What is chickenpox?

Chickenpox is a common, highly infectious viral condition. If infected, a person develops a rash of itchy red spots. Chickenpox is usually mild and generally occurs during childhood although it can appear at any stage of life. However, chickenpox is also associated with severe complications — and even death — so it should be treated seriously in all cases.

What are the symptoms of chickenpox?

New spots may keep appearing in waves for 3 to 5 days after the rash begins. Different clusters of spots may therefore be at different stages of blistering or drying out.

These scabs don't leave scars unless they're badly infected.

Chickenpox in adults

Chickenpox is generally a childhood illness, but people of any age can still get it. While chickenpox can cause serious complications at any age, it tends to be more severe in adults than in children.

Anyone with chickenpox should remain isolated from other people until all the spots have crusted over. This will mean taking time off work and restricting social interactions, while children will need to stay home from school and childcare. You should seek medical advice if you develop any abnormal symptoms, such as infected blisters.

Adults with chickenpox may benefit from taking antiviral medicine if treatment can be started early in the course of the illness.

Pregnant women should be especially careful to avoid chickenpox since it can affect their unborn baby by causing fetal malformations, skin scarring and other serious problems. This is known as congenital varicella syndrome.

Unusual symptoms

Most healthy children and adults recover from chickenpox, with no lasting ill effects, simply by resting, just as with cold or flu.

Some are unlucky, however, and have a more severe case of chickenpox than is usual. The complications of the disease can be serious, and even fatal.

Contact your doctor straight away if you or your child develop any abnormal symptoms. These include:

• if the skin surrounding the blisters becomes red and painful
• if you or your child start to get pain in the chest or have difficulty breathing
• if you or your child become drowsy, develop severe headaches or have trouble with co-ordination
• if you or your child are becoming more unwell, not better, as was expected

In some cases, prescription medicine and possibly hospital treatment may be needed.

The varicella virus that causes chickenpox can be reactivated many years after the initial infection and cause shingles (herpes zoster).

CHECK YOUR SYMPTOMS — Use our skin problems Symptom Checker and find out if you need to seek medical help.

What causes chickenpox?

Chickenpox is caused by the varicella zoster virus. It can be spread either through close person-to-person contact, or through sneezing and coughing – just like a cold or flu. Later in the illness, the virus is spread by direct contact with the fluid in the blisters. Chickenpox infection triggers an immune response and people usually don’t get it twice.

The infection is highly contagious to people who have never had chickenpox or who have not been vaccinated. You can also catch the virus by handling items and surfaces that have been contaminated and then transferring the virus to yourself by touching your face.

Children and adults who have not had chickenpox can develop it if they come into contact with someone who has shingles. But if someone has already had chickenpox and they come into contact with another person who has shingles, they may develop shingles too (but not chickenpox).

How is chickenpox diagnosed?

You or your child should not usually need any medical tests to be diagnosed with chickenpox. You can be fairly sure that it is chickenpox if you have the key symptoms: a mild fever followed by an itchy rash, blisters and scabs. Chickenpox is a common viral illness that can have serious complications so seek help if you are unsure.

The chickenpox spots are usually distinctive enough that you won’t confuse them with other rashes, although occasionally they can be confused with other conditions that affect the skin. These include some insect bites or scabies (a contagious skin condition that causes intense itching).

If you're still uncertain about what is causing your symptoms, see your doctor.

If you or your child are exposed to chickenpox

If you or your child are exposed to chickenpox, your doctor may order a test to see if you or they are already immune to the condition.

If you have had chickenpox in the past, then it is extremely unlikely that you will develop chickenpox for a second time. If you've never had chickenpox, or you're unsure whether you've had it, then you may need an immunity test. This is a blood test that checks whether you are producing the antibodies to the chickenpox virus.

If your blood test result shows that you have the antibodies, you'll be naturally protected from the virus. If you don't have the antibodies, then you'll need to be monitored closely to see if you develop chickenpox symptoms. A post-exposure vaccination can reduce the risk of developing chickenpox.

How is chickenpox treated?

You don't need to go to your doctor or emergency department unless you're not sure that it's chickenpox or your child is very unwell or distressed. There's no cure or specific treatment for chickenpox. Treatment is geared towards relieving the symptoms:

• Make sure that you (or your child) have plenty to drink.
• Use paracetamol to relieve the fever and discomfort.
• Baths, loose comfortable clothes and calamine lotion can all ease the itchiness. Gauze pads soaked in bicarbonate of soda and water and then placed over the sores can also calm the itch for a while.
• It’s important not to scratch or pick at the spots since this will increase the risk of scarring. It's hard for children to do this, so give them plenty of praise and encouragement. Distractions, such as TV, are good for taking their mind off the itching. Cut and blunt fingernails so they are short to reduce the abrasion from scratching and risk of bacterial infection.
• Anyone with chickenpox should remain isolated from other people until all the spots have crusted over. Stay home from work, or let your child's day care or school know that they are ill, in case other children are at risk. Keep your child away from day care or school until the last blister has scabbed over.

