Gerald Lee, MD (Host): Hello everyone and welcome to another episode of Allergy Talk, a round of the latest in the field of allergy and immunology from the American College of Allergy, Asthma and Immunology. For today's episode, we'll be reviewing more articles from Allergy Watch, a bimonthly publication, which provides research summaries to college members from the major journals of allergy and immunology. And then we could also get CME credit.

Don't forget about that. It's education.acaai.org/allergytalk, as well as continue the conversation of these articles on the ACAAI community on Doc matter. Well, hello again. My name is Gerry Lee. I'm an Associate Professor of Allergy Immunology at Emory University. I'm an Assistant Editor of Allergy Watch, and today, once again, I'm joined by the editor-in-chief of Allergy Watch, Dr. Stan Fineman.

Stanley M. Fineman, M.D., M.B.A: Hello everybody, and it's great to be here. I'm also Adjunct Faculty at Emory, and I've been very active in the college. I'm a past president, so, I'm glad to be here and discuss the articles with you.

Gerald Lee, MD (Host): And for the third chair, we're again joined by Dr. Timothy Chow, an Assistant Professor at UT Southwestern and Assistant Editor of Allergy Watch. Tim, welcome back to Allergy Talk.

Timothy Chow, MD: Yeah, thanks. Time flies. It's been a few years now that I've gotten to be a part of Allergy Watch, and just really loved it and so thanks for having me.

Gerald Lee, MD (Host): Okay. Well, let's start with you Tim. I think you're bringing attention to a very important, issue regarding our pregnant patients with asthma. What have we learned?

Timothy Chow, MD: Yeah, so this article is titled Prenatal Indoor PM 2.5 Exposure is associated with worse maternal asthma health and lung function. So this was published in the Blue Journal, just this past February. And so as we're all you know, really aware of, asthma is common in pregnancy, it can often worsen during this period, and that leads to both poor outcomes for both moms and infants.

And, you know, there's been a lot of attention to outdoor air pollution and long been recognized as having harmful impacts on asthma, but people spend a lot of time also indoors and indoor air quality is far less regulated. And so the authors sought to investigate the effects of prenatal indoor PM 2.5 on maternal asthma.

So the way they did, they did this was it was a prospective longitudinal study of 19 pregnant individuals, with physician diagnosed asthma living in New York City. And so the researchers placed high resolution air quality monitors in participants' homes, for seven consecutive days in each trimester, and they measured PM 2.5 levels essentially every minute. During those same periods, the subjects were tracked with in terms of their daily asthma symptoms, they completed an asthma control test every four weeks and performed remote video guided spirometry to measure lung function. And so some of the results are essentially that there was a high exposure to kind of indoor air pollution.

So immediate indoor PM 2.5 levels were high, at 74 micrograms per cubic meter. Which doesn't mean much in of itself, but that's more than twice the EPA's 24 hour standard and eight times the annual standard. And higher indoor PM 2.5 exposure was significantly associated with worse asthma outcomes. So, they looked and found that a tenfold increase in PM 2.5 levels, it corresponded to a 3.3 point drop in the asthma control test.

And similarly proportion of symptom free days fell sharply from 80% down to 46% as well. Lung function was also affected, so there were reductions in FEV1, as well that were correlated with higher concentrations. And so this is really the first study to show that higher prenatal indoor PM 2.5 exposure is associated with worse asthma control, worse lung function in pregnant, women.

And while the study was small, and most of these patients were actually only on reliever only therapy. I think that these results draw attention to an important non-pharmaceutical management target of indoor air pollution during pregnancy.

Stanley M. Fineman, M.D., M.B.A: Tim, I don't recall, seeing an article that looked at the indoor air pollution. We've seen a lot about the outdoor air pollution. The higher risk for kids developing asthma, obviously the higher rate of exacerbations of asthma, but I don't know about this type of data with the PM 2.5, the small particle.

We do know about other allergens like dust mite or animals. Also smoke, we know is a big problem. But, I'm glad to see this, study came out and I think it's just another, talking point for us as allergists to tell our patients, what's going on inside the house because it's important.

Timothy Chow, MD: Yeah, and I think it's certainly, especially considering that, again, there's a lot less regulation of indoor kind of air quality. And so, just having kind of the message of patients to be aware of that and, as we start to explore like what are meaningful ways, for then individuals to assess their risk and then mitigate that I think is important.

Gerald Lee, MD (Host): Yeah, I was going to get to the mitigation and avoidance thing. So is this like incense? Is this like highway PM 2.5 going into the home? Is there any speculation on probably the major sources we could go after to help our patients?

Timothy Chow, MD: I think that's a great question. And it's probably, to be honest, not only all the above, but also very context specific as you mentioned. And so, I'm sure outdoor air quality does have an impact on indoors, especially if you don't have a really well ventilated home. In terms of, modifiable lifestyle things of, like you said, burning incense or burning candles or, having indoor kinda cigarette smoke exposure, and things like this. And so I think, again, likely there's very multifactorial components to this.

