Dr Phil Kieran: Could my child's night coughing be due to asthma?

A prolonged cough is a common complaint and often causes significant distress to both the child with the cough and the parent who hears it. File picture: iStock 

My 12-year-old daughter has started coughing at night. Lying down seems to be a trigger. It’s a dry cough, so could it mean she has asthma rather than a lingering viral cough?

A prolonged cough is a common complaint and often causes significant distress to both the child with the cough and the parent who hears it.

Figuring out the underlying cause of a lingering cough can be difficult, take time, and often require a bit of trial and error. For most respiratory illnesses, whether viral or bacterial, it is normal for the cough to persist for a while after the child feels better.

In a well child with a mild enough cough, I wouldn’t be worried until the cough has been present for three weeks. After this point, I would consider other issues, but not necessarily worry about them.

A helpful way to gauge whether a cough is concerning is to consider its course, or trajectory. By this, I mean, is the cough getting better? Staying the same? Or getting worse?

If you are finding it tricky to tell, think about how frequent the cough is, how long it lasts, and how much it bothers your child. 

If these three areas are improving, the cough is likely due to an illness that is no longer active (such as a recent infection) and will likely settle down by itself. 

If the cough is getting worse, whatever the cause, it is likely becoming more severe, so seeing your GP is a good idea. If the cough is just hanging around and not changing, then there may be an underlying condition. 

A cough at night can be a sign of asthma. This is more likely for children who have a sibling with asthma or a history of asthma-associated conditions like eczema or allergies. A cough that occurs when lying down, as in your daughter’s case, may be a sign of excess nasal secretions (rhinitis), which drip and trigger a cough.

I would suggest bringing your daughter to the GP to see if there are any indications as to which of these causes is most likely.

When I see a child who has a strong likelihood of asthma or if I hear much wheeze when I examine them, we may consider a trial of asthma treatment. 

This would usually involve using a preventer inhaler for about three months and waiting to see if the symptoms settle down.

There are specific tests, such as pulmonary function tests, but most of the time, asthma is diagnosed clinically and confirmed by a successful response to treatment.

For difficult cases, we may consider referring your child for formal pulmonary function testing, but often this isn’t necessary.

If you have a question for GP Phil Kieran, please send it to [e-mail]