What is Chickenpox?

What is Chickenpox?

Chickenpox is a highly contagious infection characterized by a fever and rash caused by a virus. The varicella-zoster virus causes uncomfortable symptoms that take most people 1 to 2 weeks to recover. After one to two days of flu-like symptoms, a blister-like rash appears on the face and trunk of the body before spreading to the outer areas.

Chickenpox was once a common childhood illness in the United States but has become much rarer due to the varicella vaccine. Because it occurs so seldom, chickenpox can be misdiagnosed by pediatricians.

Smallpox vs. chickenpox

Smallpox and chickenpox are caused by different viruses (unlike chickenpox, smallpox is caused by the Variola virus). Although both infections will cause a rash, these two conditions are quite different.

Smallpox spots are smaller than the blisters caused by chickenpox and contain a smaller amount of fluid. While chickenpox blisters appear at different times on different areas of the body, smallpox sores appear all over the body simultaneously.

Doctors can easily determine the difference between these two conditions but rarely have to make this distinction as smallpox has not been detected in the United States for many years. 

Shingles vs. chickenpox

After a person recovers from chickenpox, the virus that caused the illness remains in their system and becomes inactive or dormant. This means certain situations or conditions could reactivate the virus later in life, making the person sick again. This second stage of chickenpox is called shingles. To have shingles, a person must have had chickenpox earlier in life, usually in childhood.

Shingles cannot be passed to other people in the form of shingles. Other people can, however, become infected with chickenpox after exposure to someone with shingles if they have not already had chickenpox or received the chickenpox vaccine. This can mean that adults with shingles who care for children who have not had varicella vaccinations may increase the children’s risk of contracting chickenpox.

Although caused by the same virus, shingles and chickenpox result in very different experiences for those infected. Shingles affect the nerves of the body and usually cause a small but very painful rash on one side of the torso or flank (upper abdomen or back and sides), the face, or the neck. This itchy skin rash may occur on the face, trunk, or other area. Like chickenpox blisters, a shingles rash will turn into blisters filled with fluid that will break and scab over within several days. Unlike chickenpox, this rash may cause itching, tingling, and pain lasting for three or more months after the blisters have gone.

Stages of Chickenpox


There are several distinct stages of progression commonly associated with a chickenpox infection:

  • One or two days of flu-like symptoms, including fever, headache, fatigue, and stomach issues/lack of appetite.
  • An itchy rash that develops on the face and body. The severity of this rash can vary. At times the rash can extend to the eyelids, the genitals, and inside the mouth.
  • The rash develops into fluid-filled blisters wh,ich may take 3 to 5 days to crust over. Since the blisters do not all erupt on the body simultaneously, some will begin to heal sooner than others.
  • Scabs that form in place of the blisters will begin to fall off in about a week.

Signs & Symptoms of Chickenpox


Anyone who has not had chickenpox or received the chickenpox vaccine can come down with this very contagious disease if exposed to it. Signs and symptoms of chickenpox may be challenging to pinpoint before the telltale chickenpox rash develops because it may at first appear to be cold- or flu-like.

Before the rash appears, there may be a combination of any of the following chickenpox symptoms:

  • Tiredness, or a general feeling of malaise
  • Fever (usually less than 102F) that can last 3 to 5 days
  • Cough or runny nose (cold-like symptoms)
  • Headache
  • Loss of appetite
  • Joint or muscle aches

The classic chickenpox rash follows these symptoms, which turns into itchy, fluid-filled blisters that will scab over and fall off in about a week.

Chickenpox is generally considered a childhood disease, but adults who have never had the virus or the vaccine are still at risk. Adult symptoms are typically similar to those experienced by children but may at times, become more severe. The progression of symptoms is the same for adults and children as the virus moves through its stages.

A primary care physician can help in the diganosis and treatment of chickenpox in both adults and children.

What Causes Chickenpox?


The varicella-zoster virus causes chickenpox. The varicella virus is highly contagious and is transmitted easily. Things to keep in mind include:

  • A contagious virus causes chickenpox.
  • Most cases of chickenpox result from exposure to an infected person.
  • The virus is contagious for a day or two before blisters appear on the skin.
  • The virus remains contagious until all blisters have scabbed over.
  • Coughing or sneezing can spread the chickenpox virus.
  • The virus can spread through contact with saliva or fluid from blisters.

How to Prevent Chickenpox


The chickenpox vaccine is given in two doses and prevents chickenpox in over 90% of the people who receive it. The first dose should be given to children between the ages of 12 and 15 months. The second dose is given as a booster between 4 and 6 years of age.

The vaccine may also be given to older children and adults who have not received it, with the two doses being given about one month apart. Getting the chickenpox vaccine is an important option for older adults for whom a chickenpox infection can be quite severe.

Chickenpox Complications


Complications resulting from a chickenpox infection are rare but not unheard of. People who have not been vaccinated may develop severe symptoms. This risk increases with age. Additionally, subgroups of people are more likely to develop complications, including pregnant women, newborn babies, infants up to four weeks old, transplant patients, and others with weakened immune systems.

Complications may include:

  • Infection of the skin in and around blisters.
  • Breathing problems which may include the development of pneumonia, especially in pregnant women.
  • Encephalitis is an inflammation of the brain.
  • Reye’s syndrome swelling of the liver and brain.
  • Bleeding caused by a ruptured blood vessel.
  • Sepsis which is a potentially life-threatening infection of the blood.
  • Congenital varicella syndrome can develop when chickenpox infections occur during the first 20 weeks of pregnancy.
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Trust NewYork-Presbyterian for Chickenpox Care

Should you suspect that you or someone you care for has chickenpox your first call should be to schedule an appointment or video visit with NewYork-Presbyterian or at a medical group location. NewYork-Presbyterian offers you the highest level of care with same-day appointments for critical needs and ease of scheduling with early, late, and weekend hours.

At NewYork-Presbyterian most insurance is accepted, referrals to NewYork-Presbyterian specialists are easily available, and the patient portal keeps all your important healthcare information in one place while keeping you informed. You’ll learn about all the treatment options available to you and be guided in making the best decisions for your care.