Gerald Lee, MD (Host): So Tim, I think that's a really important that we are addressing exposure instead of just treating folks with medicine, we're going to do a multi-faceted intervention to help all our asthma patients, and this article absolutely is a great reminder of that. So thanks for sharing this one.

I would like to break tradition on Allergy talk and mention a very interesting article identified by Vivian Hernandez Trujillo, and it's a review article and that's their tradition on breaking. I know we do a lot of research articles, but this one is particularly fascinating to me and this is entitled, Want to Help your Patients with Food Allergy Anxiety? Do Proximity Challenges? So this is talking about proximity challenges. So what is a proximity challenge, anyways? So a proximity challenge as defined by the article is a intervention where you are providing experiences of deliberate casual contact with a food allergen proven extremely unlikely to result in anaphylactic reaction.

So examples of this would be sniffing the allergen, having the allergen in a container closed or open near the individual or applying it on the skin, washing your hands afterwards, and then consuming food with hands that have been washed. These sort of mimic potential exposures that make our patients very concerned, especially those who are anxious about a life threatening reaction, but have been shown with great precautions to be safe exposures if in the right context. But as you know, food allergy anxiety extremely is disruptive to the quality of life of our patients. Examples can occur in sense of children who wish to eat at a separate table or be separated from other children because of risk of exposure.

This has been shown to hypothesized to increase the risk of bullying in the school as they're isolated or those who refuse to travel, or go to restaurants or not participate in activities. Social isolation can be a potential consequence of food allergy anxiety. And so a lot of proximity challenges is based in the theories regarding cognitive behavioral therapy, where although you are exposing someone to a stimulus that induces the anxiety, it is when you dispel, these incorrect beliefs about danger to self, that you create an extinction to the anxiety and potentially can assist a patient. And so some of the things that proximity challenges can do, is that again, it challenges and eliminates erroneous beliefs and overestimation of danger by showing that these exposures are safe.

It also can help patients practice experiencing the anxiety, and so when they experience that feeling, it helps them know how to manage with it even around their allergen. And finally, you're trying to build examples of skills for them to manage their food allergy in different situations. Because some of the goal of proximity challenges is that you do want to replicate authentic experiences someone may feel when, again, going to someone's house, going to a restaurant where someone may be consuming food that is your food allergy and trigger, but then you having the experience that this does not cause an allergic reaction. Now, the authors suggest some tools to help identify folks who might benefit from proximity challenges.

There are some questionnaires where you might ask, are you comfortable with having food allergens in your home? Can you eat next to someone who's consuming your food allergen, how many restaurants do you feel comfortable eating at or do you feel that you are able to do less activities than peers who have the same food allergen as you?

If someone says yes to these questions, then proximity challenges could help them alleviate some of the anxiety of casual, non-threatening exposure by first verifying that these experiences are safe in the safe office setting, but the authors want to take that one step further, that you create quote unquote homework where the individual would go and practice these same exposure skills in the real life setting, whether it's at the dinner table, in the restaurant, in a friend's house, or that sort of thing.

And then therefore, encouraging, rewarding, and supporting, that the patient is able to do behaviors that they were previously avoiding because they were able to overcome the anxiety that previously was their barrier. This article has so many pearls and tips, handouts, and suggestions that I do think it's worth a read.

You could obviously, go to the college website, or of course, this was published in the annals. I've definitely looked this up in the Annals, because it's just a really good toolkit that we really want to, again, support our patients, make sure they have the best quality of life possible, so their food allergy, doesn't interfere with that.

Timothy Chow, MD: Yeah, I think that's a great point, Gerry. That's something that we've certainly incorporated here at UT Southwestern. I think one of the interesting pieces, particularly when we were considering access to care is, especially for patients who are coming from far away and are really dealing with kind of severe anxiety and where perhaps some of these CBT concepts would require kind of multiple visits to help build on some of those principles that we've just had trouble finding kind of local, mental health professionals who feel comfortable enough around this area. And so I think not only do allergists need to, embrace incorporating this into their practice, but also building increased bridges, across with other mental health professionals to help facilitate this and alleviating that, I think will be really important as well.

Stanley M. Fineman, M.D., M.B.A: Yeah, I also wanted to have a shout out about, that was mentioned that. In this article about Dr. Dinakar. Chitra Dinakar was an allergist that unfortunately passed away too soon. And she was the one who really started talking about these proximity food challenges. So I just want to give this remembrance of her as one of the key pioneers to recognize that this is a problem and to suggest ways that we can help our patients get over this anxiety over the food allergy.

Gerald Lee, MD (Host): No, absolutely. I think, she was a giant in her field and I, appreciate that, Stan. I, think these are just these lasting contributions that really, help not only colleagues, but also, our patients. Ao I think we have one more article that Stan, you wanted to review, and it's raising a concern of a common asthma medicine we all use.

So, what should we be concerned about regarding tiotropium?

Stanley M. Fineman, M.D., M.B.A: Well, this article is entitled Tiotropium Initiation and Dementia Risk in Chronic Obstructive Pulmonary Disease. It was published in JAMA Internal Medicine in May of this year, May of 2025. And it was reviewed in Allergy Watch by, Dr. Josie. And the problem that was raised and what they're trying to study is the fact that tiotropium, of course, is a muscarinic antagonist.

