Comorbidities and Worsening Symptoms in Asthma

This is part of the MD Magazine^® Peer Exchange, “Precision Medicine in the Treatment of Severe Asthma.”Click here for Segment 11 and learn about the rationale for step-up therapy in asthma.

Peter Salgo, MD: What are the other comorbid factors if it isn’t high disease? Or even with high disease, what are comorbid things that you’re looking for?

David Rosenstreich, MD: Well, obesity is one of them.

Peter Salgo, MD: Why?

David Rosenstreich, MD: In part because of mechanics of airway abuse but also because obesity generates a lot of excessive inflammation that may contribute to asthma as well. And then there’s a big unknown. We don’t know why, for sure. It seems to be generating noneosinophilic inflammation. Other comorbidities are linked to the environment. You have to pay attention to age, as people get older, previous smoking history, and things like that.

Neal Jain, MD: Chronic sinus disease.

Peter Salgo, MD: Chronic sinus disease.

Neal Jain, MD: Acid reflux.

Peter Salgo, MD: I was going to ask about acid reflux. Nobody brought that up. To me, that’s fairly new on the scene.

Neal Jain, MD: It’s a debatable subject. Is it a distinct entity? Is it part of asthma? Is it something that contributes to asthma? I think that when you talk to different people, they’ll have their own slant on it. Often, we don’t like to agree, but I think it is something that we consider, especially when people have uncontrolled disease—is there another condition, like reflux-driven airway disease?

Peter Salgo, MD: All the time, I hear, “What’s the harm in giving an H₂ blocker?”

David Rosenstreich, MD: Well, there is a harm.

Peter Salgo, MD: There’s harm in anything.

David Rosenstreich, MD: The PPIs [proton pump inhibitors] increase one’s risk for pneumonia and food allergies. It’s not harmless. But I think the point about chronic sinusitis is very important. Nasal polyps are problems that really contribute to the inability to control asthma. By themselves, they can be addressed.

Raffi Tachdjian, MD: Just one more thing. History is very important. When we look at Th2-high asthma, this is the skewing that’s based on being born with parasites in our system.

Peter Salgo, MD: Do you want to run that one by me again?

Raffi Tachdjian, MD: Traditionally, we had worms and all kinds of parasites. These Th2-skewed mechanisms that were born would help defeat these.

Peter Salgo, MD: OK.

Raffi Tachdjian, MD: And because we don’t have that, thanks to the hygiene hypothesis and a cleaner environment, now we have skewing where our immune system wants to have a pleasant exercise, not a fight. Therefore, it starts picking away at other proteins that are out there, such as allergens, viruses, and so on.

Peter Salgo, MD: Let me back this up and enter the realm of pop culture, just for a moment, based on this assumption. Several years ago, the assumption was, “Keep my kids away from all these allergens. They’re going to be happy. They’re going to eat peanut butter and be fine.” Then we heard, “Let them eat dirt because that’s the way their immune system learns to distinguish bad from good.”

Raffi Tachdjian, MD: That’s what’s happening in Northern and Western Europe, in some of these studies looking at LPS in the environment from cow manure and from having dogs and large animals around. If a child is brought up in that environment, even if you pluck them away and put them into an inner-city area with a cleaner or more hygienic environment plus or minus pollution, they actually retain some of that protective factor.

Peter Salgo, MD: So they do better?

Raffi Tachdjian, MD: Exactly.

Transcript edited for clarity.