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What is chickenpox?
Chickenpox is a highly contagious skin rash illness caused by a virus.

How is chickenpox spread?
It is primarily spread by coughing and sneezing, but may also spread by direct contact with an infected person or contact with an object that has touched a blister’s fluid (shirts, pants, etc.)

What are the symptoms of chickenpox?
Chickenpox begins with a rash that looks like pimples or insect bites, and usually a low fever.  The rash usually appears on the face, scalp, and body, but may also appear in the mouth or on the eyes.  Over time, the rash develops into bigger blisters that break, leaving open sores that dry and crust into scabs.  The rash appears in crops, and patients can have beginning pimples, bigger blisters, and scabs all at the same time.  Children usually have 200-500 lesions in 2-4 crops.

How long does chickenpox last for?
Chickenpox lasts between a few days and 2 weeks.

How soon after exposure do symptoms occur?
Symptoms usually show up 14-16 days after exposure, with a range of 10-21 days.

Is chickenpox serious?
In healthy children the disease is generally mild. Adults have more severe disease and more complications. Certain high-risk individuals including immunocompromised children, susceptible pregnant females, and premature infants of less than 28 weeks gestation may have severe complications of the disease.

What are the complications associated with chickenpox?
The most common complications of chickenpox include bacterial infections of skin lesions, dehydration, pneumonia (usually viral), and central nervous system (CNS) involvement. CNS involvement can be very serious and may lead to seizures and coma. Reye syndrome is a rare complication that occurs in children with chickenpox or influenza that have taken aspirin. The cause of Reye syndrome is unknown.

Can a person get chickenpox again?
Recovery from chickenpox usually results in lifetime immunity, and a second infection is rare. Shingles, a disease caused by the same virus, may occur in persons who have already had chickenpox.

What is the treatment for chickenpox?
Several antiviral drugs are active against chickenpox. However, antiviral drugs will not decrease transmission of chickenpox to others, reduce the number of days missed at school, or reduce complications. Antiviral drugs are not recommended for healthy infants and children.

What can be done to prevent the spread of chickenpox?
Vaccination is the best way to prevent chickenpox.

When should someone be vaccinated for chickenpox?
The chickenpox vaccine was licensed for use in the US in 1995.

• All children <13 years of age should routinely be given two doses of chickenpox vaccine. The first dose should be given at 12-15 months of age and the second at 4-6 years of age. A second dose catch-up chickenpox vaccination is recommended for children and adolescents who previously have received one dose.
• All individuals ≥13 years of age without evidence of immunity should be vaccinated with two doses of chickenpox vaccine separated by 4-8 weeks.

One dose of chickenpox vaccine is 80%–85% effective against infection. Sometimes breakthrough disease (chickenpox in a vaccinated person) can occur, but is usually milder with fewer lesions. In order to prevent breakthrough disease, a second dose is recommended.

Is chickenpox vaccine safe?
Most people who receive the chickenpox vaccine do not have any problems with it. Since the vaccine was approved in 1995, the most common post-vaccination complaints include pain, soreness, redness, or swelling at the injection site. A chickenpox-like rash (usually less than 5 lesions) has been reported very rarely in some persons after vaccination. There is no evidence to suggest that any serious complications are connected with chickenpox vaccination. Since the vaccine was approved, the number of cases of chickenpox occurring in the United States has declined by 83-93%.
There have been a few reported cases of persons developing shingles because of the vaccine virus; however, the risk of developing shingles after vaccination is less than the risk of developing shingles from a natural chickenpox infection.

What is shingles?
Shingles is an infection caused by the same virus that causes chickenpox. It is also called Herpes Zoster. Shingles causes a painful rash. Some people with shingles develop post-herpetic neuralgia, a remarkably painful chronic condition that may continue for a year after the rash has healed. Anyone who has recovered from chickenpox can develop shingles; however it is most common in persons 50 years and older. Shingles is not contagious; however, a person who has never had chickenpox or chickenpox vaccine may develop chickenpox if exposed to someone with shingles. The virus can only be transmitted by direct contact in this situation.

Where can I get further information?

• Your personal doctor
• Your local health department, listed in your telephone directory
• The Utah Department of Health, Immunization Program (801) 538-9450 or the Office of Epidemiology (801) 538-6191.
  

Utah Department of Health
May 4, 2007