What is chickenpox?

Chickenpox is a very contagious infection caused by the varicella zoster virus. Most people with chickenpox have mild symptoms and recover quickly. In rare cases, the virus can cause serious complications such as pneumonia or meningitis.

The chickenpox vaccine was added to the Australian National Immunisation Program in 2005. Since then, there have been far fewer hospitalisations and deaths due to chickenpox in Australia. Immunisation prevents most cases of chickenpox and reduces the chance of serious illness and complications.

This page focuses on advice for adults and children above 5 years of age. You can find information about chickenpox during pregnancy and in babies and younger children on the Pregnancy, Birth and Baby website.

What are the symptoms of chickenpox?

The main symptom of chickenpox is an itchy red rash. During the illness, the rash turns into fluid-filled blisters that may burst and crust over.

People with chickenpox may also have these symptoms:

• fever
• headache
• feeling generally unwell

Symptoms usually start about 2 weeks after being around someone with chickenpox, and they can continue for between 10 days and 3 weeks.

Chickenpox is more common in children, but when adults catch chickenpox, they usually experience a more severe illness and can take longer to recover.

What causes chickenpox and how is it spread?

Chickenpox is caused by the varicella zoster virus. You are most likely to catch chickenpox if you come into contact with an infected person’s respiratory fluids — for example, when they cough or sneeze nearby. You can also catch chickenpox by touching fluid from an infected person’s chickenpox blister.

If you have chickenpox, you should stay home from childcare, school or work to avoid spreading the infection to others while you are contagious. Chickenpox is no longer contagious once the blisters have crusted over.

Who is at risk of chickenpox?

Chickenpox is very contagious for anyone who is not immune. Most people who are immune —who have had the vaccine or have had chickenpox in the past — will not catch it, even if they are near someone with chickenpox.

Chickenpox can be especially dangerous for some groups of people, including:

• pregnant women
• newborn babies
• people with weakened immune systems, such as patients receiving chemotherapy

If you are in one of these groups, you should see your doctor if you have been near someone with chickenpox — even if you have no symptoms so far. In some cases, your doctor may prescribe medicines to reduce the chance of your becoming infected, or reduce the severity of the illness if you do become infected.

Chickenpox and pregnancy

Chickenpox is particularly dangerous for pregnant women and their babies. Women who have chickenpox for the first time during pregnancy are more likely to develop a serious illness and complications. Babies of pregnant women with chickenpox can be born with severe chickenpox as well as birth defects affecting their skin, eyes, arms, legs or nervous system.

If you are planning a pregnancy, see your doctor for advice about pre-conception screening for immunity to chickenpox, and ask about getting vaccinated. The chickenpox vaccine is not recommended during pregnancy, so it’s better to get the vaccine before you get pregnant.

When should I see my doctor?

The main symptom of chickenpox is an itchy red rash, which is also an early sign of a range of other conditions. You should see your doctor if you have symptoms of chickenpox to be sure you are diagnosed correctly.

Because chickenpox is so contagious, you should call your doctor before your visit, or tell the reception staff when you arrive, so you can be seated away from other people.

You should see your doctor urgently if you have severe symptoms, including:

• high fever
• neck pain
• difficulty breathing
• sore, red areas around blisters

Severe symptoms may be a sign of complications due to chickenpox that need medical treatment.

Chickenpox is a notifiable disease in most states. This means that your doctor must report cases of chickenpox to the local health authorities, who can help control an outbreak if needed.

How is chickenpox diagnosed?

Chickenpox is usually diagnosed by a doctor when they examine your skin rash. Your doctor may also ask if you’ve had recent contact with anyone who has chickenpox and about your vaccination history.

In some cases, they may do tests on fluid from your blisters or blood tests to confirm that you have chickenpox.

How is chickenpox treated?

There is no specific medicine or treatment available to treat chickenpox. Antibiotics will not help you recover because the illness is caused by a virus, not bacteria.

Most people with chickenpox have mild symptoms and recover quickly, but chickenpox can still be uncomfortable.

Chickenpox blisters can be very itchy, and it can be difficult to avoid scratching them — especially in the case of children. However, scratching increases the chance of blisters becoming infected and of leaving scars. Some people find it helpful to keep their fingernails short to make scratching more difficult.

You can also try to relieve your symptoms with these tips:

• Use lotions, such as calamine lotion, to reduce itching.
• Apply cool compresses to itchy blisters.
• Have lukewarm baths with baking soda or oatmeal added.
• Get plenty of rest.
• Take paracetamol to reduce fever — always follow the dose instructions on the packet.

Your doctor may prescribe an antiviral medicine if you are very unwell, or if you have a weakened immune system.

How can I prevent chickenpox?

The best way to prevent chickenpox is through vaccination.

Vaccination prevents a serious illness developing in most cases of chickenpox. In rare cases, if you catch chickenpox even after you have had the vaccine, your symptoms will usually be milder and will improve faster than if you had not been vaccinated.

You can receive the chickenpox vaccine on its own, or combined with vaccinations for measles, mumps and rubella (known as an MMR-V vaccination). Children can have the chickenpox vaccine for free on the National Immunisation Program Schedule at 18 months of age.

MMR vaccinations don’t cause autism. Medical and scientific experts have completely discredited any research that might have suggested a link between the MMR vaccine and autism.

If you have never had chickenpox and never had the chickenpox vaccine, speak to your doctor about getting vaccinated.

Vaccination against chickenpox is strongly recommended for people who work in childcare, aged care or healthcare since they are more likely to be exposed to infection.

The chickenpox vaccine is not recommended when you are pregnant or for people who have a weakened immune system.

What complications can come with chickenpox?

Complications associated with chickenpox are rare, but they can be serious and have life-long effects. They can include:

They can include:

• bacterial infection of skin blisters
• scarring
• lung infection (pneumonia)
• inflammation of the brain or the lining of the brain (meningitis or encephalitis)

If your chickenpox blisters become infected, your doctor may prescribe you an antibiotic cream or antibiotic tablets to treat the infection.

If you have been diagnosed with chickenpox and are concerned about other complications, speak to your doctor.

If someone experiences side effects after being vaccinated against chickenpox, they usually occur about a week after receiving the vaccine, but they pass quickly.

Resources and support

• For more information about immunisation in Australia, visit the Department of Health Immunisation website.
• The Sharing Knowledge About Immunisation website has videos and other tools to help you make decisions about immunisation and your family.