Almost everyone is familiar with chickenpox -- before the introduction of the chickenpox vaccine, 90 percent of U.S. children had the disease by age 10 [source: Penn State]. You may recall the red bumps your mom told you not to pick, the calamine lotion that gave you little relief from the itching, and the inevitable scar left behind by that blister you just couldn't leave alone. And if you've had chickenpox, then the virus that caused that week of discomfort is still with you. It remains in your body to this day, and it's the same virus that causes shingles.
Chickenpox and shingles aren't the same disease, but the same virus causes them: Varicella zoster [source: Mayo Clinic]. While it's rare for an adult to get chickenpox, both children and adults can get shingles -- but only if they've already had chickenpox. The varicella zoster virus that lives in your nervous system after you've had chickenpox can reactivate under certain circumstances, such as emotional stress, cancer or immune deficiency, and this causes shingles.
Because you can't get shingles unless you've already had chickenpox, the disease itself isn't contagious; however, the varicella zoster virus is. This means someone with shingles can give someone else chickenpox if that person hasn't had the disease. But this can only occur if the person comes in contact with a broken shingles blister. Chickenpox, on the other hand, is extremely contagious and can be passed through contact with blisters or through the air [source: WebMD].
Chickenpox initially causes flu-like symptoms, including a fever, cough and sore throat. Then come the blisters -- hundreds of them spread over the entire body. They last about a week and heal naturally. Shingles symptoms are similar, but the blisters aren't spread evenly over the entire body. These blisters move along nerves and usually erupt in a band on one side of the body, which is called a dermatome. There are some serious side effects associated with shingles, including organ damage and post-herpetic neuralgia, a painful condition that affects your nerves and skin [source: National Foundation for Infectious Diseases].
There aren't antibiotics to cure chickenpox or shingles; however, you can get vaccinated for both diseases. While chickenpox isn't a serious condition in healthy children, shingles can have critical long-term consequences [source: WebMD]. Without vaccination, about 20 percent of people who have had chickenpox will eventually get shingles [source: Skudlarska]. Keep reading for more information on chickenpox and shingles.