Asthma: Over- or underdiagnosed?

“Asthma is probably overdiagnosed by a factor of 5,” said Michael Seear, MD, pediatrician, respirologist, and instructor with the University of British Columbia Certificate in International Development, Vancouver, during a Monday presentation.

Miles Weinberger, MD, professor of pediatrics at the University of Iowa Children’s Hospital, Iowa City, counters that although asthma is at times overdiagnosed, it is also at times underdiagnosed.

In the session titled “A contrarian view of asthma: Is asthma being overdiagnosed?” the two experts agreed that the problem stems from the lack of a clear definition for asthma.

“You don’t have epidemics of broken legs or leukemia because there is a firm diagnosis for those things,” explained Seear.

“There is a fixed definition for someone having a heart attack or diabetes. You can measure those things, but there’s nothing similar to that for asthma. It’s a clinical diagnosis,” lamented Weinberger.

Seear continued, “Children today are healthier-bigger, stronger-than they’ve ever been. The default position should really be that they are healthy,” but the default position is often that they’ve got allergies, asthma, or some other condition. “Pretty soon you take completely healthy little kids and you’ve got them on treatment,” he said.

Weinberger countered that if patients and their families looked back to when symptoms actually started and not when a diagnosis was received, the most common age for asthma to start would be in the first year of life. He said that 85% of all asthmatics had their onset in their first 5 years.

He explained that preschool-aged children have the highest hospitalization rate for asthma, reporting that 5% to 10% of all hospitalizations for US children are for asthma, and that the asthmatic aged younger than 5 years has twice the number of hospitalizations as school-aged asthmatics and 5 times the number as teenaged asthmatics.

“There are other studies that suggest that patients are being overdiagnosed with pneumonia, and very often when you look at those studies, probably a lot of what’s called pneumonia in young kids is actually manifestations of asthma,” said Weinberger.

He concluded, “Someone once said, ‘Maybe asthma is like love; there is no definition; you can’t define it, but you know it when you see it.’”