Causes of chickenpox

Chickenpox is caused by the Varicella zoster virus. It can be spread by direct person-to-person physical contact, or through sneezing and coughing.

An unimmunised child or a child with a very weak immune system who has direct physical contact with a shingles rash in an older person can develop chickenpox. This is because shingles is also caused by the Varicella zoster virus. But adults can’t get shingles from children with chickenpox.

Symptoms of chickenpox

Children and adults infected with the chickenpox virus don’t usually have symptoms until 2-3 weeks after contact.

In children, chickenpox usually starts with a general feeling of tiredness and lethargy, as well as a fever and swollen glands. Over the next 3-5 days, a rash breaks out.

At first, this rash appears as red spots, which develop into crops of small blisters over the chest, back, tummy or face. These soon appear on the rest of the body, and might even come up in the mouth or ears, or on the genitals or eyes. The blisters are extremely itchy, and new ones form as older ones scab over and dry up. The scabs can take several weeks to fall off.

The rash doesn’t leave any scars unless the blisters or scabs are scratched, or the sores get infected.

Chickenpox symptoms tend to be much milder in children than in adults.

Chickenpox is contagious from a few days before the rash appears until all the existing sores or blisters have formed scabs and are completely dry. This usually takes around a week.

Chickenpox complications

Healthy children probably won’t have any chickenpox complications. But complications do sometimes happen and include infection of skin sores, pneumonia and encephalitis.

Children who have low immunity – for example, children with cancer or who are taking immunosuppressant medication like high-dose steroids – can suffer severe attacks of chickenpox. These children need to be kept away from people with chickenpox or people who might have been infected with chickenpox but aren’t yet showing symptoms.

If your child has low immunity and has come into contact with a person with chickenpox, you should contact your doctor as soon as possible.

Treatment for chickenpox

Children with chickenpox usually need treatment only to relieve symptoms like the itch.

To help with the itch, soak gauze pads in bicarbonate of soda and water and put the pads over the sores. Creams like calamine lotion might also help. If your child really can’t stand the itching, your doctor might prescribe an antihistamine medicine.

Give paracetamol according to directions if your child is miserable with a fever.

Do not give aspirin to your child, because children with chickenpox who are treated with aspirin might develop Reye’s syndrome, a rare but very serious condition.

Children who have very severe chickenpox and who need to be hospitalised might be given anti-viral medication, most commonly acyclovir.

Keep your child away from child care, preschool or school until the last blister has scabbed over.

If your child has chickenpox, it can help to keep his nails short – if he does scratch, the sores are less likely to get infected. You could also put mittens on younger children.

Chickenpox prevention

The best way to avoid chickenpox is to have your child immunised.

As part of the Australian National Immunisation Program (NIP), your child will get free immunisation against chickenpox at 18 months old (unless she has already had chickenpox) or in year 7 of secondary school (if she hasn’t had a chickenpox immunisation or infection).

If your child is immunised and still gets chickenpox, the disease will be much milder.

Chickenpox immunisation is also recommended for children 14 years and older, as well as for adults who haven’t been immunised against chickenpox or who haven’t yet had the disease. This isn’t paid for under the NIP.