5 Things to Know About Chicken Pox

Chicken pox is a ubiquitous part of childhood. It has crossed many centuries, cultures and continents, affecting up to 95 percent of the population. Sometimes known by its formal name, varicella zoster virus, chicken pox is a highly contagious viral infection.

Once the varicella zoster virus enters the body, it reproduces rapidly. The rash it causes only occurs after its second round of reproduction. It's believed that the virus can be at work in the body for up to 21 days before the telltale blisters show up. This prolonged incubation period is what makes chicken pox such a contagious condition. In fact, if you haven't had chicken pox and you live with someone who has developed it, it's almost impossible not to catch it yourself.


Chicken pox becomes pretty obvious once it starts producing symptoms. It's primarily distinguished by the itchy blisters it causes, which can range in number from 30 to 1,500. Chicken pox blisters generally show up first on the scalp, face and abdomen, and then spread to limbs.

The virus also produces a fever. In children, the fever can show up after the rash; in adults, it's likely to happen first. Eventually, after a week or so, the fever subsides and the chicken pox blisters scab and dry out.

Now that you know the basics of chicken pox, you should learn some other important facts about the virus. On the following pages, we'll cover five things you need to know about chicken pox.

Chicken pox is generally considered a children's illness. In fact, adolescents and adults make up only 5 percent of varicella zoster virus cases. That's because, due to the highly contagious nature of the virus, very few people make into adulthood without having been exposed to it. But, occasionally, that happens. And contracting chicken pox at an older age can increase your odds of having a more severe infection. Consider this: Even though people who get chicken pox in adulthood are a small percentage of the overall number of infections, they make up around 35 percent of chicken pox-related deaths.

Other risk factors for contracting a severe case of chicken pox include:

  • Being pregnant.
  • Having a condition, like cancer, that leads to a weakened immune system.
  • Taking steroids, such as those prescribed for asthma.
  • Being under 1 year of age.

Infants, in particular, are at risk for severe complications. Not only are they too young to have been inoculated against it, they also haven't developed the necessary antibodies for fighting off the virus.

The parents of infants, and anyone in the risk categories listed above, should be on the lookout for signs that the virus has worsened. On the next page, we'll further explore the symptoms associated with severe forms of chicken pox. Keep reading to find out more.

Most of the time, chicken pox is a harmless infection. But, as we mentioned on the previous page, it can become more serious. Signs that your chicken pox has become severe include:

  • A fever over 102 degrees Fahrenheit (39 degrees Celsius)
  • A fever lasting longer than four days
  • Rash spreading to your eyeballs
  • An infected rash
  • Dizziness
  • Tremors
  • Stiff neck
  • Vomiting
  • Coughing

It's also important to note that even though children aren't as likely as adults to develop a severe case of chicken pox, they can be at risk for an infected rash. This usually happens during scratching when bacteria from fingernails makes its way into open blisters. So, in addition to discouraging your child from scratching the chicken pox rash, you might also want to make sure his or her fingernails are trimmed and cleaned.

On the next page, you'll learn another important fact about chicken pox.

As we have mentioned, scratching a chicken pox rash is something that should be avoided when at all possible. Not only can it increase the odds of a secondary infection, it can also lead to permanent scarring.

There are ways to reduce itchiness so that scratching is less likely. One of the most frequently recommended therapies is an oatmeal bath. Oatmeal is an ideal treatment because it has several positive effects on skin, including moisturizing, anti-inflammatory and cleansing capabilities.

The oatmeal used for such skin treatments isn't the kind you eat; rather, it's a finely ground powder. You can likely find an oatmeal bath at your local drugstore, but if you aren't able to leave the house, make your own by grinding uncooked oatmeal in a blender and adding two cups of it to a warm bath.

In addition to oatmeal, you might also want to use calamine lotion to reduce itching and gloves to cut back on scratching.

When it comes to treating fever, over-the-counter pain relievers usually do the trick. However, be aware that aspirin taken during a bout of chicken pox can lead to Reye syndrome. Children are at particular risk for this complication.