Pregnancy and chickenpox contact

It’s especially important that someone with chickenpox stays away from pregnant women and those trying to get pregnant. If either you or your child has had contact with a pregnant woman just before they became unwell, let the woman know about the chickenpox and suggest that she sees her doctor or midwife.

In women who have never had chickenpox, catching the virus during pregnancy can cause miscarriage or the baby may be born with complications caused by the chickenpox.

When should I see my doctor?

See your doctor if you are unsure whether you or your child has chickenpox.

Contact your doctor immediately if you have been in contact with someone who has chickenpox or if you have chickenpox symptoms and:

• you are pregnant
• you have a weakened immune system (the body's defence system)
• you have a baby who is less than 4 weeks old
• you are breastfeeding

Chickenpox in these instances can cause serious complications if left untreated. It is essential to seek medical advice so that you can receive any necessary treatment.

Your doctor can also advise about whether you should continue breastfeeding your baby.

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Can chickenpox be prevented?

The best way to avoid chickenpox is to have your child immunised. Chickenpox vaccination is recommended as part of routine childhood immunisation to help prevent the disease.

Chickenpox vaccine is now given free as part of the government immunisation program. It is free under the National Immunisation Program Schedule. To receive immunisation, visit your local doctor or immunisation provider. Remember that although the vaccine is provided at no cost, a consultation fee may apply.

The chickenpox vaccination is given on its own or combined with vaccination for measles, mumps and rubella. A catch-up program is available for children aged around 12 to 13 years who have not had chickenpox or received the varicella vaccine.

If you are an adult who has never had chickenpox and you haven’t been vaccinated, talk to your doctor about whether you need a catch-up vaccine.

The vaccine should not be given to pregnant women, people whose immune systems are affected by a medical condition or who are taking high doses of immune suppressing medicine or people who have had an anaphylaxis after receiving the chickenpox vaccine in the past.

Chickenpox vaccination

Vaccination is your best protection against chickenpox. This table explains how the vaccine is given, who should get it, and whether it is on the National Immunisation Program Schedule. Some diseases can be prevented with different vaccines, so talk to your doctor about which one is appropriate for you.

At what age is vaccination for chickenpox recommended?	In children aged 12 months to 14 years. In adolescents aged over 14 and adults who have not received 2 doses of varicella-containing vaccine, particularly healthcare workers, childhood educators and carers and people who work in long-term care facilities.
How is it administered?	The vaccine is given by injection.
Is it free?	Vaccination is free for children at age 18 months and people under 20 years old, refugees and other humanitarian entrants to Australia of any age. Find out more on the Department of Health website and the National Immunisation Program Schedule. Ask your doctor whether you are eligible for additional free vaccines based on your situation or location.
Common side effects	The vaccine is very safe. The most common side effects are pain, redness or swelling where the needle went in, rash and fever. Very rarely, people who have had the vaccine may develop shingles.

To minimise the risk of infection, avoid close contact with people who have chickenpox.

If you or someone close to you has chickenpox, then remain isolated from others to prevent cross-infection. This means taking time off work and temporarily avoiding social contact, attending school or care until all blisters have dried up, which is usually around 5 days after the rash first appeared. Check with your doctor for how long you or your child needs to remain isolated if you are unsure.

Complications of chickenpox

Chickenpox can be severe at any age and can have serious complications. These complications include:

• bacterial skin infections
• pneumonia
• swelling of the membranes that cover the brain (aseptic meningitis)
• a decrease in blood platelet cells (thrombocytopenia)
• bleeding problems
• infection of the blood (sepsis)
• inflammation or infection of the brain (encephalitis)
• trouble with balance and co-ordination (cerebellar ataxia)
• fetal abnormalities in pregnant women (see below)
• dehydration

Pregnant women should be especially careful to avoid chickenpox since it can affect the unborn baby by causing fetal malformations, skin scarring and other serious problems. This is known as congenital varicella syndrome.

Other questions you might have

What does chickenpox look like?

The chickenpox rash starts as small, itchy red spots, then the spots develop a blister on top and become intensely itchy. After a day or two, the fluid in the blisters gets cloudy and they begin to dry out and crust over.

How long are you infectious with chickenpox?

Chickenpox is infectious from 2 days before the spots appear until they have crusted over, usually 5 days after they first appeared.

Should I take my child to the doctor if they have chickenpox?

Chickenpox is a common viral illness that can have serious complications, so see your doctor if you are unsure.

Resources and support

Visit the Chickenpox immunisation service for more information about the chickenpox vaccine.

Other languages

Do you prefer other languages than English? This website offers translated information:

• Health Translations, Victoria: Measles, mumps, rubella and chickenpox immunisation information (in more than 15 languages)

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