Dr Gerry Lee (Host): Food allergy is a complex, potentially life-threatening condition that requires a multidisciplinary approach, yet confusion persists in disti distinguishing IgE and non IgE. Immediate reactions from intolerances at the same time, advances in immunotherapies. Biologics are opening new opportunities for proactive personalized care. Hello everyone. My name is Jerry Lee. I'm an associate professor at Emory University and the host of this three-part miniseries entitled Food Allergy Frontlines Clarifying Diagnosis.

Advancing treatment from the American College of Allergy, asthma and Immunology, and is supported by a grant from Genentech. In this episode, We'll discuss how to accurately diagnose and manage food allergies in primary care covering testing indications, referral criteria. Prevention strategies and risk stratification, and I'm excited to be joined by two food allergy experts in the field.

Our first expert is Dr. Brian Vickery. Dr. Vickery is a professor of pediatrics and chief of the Division of Allergy and Immunology at Emmy University and Children's Healthcare of Atlanta. A nationally recognized clinician scientist. His research focuses on improving outcomes for children with food allergies through novel interventions and therapies.

He has authored over 125 publications and is a leading voice in advancing the field of pediatric food algae. Brian, welcome to the podcast.

Dr Brian Vickery: Thanks, Jerry. Happy to be here.

Dr Gerry Lee (Host): And our second expert is Dr. Edwin Kim. Dr. Edwin Kim is an associate professor of pediatrics and chief of the Vision of Pediatric Allergy and Immunology at the University of North Carolina School of Medicine. He also directs the UNC Food Allergy Initiative Research Group, whose focus is the development of novel therapeutics for food allergy.

Welcome to the podcast, Edwin.

Dr Edwin Kim: Thanks for having me, Jerry.

Dr Gerry Lee (Host): Okay, let's get started. Brian, let's start with you. Food allergies are a common condition in the primary care office. It's affecting approximately 8% of children and 11% of adults in the United States. However, we know that the diagnosis of food allergy isn't very clear cut. It's often challenging and confusing to patients, caregivers, generalists, and.

P, honest US two for allergists. So in your practice, how do you approach the diagnosis of a food allergy?

Dr Brian Vickery: Jerry, this is a great question. The most important aspect of making a food allergy diagnosis is taking a good history, and that's why my new patient visits often will take a long time. Now, sometimes the history is totally obvious. Let's say a young child who tries a single food, say scrambled eggs for the first time and within a few minutes, has a clear allergic reaction involving unequivocal objective symptoms like hives or anaphylaxis.

And that's witnessed by the parent who's providing this history and. requires urgent treatment, taking the child to the emergency department where the care was documented. In a case like that, the diagnosis of egg allergy is so obvious that a first year medical student could make the diagnosis even really without a lot of testing, but in other cases, it's not so clear.

So, for example, certainly we know that increasing awareness of food allergies may lead many families to seek evaluation and testing before they've even attempted the food. And they wanna know, is my child allergic to this food before we even try it? And in that case, there's not even a history to take, and sometimes other cases, the food's ingested, but then what happened next is not clear.

So take that egg allergy case, as an example. Let's say that child reacted to egg and it's clear that they're allergic to egg. Now it's time to try peanut. and the parent who's kind of traumatized from the first reaction offers a little fingertip size amount of, peanut butter, and the child sort of spits it out.

Maybe, you know, scratches a little bit, complains and just won't take any more of that. So now they're nervous. Well, does that represent a peanut allergy? Even though there clear, aren't clear signs of an allergic reaction to peanut at that point. And then yet, another common scenario is those, more high risk patients that we worry about.

With say, moderate to severe atopic dermatitis, who are at higher risk of developing food allergy than patients without, atopic dermatitis. And patients like this may have vague, non-specific symptoms like scratching or runny nose or loose stool. days that they might try a new food. And so something objective did happen that was witnessed and it had some relationship to eating, but it's not clear that it was an immune response to the food.