And we're concerned about anticholinergics because especially in the elderly, there's a risk for cognitive dysfunction. This has been shown with oral antihistamines such as Benadryl. We now advise our patients who are over 65 not to use that, because of the potential for cognitive dysfunction.

And, since we're using these anticholinergics inhalation, is that could be a problem too. So this study was trying to answer that question. So, obviously COPD itself can be associated with an increased risk of dementia, but the fact that you're using an anticholinergic as well on top of it for treatment, that's the question.

Is there an increased risk of dementia in the older adults who have COPD when they're treated with the muscarinic antagonists, which are being used a lot with COPD. So, we know that the tiotropium has been compared, with a long-acting bronchodilator, and an inhaled steroid in the older patients.

And what this study did was they took a population based active comparator, new user cohort, and they used an administrative database from Ontario, Canada. So the cohort included new users of tiotropium, or a long-acting beta agonist in ICS in patients who were 66 or older who had COPD who did not have any dementia.

And they monitored this and they followed them and they looked at it over a year. And that's when they looked for the addition of the diagnosis of either dementia or the addition of a potential treatment, for dementia. So the way they define the onset of dementia was either a hospital admission with a dementia diagnosis or the addition of a cholinesterase inhibitor, which is of course, we know is used for treatment of potential dementia in two or more claims, over this lag period of a year after they, started having this baseline cohort or defined the baseline cohort. And the bottom line is it's very complicated, type study in terms of, looking at data. It was certainly looking at big data, but the bottom line was that they're using tiotropium monotherapy, there was a small increase in dementia risk for a thousand people on a rate of 29.6 versus 27.9 increase in rate of dementia in the group who had LABA plus ICS initiation. Okay. So the group, it's very minimal increased risk. They did some sub-analysis as well and I don't really want to go into that because it's a lot of statistical analysis.

But the bottom line was the fact that they felt that the benefit of treatment using an anticholinergic muscarinic receptor antagonist exceeds the risk for developing dementia in these patients. So, and that's one of the things that Dr. Josie said in his, comments, he felt that the difference it's unlikely to be clinically significant, especially when factoring in the clinical benefit of tiotropium that it provides for clinical symptoms. And so basically he felt that the clinicians, we clinicians should be reassured and reassure our patients when they use tiotropium, that it's not going to increase their risk for dementia.

Gerald Lee, MD (Host): You know, patients are definitely going to pick this up. Especially if, they are well-read about their side effects. I know a lot of my patients carefully ask about side effects. We do know long acting  muscarinic antagonists are considered first line for COPD. So I guess given the fact that a long-acting beta agonist is a reasonable option; I guess, would there be any downside of me just sticking to LABA monotherapy in our elderly COPDs, or is that going to be potentially less efficacious or maybe not the move, because I know that's not the first line for the guidelines.

Stanley M. Fineman, M.D., M.B.A: Well, that's what I was going to say. The guidelines obviously recommend muscarinic antagonist, so they're developed by people who know a lot more about this than I do, so I have to, defer to the guidelines. I dunno. Tim, what do you think?

Timothy Chow, MD: Yeah, the thing that kind of struck me was I feel like, that one year timeline is, sort of an interesting choice. Obviously, such a study of such scale, you already are working with such big data, in that period. But what it would seem to indicate to me is that adding, again, that anticholinergic effect, it might be unmasking what's already there.

But if you were looking at something perhaps longer, you would need a longer study period to really say, is this, having more of a downstream effect in terms of causation. And so that was just something that I was kind of considering in terms of just that duration of the study.

Gerald Lee, MD (Host): And it's a small effect. We do have to acknowledge, you're right. That was a pretty small effect. But I think again, when we get asked the question, I think, we can be very transparent about risks and benefits. We're sort of weighing the recommended first line therapy for COPD versus a very, very small, but non-zero risk to dementia.

And I think every one can individualize how they feel about that and as long as the patient is given the same information we are, I think they can make the best choice for health. So I think I appreciate you, Stan, for raising the attention for something I don't really think much about, but I do want to make sure our patients are well formed.

And so if you, did learn something as well, I really appreciate if you gave us some feedback, you could either put that in the comments or, email us feedback at allergytalk One word@acaai.org, our email address. Please again, rate us, on Spotify or Apple Podcast.

And of course, don't forget about CME credit. The website@education.acaai.org/allergytalk. And if you want to read any of the other articles reviewed on this issue to reach Allergy Watch, just go to college.acaai.org/publications/allergywatch. Well, this has been fun. I learned a lot. Thank you, Stan. Thank you, Tim, and thank you audience. We'll catch you on the next one. Have a wonderful day.

Disclaimer: The ACAAI is presenting this podcast for educational purposes only. It is not medical advice or intended to replace the judgment of a licensed physician. The college is not responsible for any claims related to the procedures, professionals, or products or methods discussed in the podcast. And it does not approve or endorse any products, professional services, or methods that might be referenced.