By Patricia Henderson, MS, RN, C-FNP
Chickenpox (medical term is varicella) is a highly contagious disease caused by the varicella-zoster virus. It spreads from person to person by direct contact or through the air from an infected persons coughing or sneezing. The person with chickenpox is contagious 1-2 days before the rash appears and until all blisters have formed scabs. It takes 10-21 days after contact with an infected person for someone to develop chickenpox. A person may get chicken more than once, but this is very uncommon. The infection is thought to offer lifelong immunity.
Symptoms of chickenpox include a blister-like rash, itching, tiredness and fever. The rash usually appears on the trunk and face first, but can spread over the entire body causing between 250 to 500 itchy blisters. Most cases of chickenpox occur in persons less than 15 years old. Before the use of the varicella vaccine, the disease had annual cycles, peaking in the spring of each year. Mild cases can be treated with anti-itching skin treatments and antihistamines.
Certain groups of persons are more likely to have serious symptoms with complications. These include adults, infants, adolescents and people with weak immune systems from either illnesses or from medications such as long term steroid use. These complications include secondary bacterial infections of skin, lungs, blood and bone.
Other complications are due to the chickenpox virus itself and can include bleeding, pneumonia, and encephalitis (infection of the brain). Chickenpox can cause death in previously healthy unvaccinated children and adults. It is never possible to predict who will have a mild infection and who will have a serious or even deadly illness. There are effective anti-chickenpox drugs available to treat active cases of the disease for those persons at high risk of complications, but the treatment must be started early in the disease to be most effective.
The good news is that chickenpox can be prevented by vaccination. The vaccine was licensed by the Food and Drug Administration in 1995 and is now widely available in private doctors offices and public health clinics.
Who should be vaccinated?
? All children between 12-18 months with one dose of vaccine.
? Children who have had chickenpox do not need the vaccine.
? Children between 19 months and their 13th birthday should be vaccinated with a single dose.
? Persons 13 years of age and older who have not had chickenpox should get two doses of the vaccine 4 to 8 weeks apart.
Vaccination precautions include:
? Pregnant women should not receive the vaccine, and non-pregnant women of childbearing age should avoid pregnancy for 1 month following vaccination.
? People who have serious reactions to neomycin or gelatin should not receive the vaccine.
? If you currently have a serious illness, are pregnant, or unable to fight off serious infection due to depressed immune function (cancer, long term steroid use, or HIV, etc.) it is best not to receive the vaccine.
? You should avoid the vaccine if you have received blood products (a transfusion, immune globulin, etc) within the past 5 months.
The chickenpox vaccine has a good safety record. The most common side effects are redness and soreness at the vaccination site or a mild rash and fever. These are generally mild and last only a few days. Severe reactions to the vaccine are rare (about 1 in 50,000 doses).
The vaccine is very effective and results in complete immunity for 8-9 out of 10 persons vaccinated. As with any new vaccine, the length of immunity can only be determined for as long as the vaccine has been tested. The dates gathered from the U.S. and Japan indicates that immunity lasts for at least 25 years.
The chickenpox vaccine is on the list of required vaccines for Texas school children. Exemptions are allowed only if there is written documentation that your child has had chickenpox. Exemptions can also be granted on religious or medical grounds.
For more information about the varicella vaccine or other immunizations call the National Immunization Hotline at (800) 232-2522. You can also log-on to the Center for Disease Control website at http://www.cdc.gov/nip/vaccine.htm .
Patricia Henderson, MS, RN, C-FNP
Family Nurse Practitioner
Center for Family and Preventive Medicine
Affiliate of San Jacinto Methodist Hospital
14626 FM 2100, Ste. C, Crosby, Texas