Childhood asthma overdiagnosed, argue leading respiratory doctors

In the past asthma was undoubtedly underdiagnosed, but the evidence now is that the pendulum has swung too far in the opposite direction, insist Professor Andrew Bush and Dr Louise Fleming of Imperial College and Royal Brompton & Harefield NHS Foundation Trust, in the journal.

It matters, not only because of the cost of inhalers, but also because of their side effects, which are more likely to occur in patients who are prescribed an inappropriate dose, they say.

"Inhaled corticosteroids, when properly used, dramatically improve quality of life and reduce the risk of asthma attacks and mortality," they write.

But there are potential side effects associated with their use, they point out. These include growth suppression and the dampening down of immune cell activity in the airways and the subsequent heightened risk of respiratory infections.

"There is also evidence that systemic absorption of [inhaled corticosteroids] depends not just on the prescribed dose, but is greater if the dose is inappropriately high for the degree of airway inflammation," they caution.

Key to diagnosing asthma correctly is a detailed knowledge of normal respiratory symptoms in healthy children, they say. But as the National Review of Asthma deaths shows, children who have asthma still die because of failures in basic management, including not taking inhalers that they really need.

"We propose that one contributing factor is that the diagnosis of asthma has been trivialised and inhalers dispensed for no good reason, and have become almost a fashion accessory," they write.

"The result is, the fact that asthma is a killing disease if not correctly managed, is overlooked," they say.

All too often, the hallmark symptom of asthma--wheeze--is used imprecisely by both parents and healthcare professionals. More objective evidence, such as simple breathing tests, is required before a diagnosis is made, they suggest.

"Is there any other chronic disease in the world in which children are committed to potentially hazardous, long term therapy without every effort being made objectively to document the diagnosis?" they ask.

They outline various approaches to aid correct diagnosis, including the need to remember that many children outgrow asthma symptoms, and that treatment shouldn't simply be stepped up if the child fails to respond, because there's a chance the diagnosis might not be right in the first place.