Dr Phil Kieran: How can I help my child avoid croup?

Croup is the medical term for infections that cause swelling in the upper airways, particularly in the larynx (voice box).

My two-year-old son has needed to go to hospital twice with croup, and I now get worried every time he has a cough. I thought the summer would be a break from it, but my friend’s child just had croup. Is there anything I can do to prevent him from getting seriously ill with croup again?

Croup is the medical term for infections that cause swelling in the upper airways, particularly in the larynx (voice box). This is almost always a virus, and the most common cause is a parainfluenza virus. This means that croup is far more common in the autumn and winter months than at other times of the year, but, as you have mentioned, it can also happen in the summer.

Croup usually starts with a mild, cold-like illness, characterised by a runny nose, mild fever (around 38.5 °C), and, sometimes, sticky eyes. This can then progress to a cough, followed by the classic ‘seal bark’ croup cough. Once you have heard this cough, it is easy to recognise.

As a virus causes it, we don’t have any medication to help the child to clear it faster. Croup tends to worsen over the first three days and usually begins to improve about 48 hours after the barking cough starts. A cough can last from seven to 10 days.

The cough itself is not concerning, but the swelling that causes it can lead to breathing difficulties. This can cause a noise when the child is breathing, which we call stridor. It has been described as the sound of Darth Vader from Star Wars breathing or a scuba diver using an oxygen tank. This breathing difficulty can get more severe and should be evaluated by a doctor to check if treatment is necessary.

If your child looks like they are having a lot of difficulty breathing, if the stridor is noticeable when they are calm, or if their ribs appear to be sucking in when they breathe, seek medical attention immediately.

We treat croup with steroids. This reduces the swelling in the airway, while the immune system is fighting the infection. If the steroid is dexamethasone, it is a single dose which stays in the system for three days, or one dose per day for three days if it’s prednisolone, as this covers the period when the swelling is at its worst. This treatment is primarily intended to help with breathing and may not have any effect on the cough. So, if your child is still coughing when the medication is finished, it doesn’t mean they need more. For milder cases of croup, keeping the bedroom cooler at night can be helpful, as can helping the child stay calm.

To reduce the risk of croup, follow good respiratory hygiene. Try to avoid exposing them to others who are coughing or sick. Also, getting people to wash or sanitise their hands before holding your child is a good idea.

Most children will outgrow croup by the age of six, with the most severe cases typically occurring in children under three years old.

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