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Croup is a condition caused by a viral infection. The virus leads to swelling of the voice box (larynx) and windpipe (trachea). This swelling makes the airway narrower, so it is harder to breathe. Children with croup develop a harsh, barking cough and may make a noisy, high-pitched sound when they breathe in (stridor).
Croup mostly affects children between six months and five years old, but it can affect older children. Some children get croup several times.
Croup can get worse quickly. If your child is having problems breathing, seek urgent medical attention.
Croup often begins without warning, in the middle of the night. The symptoms are often worse at night, and are at their worst on the second or third night of the illness. The signs and symptoms of croup may last for three to four days; however, a cough may linger for up to three weeks. The stridor should not persist.
A mild attack of croup is when your child has the harsh, barking cough but does not have stridor when they are calm and settled, and they are not struggling to breathe. No medical treatment is necessary for mild croup, or the virus that has caused it. You can usually manage mild croup at home with the following care:
Steam and humidifiers are no longer recommended as treatment. There is no evidence to suggest they are beneficial.
You should call an ambulance immediately if:
You should see a doctor if:
If your child has mild croup that lasts for more than four days, or if stridor returns after your child has recovered from croup, take them to see a doctor.
Your doctor may prescribe steroids (e.g. prednisolone or dexamethasone) to be taken by mouth. The steroids help reduce the swelling in the airway, which will make breathing easier. Antibiotics do not work on viruses and are not given to children with croup.
If your child has severe croup, they will need to stay in hospital, where they will be closely watched.
Even though not all children get croup when infected by the virus, the virus that has caused the croup can be spread easily from person to person by coughing and sneezing. If your child has croup, you should keep them away from school and child care while they are unwell so that they don’t spread the virus that is causing the croup. Regularly washing hands thoroughly can help prevent the spread of viruses.
Should I use steam to treat croup?
No. In the past, some doctors recommended exposure to mist or steam therapy, including the use of vaporisers. Research evidence now shows this to be of no benefit and it is no longer recommended.
Developed by The Royal Children's Hospital General Medicine and Respiratory and Sleep Medicine departments, and Centre for Community Child Health. We acknowledge the input of RCH consumers and carers.
Reviewed August 2020.
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