Chickenpox (varicella) is a very contagious illness caused by the varicella-zoster virus.
People of any age can get chickenpox, but it is most common in childhood.
Once a person is infected, the virus can remain dormant in the body and reappear later in life as shingles.
It usually causes mild illness in children. Symptoms usually appear 1 to 2 weeks after exposure.
Chickenpox typically begins with:
This is followed by a distinctive itchy rash that starts with red lumps that turn into fluid-filled blisters and then scabs. The rash typically starts to develop 1-2 days after early symptoms appear.
Complications can include:
Chickenpox is rarely fatal, but severe illness can occur in people at higher risk.
Anyone who has not had chickenpox or been vaccinated can get chickenpox. People at higher risk of severe illness include:
Chickenpox spreads easily by:
People are infectious from 1 to 2 days before the rash appears until all of the blisters have formed crusts or scabs.
Chickenpox during pregnancy may cause serious complications for both mother and baby.
During the first 28 weeks of pregnancy, your baby is at risk of fetal varicella syndrome. This can cause skin scarring, eye and limb abnormalities and brain damage.
During the last 4 weeks of pregnancy, the baby is at risk of neonatal varicella, which can be severe.
Vaccines are available for chickenpox and offer the best protection. While it's still possible to get chickenpox after vaccination, symptoms are usually milder and less contagious.
The chickenpox vaccine is called the varicella vaccine. You can get it on its own, or as part of the measles, mumps, rubella, varicella (MMRV) vaccine.
Doctors may recommend earlier vaccination before international travel or during an outbreak.
All vaccines can have side effects. Most side effects are mild and settle quickly.
Some people may have pain or redness at the injection site, fever or tiredness.
Occasionally, a mild rash may appear. If this happens, cover the rash until it has crusted over and avoid contact with people at high risk.
Although rare, some vaccinated children may still catch chickenpox, a condition called breakthrough chickenpox. However, research and clinical experience show that breakthrough infections are generally much milder than those in unvaccinated children.
Children with breakthrough chickenpox typically have:
A doctor can diagnose chickenpox based on your symptoms and by the appearance of the rash. Sometimes the diagnosis is confirmed by testing samples taken from the blisters of the rash or from a blood test.
People at higher risk of severe illness should speak to their doctor as soon as possible.
Most cases are mild and can be treated at home. Keep hydrated with water and other fluids and get plenty of rest.
Chickenpox blisters can be very itchy, so it can be hard to avoid scratching them, especially for children. However, if you scratch your blisters, they are more likely to become infected and leave scars.
You can ask your doctor for advice on how to manage symptoms. These can include treatments for pain and itch. Some people may need antiviral medicines to help them get better. Your doctor will let you know if you need antiviral medicine.
The varicella vaccine can also help protect people who are not immune and may be given up to five days after exposure.
Anyone exposed to chickenpox should monitor for symptoms up to 3 weeks and contact their doctor if any develop.
If you have concerns, please contact your doctor or call healthdirect on 1800 022 222.
People who have been diagnosed with chickenpox should:
The Multicultural Health Communication Service NSW (MHCS) provides translations for chickenpox and shingles in 13 languages other than English.