immune system fight chickenpox. Your doctor may consider this medication if you fall into one of the following groups:

  • Children and adults with weakened immune systems
  • Newborns of mothers with chickenpox shortly before or after delivery
  • Premature babies
  • Babies less than 1 year old
  • Adults without evidence of immunity
  • Pregnant
  • A smoker
  • Living with HIV
  • Having chemotherapy (“chemo”) or taking high doses of steroid medication

Newborn babies under 4 weeks old are also at increased risk for complications from chickenpox.

If you’re at risk for severe chickenpox and already have symptoms, your doctor might prescribe an antiviral medication called acyclovir (Sitavig, Zovirax). It can help make your symptoms less severe if you begin the first dose within 24 hours of developing the rash. 

Don’t scratch

Scratching your rash can put you at risk for a bacterial skin infection. It could also cause scarring. If you accidentally scratch your rash, wash your hands with soap and water so you don’t spread the virus. 

Can you get chickenpox twice?

You can get chickenpox again if you’ve already had it, but it’s not common.


There are things you can do at home to ease your symptoms while your body heals. To try a home remedy that might provide chickenpox relief, you can:

  • Take a lukewarm bath with colloidal oatmeal or baking soda. 
  • Dab calamine lotion on your itchy spots.
  • Take an oral antihistamine to help with itching.
  • Get plenty of rest.

It's also important to:

Keep cool

Heat and sweat make you itch more. Use a cool, wet washcloth on super-itchy areas to calm your skin.

Stay hydrated

Drink lots of fluids to help your body rid itself of the virus faster. It’ll also keep you from getting dehydrated.

Choose water over sugary drinks or sodas, especially if you or your child has chickenpox in the mouth. Sugar-free frozen pops are a good choice, too.

Avoid hard, spicy, or salty foods that can make your mouth sore.

Adults have a higher risk for developing complications from chickenpox than children. Those with weakened immune systems due to cancer, HIV, or another condition are also at risk.

Once you’ve had chickenpox, the varicella-zoster virus stays in your nerve cells for years. It can “wake up” and become active again years later. It can lead to shingles, a condition that  happens when the virus, which stays in your body, turns back on. Shingles causes painful blisters. Fortunately, there’s a vaccine for shingles. The CDC recommends two doses of recombinant zoster vaccine for prevention of shingles and similar complications in adults ages 50 years and older. A version of the vaccine is also recommended for people with weakened immune systems ages 19 years and older.

Other complications from chickenpox include:

  • Dehydration
  • Infections caused by bacteria
  • Toxic shock syndrome
  • Brain swelling (encephalitis) or 
  • Swelling of the brain and liver in children and teens with chicken pox who take aspirin (Reye's syndrome)
  • Pneumonia
  • Death (very rare)

The best way to prevent the spread of the virus is to get the varicella vaccine. Children who’ve never had chickenpox should get two doses of the vaccine -- the first at 12 to 15 months of age, and the second between ages 4 and 6. People over age 13 who’ve never been vaccinated should get two doses of the vaccine at least 28 days apart.

If you are pregnant, have a disease that affects the immune system, have been taking medication that impacts the immune system for 2 weeks or more, have cancer, are receiving radiation or chemotherapy, or recently had a blood transfusion or received other blood products, ask your doctor before getting the vaccine. 

If you are over the age of 50 and have had chickenpox, a high-dose vaccine called Shingrix is available to prevent painful outbreaks of shingles. If you are over 19 years old with a weakened immune system, ask your doctor if you should get the shingles vaccine.

After the vaccine, the best way to prevent chickenpox is to avoid being around people with chickenpox.

Most cases of chickenpox are mild and go away on their own. If you have chickenpox but are otherwise healthy, call your doctor right away if you develop any of the following symptoms:

  • The rash gets close to or spreads to one or both eyes.
  • The rash gets very red, warm, or tender. You could have a bacterial skin infection.
  • Bleeding or bruising around your rash
  • Dizziness
  • Shortness of breath
  • Bad cough
  • Bad stomach pain
  • Vomiting
  • Stiff neck
  • You can’t control your muscles
  • Trouble walking
  • Trouble waking up
  • Confusion
  • Fever lasting more than four days
  • Fever over 102 F
  • Dehydration