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If your child is struggling to breathe call triple zero (000) immediately and ask for an ambulance.

Key facts

  • Croup is an infection caused by a virus. It commonly causes swelling of the voice box (larynx) and the windpipe (trachea).
  • Children with croup often have a distinctive, harsh, ‘seal bark’ sounding cough.
  • Croup can cause stridor — noisy, high-pitched breathing, especially when the child breaths in.
  • In most children, croup is a mild infection which generally clears within 4 days.
  • Croup can quickly cause breathing problems which require urgent medical assistance.
  • Croup is more common in winter when symptoms peak in the evenings and overnight.

What is croup?

Croup is a viral infection in babies and young children which causes swelling of the voice box and airways. There is no specific treatment, especially for mild croup. However, it can cause narrowing of the airways. If a child is having problems breathing, they may need steroid medications to reduce the swelling and make it easier for them to breathe.

Some children can have a condition known as ‘spasmodic croup’, even when they don’t have any other cold symptoms. Coughing episodes generally occur at night with symptoms settling in around one hour. Spasmodic croup is more common in children with asthma, or with a family history of allergy and asthma.

What causes croup and how is it spread?

Croup can be caused by a number of viruses, some of the more common being respiratory syncytial virus (RSA), influenza virus, adenovirus and enteroviruses. Croup can also be caused by allergies or a bacterial infection, which is easily spread through coughing and sneezing. Because croup is so contagious, it’s important that children who have croup are kept away from others.

Not all children who are exposed to the virus will progress to getting croup. However, it is one of the most common respiratory illnesses in young children aged from 6 months to 5 years of age.

What are the symptoms of croup?

Croup can develop quickly, often in the middle of the night. This is when they symptoms are often worse, especially on the second and third night of having symptoms.

  • Croup generally starts with cold or flu symptoms.
  • During the day, children can appear generally well, apart from cold symptoms, though they can develop a harsh, barking cough and noisy breathing at night.
  • An elevated temperature, runny nose, and cough are the most common symptoms.
  • A croup cough has a distinctive ‘bark’ sound, much like a ‘seal’s bark’.
  • A hoarse voice when crying or talking.
  • A high-pitched noise ‘stridor’ when breathing air in.
  • If croup is severe, the skin in between the child’s ribs or under their neck may be drawn in when they breathe. This is called ‘intercostal recession’.
  • Most children with croup improve after a few days. Sometimes the symptoms can last for up to a week though coughing can last longer.

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

How is croup diagnosed?

Croup is generally diagnosed by assessing the child’s symptoms. Because the cough is so distinctive, croup is often suspected by parents, even before their child has had a physical examination.

How is croup treated?

Most children with croup recover at home without any special treatment. Staying away from other children and keeping them calm and rested is often helpful. A healthy diet helps the immune system to support recovery. However, many children lose their appetite when they are unwell. In the short term, this isn’t a problem. But it’s important to make sure they stay well hydrated with plenty of fluids when they are sick.

Paracetamol can be helpful to relieve a high fever or sore throat, though it’s important to give the correct dose, according to your child's weight and only as directed by your doctor.

Because croup is caused by a virus, treatment with antibiotics does not help. For children who need hospital care to help with their breathing, oral steroid medication as well as adrenaline through a nebuliser (mask) can help to reduce airway swelling.

Steam and humidifiers used to be a common treatment at home for croup, though they are not currently recommended. There is no evidence proving they are effective.

When should I see a doctor about my child’s croup?

It’s generally wise to see a doctor any time you’re worried about your child. But there are certain times when it’s more important to get medical help as soon as possible.

Have your child checked by a doctor if:

  • they are aged less than 6 months old and have signs and symptoms of croup
  • their breastbone or the skin in between their ribs is drawn in when they breathe
  • they have stridor (noisy breathing) even when they are resting
  • they are very distressed or their symptoms are getting worse
  • you are worried about any other symptoms

When should I call an ambulance?

Call an ambulance immediately if your child:

  • looks like they are struggling to breathe
  • looks very sick, is sleepy and their skin is pale
  • has a blue colour change to their lips
  • starts dribbling and cannot swallow

Croup can get worse quickly, it’s important to seek medical help if you’re child shows signs they are struggling to breathe.

Can croup be prevented?

There is no specific prevention for croup. There are several viruses which can cause croup, and it can be hard to know which specific virus causes the condition, though treatment is generally the same.

There is no immunisation to prevent croup. However, immunisation against influenza is recommended and can help to prevent croup caused by the influenza virus.

What you can do

There is no way to prevent children from getting croup. However, you can try to limit the spread of the viruses that cause croup by doing the following:

  • Try to avoid your child having contact with children who appear to be unwell or have ‘cold’ symptoms.
  • Wash your child’s hands before they eat.
  • Throw away used tissues immediately.
  • Teach your child (if they’re old enough) to cough and sneeze into their elbow or a tissue.
  • Encourage your child not to touch their nose, eyes or mouth with their fingers.
  • Clean surfaces regularly.
  • Be careful about your own hygiene and general health.
  • Offer your child a healthy and nutritious diet which will help to support their immune system.

Are there any complications from croup?

There are generally no complications from having croup. There is no permanent damage after a child has an episode of croup.

Speak to a maternal child health nurse

Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available 7am to midnight (AET), 7 days a week.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: September 2022

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Need more information?

Croup & stridor: babies & children | Raising Children Network

If your child has a barking cough, hoarse voice and stridor (noisy breathing), they might have croup. Most children with croup don’t need special treatment.

Read more on website

Croup: symptoms and treatments -

Croup is an infectious condition that causes inflammation of the voice box (larynx) and airways, resulting in breathing difficulties and a barking cough.

Read more on myDr website

Croup - Better Health Channel

Croup is a viral infection of the throat and windpipe that causes noisy breathing, a hoarse voice and a harsh, barking cough.

Read more on Better Health Channel website

Epiglottitis in babies, children & teens | Raising Children Network

Epiglottitis is a serious condition that affects children’s windpipes. If your well child suddenly develops breathing problems, get emergency medical help.

Read more on website

Call us and speak to a Maternal Child Health Nurse for personal advice and guidance.

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