What is chickenpox?
Chickenpox is a very contagious disease caused by the varicella virus. Chickenpox is also called varicella.
How does it occur?
The chickenpox virus is spread through the air by infected people when they sneeze or cough. The disease also spreads from touching the chickenpox blisters without careful handwashing afterwards.
If you have already had chickenpox, you are probably immune. Being immune means that if you are exposed to chickenpox again, your body can fight off the infection and you will not get sick. If you had a very mild case of chickenpox with just a few blisters, it is possible to have chickenpox again, but this is rare.
After infection, the virus stays in your body for life. The virus can later cause shingles, which causes a painful, blistering rash on one side of the body. Someone who has not had chickenpox or the chickenpox shot could get chickenpox from close contact with someone who has shingles.
Less than 5% of adults are at risk of having chickenpox. Most are immune because they have had chickenpox or the shot. However, when an adult has chickenpox, the infection can be more serious than it is in children.
What are the symptoms?
Symptoms usually appear 10 to 21 days after exposure to the virus. The symptoms include:
- a red, itchy, rash of blisters that usually appears first on the face, scalp, or trunk and can spread to the rest of the body and start to itch
- aches and pains
- mild headache
- feeling irritable.
How is it diagnosed?
Your healthcare provider will ask about your symptoms and examine you. If you are pregnant and think you have been recently exposed to chickenpox, you may have a blood test to see if you are immune. Chickenpox during pregnancy can cause birth defects or even cause the baby to be stillborn. If a mother has the infection at the time of delivery, it can spread to the baby during birth.
How is it treated?
If you have been exposed to chickenpox or you think you have chickenpox, see your provider as soon as you can. Your healthcare provider may prescribe an antiviral medicine, such as acyclovir. The medicine helps only if you start taking it within 24 hours after the first sores appear. According to recent research, antiviral medicine has mild benefits: it reduces the number of sores and lessens the time you are sick. It does not prevent other problems caused by chickenpox.
Pregnant women who have recently been in close contact with someone who has chickenpox and are not immune may be given a shot of Varicella-zoster immune globulin (VZIG). When given within 72 hours after exposure, VZIG helps prevent chickenpox or lessens its severity. The shot is safe for mother and baby.
For treatment of your symptoms, follow the guidelines provided below under the heading "How can I take care of myself?"
How long do the effects last?
Chickenpox is contagious 1 to 2 days before the rash appears. It continues to be contagious until all of the blisters have crusted over, which usually takes 4 to 7 days.
If there are no complications, adults have the chickenpox infection for 3 to 7 days. Children are most commonly ill for about 5 to 10 days. They usually miss 5 or 6 days of school or childcare due to chickenpox.
Adolescents or adults are more likely to have complications from chickenpox than children. People who have trouble fighting infections are especially at risk for problems. This includes people being treated for cancer with chemotherapy or radiation, people who use steroids for other medical conditions, and people who have HIV infection. Possible complications are pneumonia or problems with the kidneys, heart, or joints. The nervous system may be affected, which may cause irritation and swelling in the brain (meningitis or encephalitis) or other types of nervous system problems. Sometimes an infection of the skin develops because bacteria get into sores when they are scratched.
How can I take care of myself?
- Take a lukewarm bath every 3 to 4 hours for the first few days. Add 2 ounces (4 tablespoons) of baking soda, cornstarch, or oatmeal (dry, uncooked oats) to a tub of water. Use soap in one of the baths each day to clean as much bacteria off the skin as possible. Pat your skin dry. Do not rub it when drying.
- You can try using calamine lotion on the chickenpox sores to help relieve itching, but do not put it on your face.
- Put a towel-covered ice pack or cool moist washcloth on itchy areas for 20 to 30 minutes. (Do not share the towel or washcloth with anyone else.)
- If the itching is severe or making it hard to sleep, take a nonprescription antihistamine, such as Benadryl (diphenhydramine) capsules.
- Trim your fingernails and wash your hands often with soap and warm water to help keep the rash from becoming infected if you scratch it.
- If you have blisters in your mouth, eat foods that are cool, soft, and bland. Avoid any foods that are acidic or salty.
- Take a nonprescription pain reliever such as acetaminophen for headache, fever, or general aches and pains. Do not give ibuprofen to children with chickenpox. Ibuprofen use while a child has chickenpox may cause a severe skin infection. Also do not give any medicine that contains aspirin or salicylates to a child or teen. This includes medicines like baby aspirin, some cold medicines, and Pepto Bismol. Children and teens who take aspirin are at risk for a serious illness called Reye's syndrome.
- Call 911 for emergency care if:
- You become confused, disoriented, or extremely sleepy or have trouble waking up.
- You have a severe headache or a stiff neck.
- You have trouble standing up or walking.
- You have a rash involving 1 or both eyes or you are very sensitive to bright light.
- Call your healthcare provider right away if:
- You have trouble breathing or a severe cough.
- You are an adult and have a fever higher than 101.5° F (38.6 C).
- A child has a fever of 103° F (39.4° C) or higher orally (add one degree if you take the temperature in your child's bottom).
- The blisters appear infected:
- Area around blister is red.
- A red streak is leading from the blister toward the heart.
- Pus (usually yellow) starts leaking from the blisters.
What can be done to prevent chickenpox?
A vaccine is available to protect against chickenpox. Two shots are recommended for people 13 years or older who have not had chickenpox and who have not been previously vaccinated. The chickenpox vaccine is about 70 to 85% effective in preventing a mild infection and 95% effective in preventing moderate to severe infection.
If you have not had chickenpox or the chickenpox shot and you are exposed to chickenpox, your healthcare provider may give you a shot of Varicella-zoster immune globulin (VZIG) to help prevent the infection. You may also be given this shot if you have trouble fighting infections; for example, if you have cancer, HIV, or AIDS, or if you are receiving medicines that weaken the immune system.
Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.
HIA File infd4545.htm Release 13/2010