Considerations for Diagnosing Patients With Asthma

This is part of the MD Magazine^® Peer Exchange, “Precision Medicine in the Treatment of Severe Asthma.”Click here for Segment 7 and learn about strategies for treating patients with asthma.

Peter Salgo, MD: Let’s pull back. Let’s talk about clinical medicine again. I think there’s going to be an intersection, as we go forward, between all of this science and the clinical treatment of asthmatics. You’re working up somebody with suspected asthma. First, just clinically, what are the important questions that you ask someone? What’s the interview like?

Raffi Tachdjian, MD: Certainly, the history is going to be quite important. In most of our specialty allergy and immunology, a lot of it is based on the history. Exacerbations, the upbringing, and the location within the country where they’re living are also important considerations. In my particular area, Los Angeles, pollution is huge. We’ve got smaller particles that fly under the radar. Nonetheless, those are ultra-fine particles.

Peter Salgo, MD: They’re active.

Raffi Tachdjian, MD: They cause inflammation, which is the root of what we’re talking about here.

Peter Salgo, MD: What about in the office?

Raffi Tachdjian, MD: Then you could look at response to therapy—what has worked and what has not worked. We seem to still abide by the mantra that steroids work for everybody when, in fact, we talk about neutrophilic asthma versus eosinophilic asthma. Even within the eosinophilic phenotype, there are certain subtypes, based on their polymorphisms, that may not respond. In fact, they may do worse with a corticosteroid.

David Rosenstreich, MD: May I jump in here?

Raffi Tachdjian, MD: Yes.

David Rosenstreich, MD: In terms of questions, we focus on the patient’s environment. You don’t want to overlook that. If a patient is sleeping with their cat, no matter what you give them, they’re never going to get better unless they stop doing that. If they have mold in their bedroom, which most people don’t even bother asking about, or sometimes people aren’t even aware of it…

You want to know where they’re living and what they are they being exposed to. And if anything that they’re being exposed to is asthmagenic, you want to try to eradicate, it if you can.

Peter Salgo, MD: Everybody is talking about FEV1 [forced expiratory volume in one second] as if this is something that’s easy to do in the primary care physician’s office. Is it? Do they do it right? Can they interpret it?

Neal Jain, MD: I think spirometry is a challenge unless it’s in the hands of people who know what they’re doing.

Peter Salgo, MD: Does that mean we should throw it away? You don’t know how to do it?

Neal Jain, MD: I don’t know if it means that we should throw it away. It can be very helpful. The guidelines suggest that we should be measuring it at least once a year and at the time of the initial onset. And we should be measuring bronchodilator reversibility.

Peter Salgo, MD: By using the FEV1? You can do that in the office if you do it right?

Neal Jain, MD: You can do it in the office. It takes training and teaching your patients how to do the maneuvers properly.

David Rosenstreich, MD: I was trained in an area where they had developed peak flow meters. I don’t know how other people feel about that. I find them to be very, very useful. Everyone can measure a peak flow. Patients can measure it themselves. I find it to be very, very valuable and easier to perform than a full FEV1.

Raffi Tachdjian, MD: Part of the problem with these machines, or contraptions, is their variability. You might get normal responses, especially at 8 AM when everyone’s cortisol is at their highest. You should really have them come back at 10 PM or 2 AM to catch the culprit.

Peter Salgo, MD: Which brings up another question. Is it common to underdiagnose asthma? Is it common to overdiagnose asthma?

Neal Jain, MD: I would say that both are common. Going back to spirometry, we did studies when I was a fellow-in-training. This was a long time ago—15 years. At a tertiary care center, in severe asthmatic children, at the National Jewish hospital, 80%-plus of our severe asthmatics had normal lung function in a situation where we were doing the maneuvers properly. It can be easy to underdiagnose and underevaluate individuals because they may not have obstruction or reversibility.

Overdiagnosis is equally common. There are a couple of studies, done by our Canadian colleagues, that were published in the Journal of the American Medical Association in 2016. Results demonstrated that 30% of people who were diagnosed with asthma, when objectively assessed, didn’t have asthma.

Peter Salgo, MD: Oh, this is a giant morass. We’ve got to do better than this.

Neal Jain, MD: Absolutely.

David Rosenstreich, MD: The problem is that in most cases, among primary care doctors or patients, asthma is underdiagnosed. People don’t perceive that this chronic cough that they have is asthma. Sometimes the FEV1 is normal. If you don’t look for bronchodilator reversibility, you’re going to miss significant airway inflammation. We said both are common. We find that the underdiagnosis is the problem. People go untreated.

Peter Salgo, MD: OK.

Transcript edited for clarity.