And so these, different kinds of scenarios can be challenging. It's important to know all of these details which really form what we consider the pretest probability of disease. You know, and this is a concept we talk about with our residents and fellows in the clinic. Understanding what that pretest probability is then helps us interpret any test we order afterwards.

So this is a, common clinical reasoning process that really applies to any test you're gonna order, inside or outside of allergy. When I talk to families though, what I tell them, ultimately the most important test is the swallow test. what happens when you eat the food? What are the circumstances?

What is the outcome? Because everything we do to diagnose patients depends on the answer to that question.

Dr Gerry Lee (Host): Yeah. Thanks Brian. I mean, You're sort of mentioning that many of the times the patient comes in describing a reaction and not many of them are slam dunk, and so it sort of makes sense if we're worried about IG immediate food allergy, we're just gonna test for ig. We're gonna do a blood test, we're going to do a skin test, and that's gonna clarify the diagnosis.

Edwin, could you talk about skin testing and allergen specific IG in terms of its accuracy and helping us make the diagnosis of food allergy?

Dr Edwin Kim: So, I mean, many of us, patients, providers. All of us really, we automatically think about a test when we're thinking about making a diagnosis. I mean, I, think a good example of this, would be the rapid strep test, or even more recently, where you have these home COVID tests.

We do the test, A line pops up, it means, positive, and if there's no line, then it means that it's, negative and you don't have the flu, or you don't have COVID or you don't have strep. When it comes to food allergy, though, the problem is there is no yes, no test available at the moment that, we can use.

And so it actually often surprises our patients who are expecting that. But just like Brian just explained, the diagnosis really comes almost entirely from the history. It's the reason that we ask. So many questions when the patients come into the clinic, even though in their minds the diagnosis is sort of already there.

but, you know, we really wanna know, is it a food that is commonly known to cause allergies? are they symptoms that typically fit for allergy? what was the timing? Did it happen sort of shortly after eating all of these pieces? Exactly, like Brian just mentioned, really go into this concept of pretest probability.

Once we have that good sense of, yeah, this. sounds pretty good for allergy. That's when we go into the testing that you mentioned, the skin testing and the blood testing. And here, really what we're looking for is just trying to show that that patient actually has the IG antibody, to the food that we can now connect the dots between the symptoms that they've had, and the actual immune system itself.

I think one thing that's important for patients to realize is that the skin tests and the blood tests are actually trying to show us the same thing. There are two different ways of doing it, but both of them, are trying to show us that the patient actually has IgE specific to that food in their immune system.

The part about the testing though, that makes it tricky and why it's so important that we get the history and have a good sense of whether there's allergy or not. First, is that we also know that you can have IgE, but actually not be allergic. and the likely reason for that is there's probably other aspects of the other parts of the immune.

Them that are basically protecting against the allergy, kind of combating that. and so, that swallow test that Brian mentioned is essential here. So, if you eat the food every day and don't get sick, it doesn't matter what any kind of test tells you, it doesn't matter that you have a positive ig.

You've clearly shown that you are not allergic. On the other hand, though, it makes sense if you don't have IgE, how in the world could you have an allergic reaction? And so that gives us a pretty good sense that, you are likely not allergic and there's a different explanation for the results or for the symptoms that they're having.

Dr Gerry Lee (Host): So, I think Brian and Edwin, you're sort of making the case here that unfortunately. It's not clear cut for us just to make the diagnosis of food allergy through just allergy testing. I think referrals to the allergist can integrate the pretest probability and the test to make sure we're avoiding over or under diagnosis.

But at least when the primary care clinician sees a patient with a history of food allergy, is there some steps that clinician should take before referring to the allergist, since that might take a while.

Dr Brian Vickery: again, it gets back to. What that history is and how convincing it is. Something that's convincing to me might not be convincing to someone else and vice versa. so it's a little bit subjective, but for the purposes today in, discussing with the kind of the more primary care audience, let's say someone has a clear, obvious initial presentation of anaphylaxis.

