Q&A: What is asthma and how is it diagnosed in children?

Cause of disorder in children seems to be a combination of genetics and environment

It’s important to take the child to the GP if you have any concerns. Photograph: iStock

What causes asthma?

Asthma is an inflammatory disorder of the bronchial airways produced by allergies, viral respiratory infections and airborne irritants. The root cause is unknown but it seems that a combination of genetics and environment determines who is affected.

There was a very significant increase in the global incidence of asthma in the latter half of the 20th century, which seemed to level off, or even decrease, in the last decade, says Dr Marcus Butler, a respiratory consultant and medical director of the Asthma Society (asthma.ie). This trend would indicate that genetics is not the dominant factor.

What are the symptoms?


In children, it’s typically wheezing. They can also get a sudden increase in coughing that won’t go away. As they get older, children can explain the sensation of “tightness” in the chest.

Symptoms tend to get worse at night in asthma, says Butler, but other things can cause that too. It’s important to take the child to the GP if you have any concerns.

How is childhood asthma diagnosed?

There isn’t one simple diagnostic test for asthma so it’s a condition that is “fraught with misdiagnosis, particularly so in paediatric diagnosis”, he explains. That is why in the case of children, it’s recommended that a diagnosis is not made until the age of six onwards.

“The majority of wheeze-type conditions in the early years tend to disappear and are probably respiratory viruses rather than allergic asthma.” However, some children have very classic asthma symptoms triggered by allergies before the age of six, in which case a confident diagnosis can be made.

“The diagnosis requires the demonstration of excessive variability in breathing tests at different times.” When people who don’t have asthma are asked to blow as hard they can into a measuring device, the results will always be much the same. Whereas for people with asthma, affected by swelling in the lungs, the measurements will sometimes be much lower.

How is it treated?

For young children, medication to control symptoms is administered through an inhaler using a “spacer” device, which means the drug can be easily inhaled through a mask without them having to co-ordinate their breathing with the pressing of an inhaler. “They’re safe when we use the lowest effective dose. It is really important to have a written asthma action plan that will guide that treatment,” says Butler.

The use of such a plan has been effective in reducing the death rate, by getting diagnosis early and starting treatment early. It is also important, he says, that patients are warned about the overuse of short-acting reliever inhalers. “These are medications that don’t alter the swelling of asthma at all, they just widen the airways temporarily. They can give false reassurance to a patient who will feel better symptom-wise for a short period of time after taking these and they are also so much cheaper than other medications.

“This can start a vicious cycle of relying on the reliever medication and not using the preventer medication, which we would much rather happens.”

Using more than 12 reliver inhalers a year, ie one a month, “is a risk factor for death for asthma”, he warns. Inhaler technique is also a big issue, as it requires time and effort to learn to use one correctly. “Asthma only improves when the drug reaches its intended destination regularly, deep in the lungs, so inhaler technique is key to that happening.”

Are deaths preventable?

There are some cases where, no matter what, death will still happen, says Butler. However, the Asthma Society aims to reduce the number of deaths in Ireland by half by 2025, through education and awareness-raising at patient, practitioner and policy levels. Asthma deaths among all ages rose to 63 in 2016, from a 10-year low of 39 in 2012.  A review of six of 13 asthma paediatric deaths from 2006-2016 by Dr Des Cox, consultant in paediatric respiratory medicine in CHI at Crumlin, to be published in the Irish Medical Journal, found common factors among those deaths included: they were mostly adolescents, there was a sudden onset of the asthma attack; the patients did not have an Asthma Action Plan or it was out of date; they had not had structured reviews and none had seen a doctor recently.

For more information, see asthma.ie; or ring the free Asthma Adviceline 1800 44 54 64.

Asthma in Ireland by numbers

1 in 10 children currently has asthma.
1 in 5 children experiences asthma at some stage in their life.
5 – The average number of school days a child with asthma misses every year.
8,000 – The number of asthma admissions (child and adult) to hospital every year.
4 minutes – How often someone in Ireland visits an emergency department due to asthma.
Source: Asthma Society of Ireland

Read: It wasn’t ‘just asthma’

Sheila Wayman

Sheila Wayman

Sheila Wayman, a contributor to The Irish Times, writes about health, family and parenting