Croup

Croup

Croup is a viral illness in young children which causes narrowing of the upper airways. Croup is often a mild illness but can quickly become serious, so do not hesitate to get medical help.

Key points to remember about croup

Croup is often a mild illness but can quickly become serious, so do not hesitate to get medical help.

  • croup is a viral illness in young children which causes narrowing of the upper airways
  • croup is often worse at night
  • croup is often a mild illness but can quickly become serious, so do not hesitate to get medical help
  • if your child has stridor (a harsh noise heard when breathing in) while they are calm and not upset, take them to your doctor or the nearest hospital straight away
  • if there is severe breathing difficulty or distress, or your child becomes blue, pale or drowsy, dial 111 within New Zealand for urgent medical help (use the appropriate emergency number in other countries)
  • there is effective treatment for severe episodes of croup
  • steam doesn't help and may lead to accidental burns – do not use it

What is croup?

Croup is a viral illness in young children, which causes narrowing of the upper airways. Some children have recurrent croup and this may require further assessment.

How does croup develop?

When you breathe, air passes through the voice box (larynx) and windpipe (trachea) into the lungs. In croup, a viral infection causes inflammation and swelling of the lining of the voice box and windpipe, which become narrowed. When the airway becomes narrowed, breathing in becomes more difficult and stridor (a harsh noise when breathing in) is heard.

Who gets croup?

Toddlers are most likely to get croup. 

Toddlers are most likely to get croup. Their windpipes are softer than those of older children. When the airways become inflamed, they narrow and this results in stridor. If your child gets croup and is less than 6 months of age, or of school age, you should discuss it with your family doctor. 

What are the signs and symptoms of croup?

The major features are:

  • a cough which is harsh and often described as 'barking'
  • stridor (noisy breathing, with a harsh sound heard as your child breathes in)

Stridor may only last for a few days while the cough may last for up to a week or so. Your child's voice is usually hoarse. Breathing becomes more difficult and the stridor worsens when your child becomes upset. 

The symptoms of croup seem to most often appear or worsen at night. Before the cough and breathing trouble develop, your child may have other signs of the viral illness such as:

  • a sore throat
  • a temperature
  • red eyes
  • a runny nose, or
  • a poor appetite

What is the treatment?

Croup is caused by viruses, so antibiotics do not help.

Mild cases of croup can be managed at home and no medication is needed.

In moderate to severe croup, steroid medication is an effective treatment given by doctors. This reduces the swelling in your child's airway and helps them to breathe more easily. It does not change the cough but does reduce the stridor (the harsh noise heard when your child breathes in) which is the most serious aspect of the illness. Steroids work for about 48 hours.

In the most severe cases, nebulised adrenaline may also be given.

How can I care for my child at home?

If you are caring for your child with mild croup at home:

  • and they become upset, try to calm and comfort your child on your lap – distress can worsen the breathing difficulty and stridor (the harsh noise heard when your child breathes in)
  • allow your child to breathe cold air from outside by opening a window or door; make sure they are wrapped warmly and don't get chilled
  • cool sips of fluid may be soothing if your child's throat is sore
  • you can give paracetamol if your child is miserable with a fever or has a sore throat. (You must follow the dosage instructions on the bottle. It is dangerous to give more than the recommended dose)
  • if their croup gets worse and you are worried that it might be serious, take your child to their doctor, the nearest accident and emergency clinic or the nearest hospital emergency department for help 

Although adding steam to the air (humidification) used to be recommended, there is no evidence it actually helps, and there have been several cases reported where children have been badly burned from the hot water. For these reasons, we do not recommend using steam for croup.

How long does croup last?

Croup is usually at its worst in the first few days of the illness.

Generally, croup is at its worst in the first few days of the illness. Stridor (the harsh noise heard when your child breathes in) may only last for a few days while the cough may last for up to a week or so.

When should I seek help?

If your child has any of the following, go to a doctor or the nearest hospital straight away:

  • there is stridor (a harsh noise heard when breathing in) when your child is calm and not upset
  • you are worried your child is having increasing difficulty with their breathing
  • your child becomes persistently upset and can't be consoled
  • your child has additional signs of ill health (such as pale colour, a very high temperature, cool or clammy hands and feet, or dribbling)
  • you become concerned for any other reason

Dial 111 within New Zealand (use the appropriate emergency number in other countries) and ask for urgent medical help if your child has any of the following:

  • becomes blue
  • becomes pale or blue after a coughing spell
  • has extreme difficulty breathing
  • there is a change in their behaviour (for example, they become drowsy, agitated or delirious)
  • has pauses in breathing

In babies less than 6 months of age, or in children older than 6 years, croup is less common. There could be another reason for their symptoms and therefore review by your family doctor is necessary. In some cases a referral to a paediatrician (a specialist in children's health) or ENT (ear, nose and throat) specialist may be required.

What happens if my child gets recurrent croup?

It is very uncommon for children to have more than one episode of croup per year for their first 2 or 3 years. If your child does have recurrent symptoms of stridor (a harsh noise heard when breathing in), or barking cough (that is, several episodes each year, or episodes that continue into school age) then they should be reviewed by your family doctor. The need for a second opinion from a paediatrician (specialist in children’s health) or ENT (ear, nose and throat) specialist may be required.

Starship Foundation and the Paediatric Society of New Zealand acknowledge the cooperation of the Starship Respiratory Service at Starship Children's Health in making this content available to patients and families.

This page last reviewed 06 October 2015.
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