So, has an exposure to peanut hives, vomiting, coughing, you Almost like a shock-like presentation ends up in the emergency department, gets epinephrine. Clear history of, peanut allergy. the emergency department should, provide that patient with a prescription for auto-injectable or intranasal epinephrine if they don't have it already. and that patient should be coached on how to use it, although that doesn't always happen, in an emergency department setting.

and then in addition, they need, things like a, written allergy action plan and some, and maybe some supporting documentation, if the child's in school and so on. Just to manage the condition. And given that we know that access to allergists can be somewhat problematic, widely, and especially in certain places, it's important that the primary care clinician is connected to that patient who's had a reaction.

To make sure that the patient and family know what to do in case of an emergency while they're waiting to see the allergist. And so there may need to be a visit to go through, okay, do you have this epinephrine device? Did you actually get it from the pharmacy?

Was it prescribed? Is it the right dose? Do you know how to use it? Do you know when to use it? Under what circumstances you might need to treat a reaction and what to do next? So that the family has a little bit of a lifeline while they're trying to wait for the allergy appointment.

And, you know, I really would just encourage to sort of leave it at that and resist the temptation to start the workup. it's really easy and, families often understandably wanna know what's going on. but sometimes a well-intentioned attempt to try to make the diagnosis ends up with, Unnecessary testing that can be confusing and actually potentially even cause harm to the patient if it leads to dietary restrictions, especially early in life.

So really, I, I would recommend kind of leaving the workup to the allergist and not ordering testing, and really focus the short term approach on ensuring that the patient and family understand what anaphylaxis is, how to treat it, and go from there.

Dr Gerry Lee (Host): Brian, I wanna go back to your previous point about a convincing history of food algae. I mean, you mentioned sort of this immediate anaphylaxis present. You're all familiar with, but I think there are some presentations that I'd love for you to give advice about regarding the primary care to address, except Ally, the most common question we hear from caregivers is food algae evaluations to evaluate food triggers for eczema or atopic dermatitis.

What would be your advice for our primary care clinicians to address that question?

Dr Brian Vickery: we spend a lot of time on that in the clinic, because I think there's a lot of misunderstanding or misinformation about the. Two conditions. and so really my approach starts with an education about what eczema is and what it's not. and while eczema is strongly associated with food allergy, it is not caused by food allergy.

and that's an important point to get clear on. May sometimes be considered a little counterintuitive or difficult to understand from people. And it seems a little. Basic to say eczema is a skin condition, but it is, we know that there are strong genetic determinants, for what causes eczema, and those are genes that, control skin barrier function.

they're not actually immune system genes. so there's evidence that this is inherited. It often runs in families and so I often, say to folks when did the eczema start? Often it's early in life and we know that it, runs in families and has genetic origins. And I'll say, this is kind of the skin that they were born with.

and it's understandable to think, well, what is it in the environment that's causing the skin to be so inflamed all the time and so itchy and so difficult to control? is it something they're eating? Well, important to ground that conversation and this is the skin that they were sort of born with.

and there's, two main components to eczema. That all patients battle to one degree or another, and it's different for different patients, and that is dryness and sensitivity, right? We know the dryness comes from the skin barrier dysfunction, and that's largely genetically controlled. the skin gets dehydrated very easily. It has hard time.

Holding onto water. Water evaporates at very high rates from the skin that leads to dryness. The dryness leads to itching. The itching leads to scratching. The scratching leads to inflammation. It's a sort of vicious cycle. And then all patients, to one degree or another have a lot of sensitivity that is to anything with a fragrance to heat to.

Bug spray, sunscreen, bacteria on the skin, stress, the type of fabric that's right up against the skin. all these things can make eczema worse. and for some patients, foods might be on that list, but actually there's some literature that suggests that the rate of food triggers is much, much lower than people actually suspect.

