Asthma is being over-diagnosed and trivialised, say two leading specialists. And this is a major problem, because they say doling inhalers out like Smarties means that the small subset of people who have potentially life-threatening asthma may be missing out on the attention and care they need.

An Australian study of 108 children with a cough over three weeks, half of whom had been labelled as “asthmatic”, found that after extensive investigation only 5% did have asthma. Most had a bacterial infection that would probably have improved with antibiotics.

Commenting on their study, respiratory paediatricians Professor Andrew Bush and his co-author Dr Louise Fleming say that asthma was undoubtedly under-diagnosed in the past but question whether we have now gone “too far in the other direction”.

Not every coughing fit is a sign of asthma. In fact, although coughing is one of the symptoms of asthma, unless you also suffer from wheeze, chest-tightness or breathlessness, you probably haven’t got it. “I spend more time in clinic telling people their child doesn’t have asthma than confirming that they do,” says Bush.

But does it matter if you’re told you have asthma when you don’t? Yes, because you may just have a transient cough that doesn’t need treatment, and end up taking medication that costs money and can cause side-effects – and, crucially, there may be another cause of your symptoms that is being missed.

A diagnosis of asthma needs to be made with as much certainty as possible, because a failure to diagnose and manage it correctly can result in death. “The National Review of Asthma Deaths highlights another reason why we need to get the diagnosis right. It is an intensely depressing document that shows no lessons have been learnt over the last 15 years, and children still die because of failures in basic management,” write Bush and Fleming.

In the UK, about 5.4 million people currently receive treatment for asthma – 1.1 million of whom are children. The problem is that this figure includes many who don’t have it and misses others who do. “Asthma is difficult to diagnose because it’s episodic,” says Dr Samantha Walker of Asthma UK. “Wheezing illness in the under-fives is often labelled as asthma, when in fact it’s just a viral illness. They may be given inhalers that won’t do any harm, but then they must be re-evaluated.”

Treatment of suspected asthma is usually a blue inhaler (salbutamol, often marketed as Ventolin) to open up tight airways, and a brown steroid inhaler (inhaled corticosteroids, ICS) to prevent the inflammation that makes the airways narrow. So the brown inhaler is the preventer and the blue inhaler is the reliever. Walker says ICS are life-changing and remarkably safe but only work for about 50% of asthmatics.

Asthma is not only hard to diagnose, but affects people in very different ways. “It’s unacceptable that asthma still kills three people a day in the UK. We need to get better at stratifying the different kinds of refractory (hard to treat) asthma and identifying those most at risk. Until we know that, we’re scuppered,” says Walker.

At the moment, there’s a limited range of therapeutic options available and healthcare professionals follow Nice guidelines for treatment. New drugs such as biologics seem to offer hope for the 5% of asthmatics with severe refractory disease that doesn’t respond to standard treatment. But Walker says that people who don’t respond to ICS tend not to respond to biologics either. Much more research is needed to develop new approaches: the “one size fits all” options that we have at the moment are just not good enough.

But for most people, the drugs do work – if only they would take them. “We know that kids who get hay fever, and whose asthma is triggered by pollen, can drop grades in their GCSEs. They need to be taking their ICS regularly to damp down the irritability of their airways,” says Walker.

The figure of 1,200 asthma deaths a year in the UK has hardly changed for years, and preventable factors are identified in 90% of cases. Not smoking, starting ICS promptly, avoiding triggers including anti-inflammatory drugs, and knowing how, why and when to use medication are all key. Everyone with a diagnosis of asthma should have written guidance in the form of a personal asthma action plan and an annual review if symptoms are persisting or worsening.

It would obviously be preferable to avoid asthma altogether if possible. But asthma is a combination of genetic susceptibility, which you can’t do anything about, and triggers, such as pollen, dust, viruses and moulds, that are hard to avoid.

Breathing exercises can complement standard medical therapy and improve patient-reported outcomes and mental wellbeing. Asthma UK has found that nearly one in 10 people with asthma use unproven therapies such as homeopathy, acupuncture, ionisers and Chinese herbal medicine.

Bush also has the following advice for parents of children who are too young to manage their own asthma. “If parents see their kid is breathless, wheezy, coughing at night or needing their Ventolin inhaler two to three times a week, they need to go back to the GP. If necessary, they should get a second opinion. Pitch your expectations high. The kid shouldn’t be needing to use a blue inhaler often. They shouldn’t be ending up in hospital.”