Introduction

Croup is a condition that most commonly happens when a child has a virus that causes the airways to swell and produce too much phlegm. It is more common during winter when more viruses are spreading. 

The airways that are mainly affected by croup include the following:

  • larynx – the voice box
  • trachea – the windpipe

When the airways swell and fill with phlegm, it becomes harder to breathe in and out. This can cause the trachea to collapse on itself – like sucking too hard on a blocked straw.

Croup will cause your child to have a rough cough that sounds like a bark and noisy breathing.

Croup is most common in children aged between 6 months and 3 years because their airways are smaller and softer. As children grow up, their airways become stronger, and they are less likely to be affected. 

 Signs and symptoms

Croup can last for a few days, and usually, the symptoms are worse at nighttime. Symptoms are generally worse during the first few days and can last up to a week. Your child may have a croup cough that lasts longer, but there will usually be no permanent damage.

Symptoms of croup include:

  • a raspy voice
  • a barking cough that causes their chest to go inwards
  • noisy or difficult breathing and a “crowing” sound, called stridor
  • difficulty breathing, especially when upset.

Viruses like the common cold cause croup, so your child may also have the following symptoms before croup develops:

  • a sore throat
  • fever
  • red eyes
  • runny nose.

Diagnosis

Your child’s doctor can diagnose croup based on their signs and symptoms and a physical examination.

Treatment

A virus usually causes croup, so antibiotics will not help. 

The doctor may give your child some oral steroid medication and adrenaline to reduce the swelling and help your child breathe more easily.

These medications are usually given using a nebuliser, a device that turns medications into a mist that your child can breathe in.

Most children do not need to be admitted to the hospital and can go home from the emergency department once treated.

 Management

Looking after your child at home

Your child might become stressed and upset when they have difficulty breathing, which can make it even more difficult to breathe properly.

Try to calm and comfort your child and encourage them to rest and drink plenty of fluids.

Do not use steam to treat your child’s croup or cold, as it can cause burns. There is no evidence that steam is effective in treating croup.

Spasmodic croup

Some children have many episodes of croup. These episodes usually happen at night and will usually settle after an hour.

This is sometimes called Spasmodic croup and can come on suddenly even when your child does not have a cold.

This form of croup is more common in children who either have asthma or have a family history of asthma and allergies.

When to seek help

If your child has any of the following symptoms, take them to a local doctor or a hospital emergency department straight away.

  • breathing is becoming more difficult
  • they are cyanotic after coughing, where the skin turns a pale blue colour because of a lack of oxygen in the blood
  • they are restless, irritable, or delirious 
  • you notice the area between their ribs being drawn in 
  • they have high-temperature 
  • they are dribbling or drooling more than usual
  • they are not drinking enough water
  • the stridor noise is heard when they breathe in and out, even when your child is resting
  • if you are worried that your child is getting worse.

Disclaimer

This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.


© Sydney Children’s Hospitals Network 2024