You might be able to avoid all of these symptoms if you follow the advice on the next page.

After 1995, chicken pox started becoming less widespread -- at least in the United States. That's the year the U.S. Food and Drug Administration approved Varivax, a vaccine for chicken pox. Since then, the number of cases of varicella zoster virus have dropped by nearly 88 percent.

Varivax isn't completely foolproof. A type of the virus known as breakthrough chicken pox can still occur after one dose of the vaccine. Because of this, a booster shot of the Varivax is recommend. After that, only about one in 10 people will get breakthrough chicken pox. Fortunately, this is a milder version of the infection; it tends to produce a smaller rash and fewer complications.

People who have already had chicken pox have built up an immunity to the virus and don't need a vaccine. Pregnant women; babies under a year old; cancer, leukemia and HIV patients; and people on steroids are other groups who shouldn't get a shot. For these people there is a product called varicella zoster immune globulin (VZIG) that, while not a vaccine, can protect someone exposed to the virus for up to 96 hours.

One more important fact coming up on the next page.

Once you've had chicken pox, you can never get it again. What you can come down with later, however, is shingles. After chicken pox, the varicella zoster virus remains latent in nerve cells. Down the road, it can reactivate in the form of herpes zoster virus, or shingles.

Not everyone who had chicken pox will get shingles, but those who do have usually experienced a risk factor of stress, certain illnesses and medications, or advanced age. It's believed that about half of the unvaccinated people who live to be 85 years old will experience shingles.

The symptoms of shingles are different from chicken pox, and tend to be more excruciating and prolonged. They include:

  • Intense pain
  • Itching
  • Tingling sensations
  • Fever
  • Chills
  • Nausea

The pain caused by shingles can linger for years after the rash and other symptoms have subsided. When this happens, it's known as post herpetic neuralgia. Fortunately, there are medications designed to treat shingles, as well as a vaccine for people over age 60.

On the next page we have lots more information about chicken pox, shingles and other infectious diseases.

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  • Ackerknecht, Edwin. "A Short History of Medicine." JHU Press. 1982. (Feb. 7, 2008),M1
  • Aetna InteliHealth. "Calamine." (Feb. 7, 2008)'
  • American Social Health Association. "Learn about Herpes." (Feb. 7, 2008)
  • Centers for Disease Control and Prevention. "Childcare and School Immunization Requirements 2005 - 2006." (Feb. 7, 2008)
  • Centers for Disease Control and Prevention. "Varicella (Chicken pox) Vaccination." (Feb. 7, 2008)
  • Centers for Disease Control and Prevention. "Varicella (Chickenpox) Vaccine Q&A." June 22, 2007. (Feb. 9, 2008)
  • Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases. "Varicella." Atkinson W., Hamborsky J., McIntyre L., Wolfe S., eds. 10th ed. Washington DC: Public Health Foundation, 2007.(Feb. 7, 2008)
  • Mayo Clinic. "Chickenpox." March 16, 2007. (Feb. 7, 2008) pox/DS00053
  • Mayo Clinic. "Post Herpetic Neuralgia." June 5, 2006. (Feb. 7, 2008)
  • Mayo Clinic. "Shingles." Nov. 5, 2007. (Feb. 11, 2008)
  • National Institute for Neurological Disorders and Stroke. "Shingles: Hope through Research." Jan. 10, 2008. (Feb. 7, 2008)
  • National Network for Immunization Information. "Exposure Parties." April 26, 2007. (Feb. 7, 2008)
  • Nemours Foundation. "Reye Syndrome." July 2004. (Feb. 7, 2008)
  • Nemours Foundation. "What Makes Chickenpox Itch?" March 2007 (Feb. 7, 2008)
  • Public Health Agency of Canada. "Chickenpox." Dec. 11, 2003. (Feb. 7, 2008)
  • Rauch, Daniel. "Chickenpox." MedlinePlus Encyclopedia. July 26, 2007. (Feb. 7, 2008)