Chickenpox (varicella) fact sheet
What is chickenpox?
Chickenpox (varicella) is a highly contagious disease caused by the varicella-zoster virus. It is usually a mild childhood illness, but can be serious for non-immune pregnant women, newborn babies and people with weakened immune systems.
What are the symptoms?
Symptoms are usually a fever, feeling unwell and an itchy skin rash. The rash begins on the middle of the body and spreads all over forming blisters which crust over and dry out in about five days.
Chickenpox can cause problems such as: skin infection, dehydration, scarring and in rare cases, an infection in the lungs (pneumonia) or swelling of the brain.
High risk groups for severe chickenpox include:
- Pregnant women who have not had chickenpox (or been immunised against chickenpox). The baby can be seriously affected in all stages of pregnancy including after birth.
- Babies less than 1 month old.
- People with weakened immune systems such as those with cancer or receiving chemotherapy.
- Adults who have not had chickenpox and have not been immunised.
How is it spread?
An infected person can easily spread chickenpox through the air when coughing and sneezing, and by touching the blisters.
An infected person is contagious from two days before the rash starts until all of their blisters have formed crusty scabs.
The time from contact with chickenpox to getting sick (incubation period) is usually about 14-16 days, but can range from 10-21 days.
How is it diagnosed?
It is important that the illness is diagnosed by a doctor. This is usually based on what the rash looks like. Sometimes the doctor may order a test to confirm the diagnosis. A sample of the blister fluid is the most common test performed by a laboratory although a blood test may also be taken.
How is it treated?
In most cases people recover without needing treatment. Medications may be used in severe cases.
Ways to ease symptoms include:
- bed rest
- paracetamol to bring down the fever
- lukewarm baths, skin moisturisers, calamine lotion, mittens to prevent scratching.
How is it prevented?
Immunisation is available through general practitioners (for adults and children) and some local councils (for children).
Covering the mouth and nose with tissues when coughing or sneezing, regular hand-washing, and not sharing eating utensils or drink cups may also help reduce the spread of chickenpox.
Who should get immunised?
A vaccine against chickenpox is provided free under the National Immunisation Program to:
- Children aged 18 months (given with measles, mumps and rubella vaccine)
It is safe for these children to receive a vaccine even if they have had chickenpox
Vaccination is strongly encouraged for the following people if they have not had chickenpox:
- Healthcare workers, teachers, childcare workers and staff working in long term care facilities.
- Non-pregnant women of child-bearing age.
- People who share a house with someone who has a weak immune system.
What should I do if I have had contact with someone who has chicken pox?
If you believe you have not had chickenpox, and you have not been vaccinated, then you should see your doctor. Vaccination given within five days after exposure can prevent chickenpox (this should preferably be given within three days if possible).
The following people should see a doctor urgently if they have come into contact with chickenpox and have not had it themselves (and have not been immunised):
- Pregnant women
- Babies less than 1 month old
- People who have a weakened immune system
These groups may be advised by their doctor to have an injection of zoster immunoglobulin (ZIG).
Some people who have been immunised do develop chickenpox after contact with the virus. In this situation chickenpox is usually mild because the vaccination still provides some protection.
Although not funded under the National Immunisation Program, a 2nd dose of varicella vaccine can be purchased on a private script to provide enhanced protection.
What should I do if I have chickenpox?
You are contagious until all of the skin blisters have crusted and scabbed over, around five days.
Whilst contagious, children should be excluded from childcare or school. Adults should be excluded from work. Avoid close contact with pregnant women, children less than 18 months of age, people with a weakened immune system. Avoid public places until all of the blisters have crusted over.
If you are pregnant and develop chickenpox you should see an obstetrician as soon as possible.
When you go to your doctor or if you need to go to an Emergency Department at a hospital, you should ring ahead. This is to avoid waiting rooms and the possibility of infecting other people.
To speak to a Clinical Nurse Consultant, call the Public Health Hotline on 1800 671 738.