It's usually a combination of all these other factors. and it's especially hard to tell what foods might be doing. When the skin is outta control, if you're flaring all the time because the skin's not under control, then it seems like every time we're eating something later that day, we're having trouble.

Well, it's important to get the skin under control to really understand what, the diet's doing. And we find that a lot of patients are not prescribed appropriate potency, topical steroid medicines and other, effective treatments. They're not using enough. Emollient, the skin is not under good enough control. It's interesting.

There's also literature that suggests that the concern that parents have about food triggers goes dramatically down on follow-up visits when the skin, is better controlled, right? So families come, they wanna talk about foods. I pivot the conversation and talk about skin first order of business is let's get the skin under control.

If we can do that and then see them again, in follow up and the skin is, not cured, but cleared and, the child's doing better and everybody's sleeping better and, more comfortable, then actually the conversation about what food is it, goes down quite a bit. and again, there have been studies that have shown this.

So really, to recap, it's a conversation about what eczema is, what it's not, what drives it, what doesn't drive it. and again, we really want to resist the temptation to test these kids for a whole bunch of food triggers. because they may well be sensitized to foods, like Edwin said, they may make IgE to foods that are just what we would call false positives.

They're, not relevant. and when you start looking. you find things that are distracting and actually potentially counterproductive or harmful, so we really wanna focus on getting the skin under control and leaving the diet alone.

Dr Gerry Lee (Host): That's excellent advice. Thanks for summarizing that. So obviously primary care clinicians are on the front line for addressing these questions about atopic dermatitis, eczema, but also we have now rec. Recognize that primary care plays a huge role in food allergy prevention. Edwin, are you able to summarize the advice generalists should be giving parents about prevention of food, algae, especially if they have an infant or expecting a newborn.

Dr Edwin Kim: Absolutely. I mean, for years we really thought that kind of waiting was a good thing, waiting for our gi tract, waiting for our immune system to actually be more mature, before introducing foods like milk, egg, and peanut, thinking that that might sort of allow us. To prevent the allergy as well as the kids to be able to more verbalize if there is a problem.

unfortunately though, over that time we saw the opposite. So instead, we actually saw the rates of allergy continue to go up and up. And right now one of the estimates we often speak of is that one in 13 kids, two kids in every US classroom might have an allergy to some kind of food.

And so, to me it's clear that sort of waiting has not worked. so this advice actually officially got turned on its head in 2015 with the publication of the leaps. Study the learning early about peanut study and this study, was really important because it showed that the opposite was true.

The sooner you can get peanut into the diet, in the case of this study getting, kids between four and 11 months of age to eat the food, the peanut. The greater chance you actually had to prevent a peanut allergy. And the general idea that I think of is that the GI tract, it's designed to tolerate foods.

I mean, everything that we eat is foreign to our body. And thankfully we're not allergic to everything. So it's made to actually tolerate the food. And so if we can first get exposed to the food by eating, our immune system is more likely to develop tolerance to it. On the other hand though, if we get exposed to the food by some other root through the skin, exactly like Brian was talking about with your eczema, atopic dermatitis, or even possibly by breathing it, our immune system may actually overreact to it, see it as something bad.

And maybe that's what allows for the allergy to happen. And so really thinking about from the, general pediatrician, I think the major advice that I would. Recommend is that there is really no benefit to waiting to introduce the foods at this point. And if anything, waiting keeps the door open for someone to become allergic.

And so really the sooner the kids can eat peanut as well as these other common food allergens, I think the greater chance they have to tolerate the food and to prevent the allergy.

Dr Gerry Lee (Host): Yeah, I think after the learning early peanut study, we are all doing our best to try to advise caregivers on introducing, allergenic foods early to their diet. Obviously, there may be some concerns from the caregiver, for primary care clinicians. What resources or handouts or other techniques can they use to educate caregivers on how to do early introduction of food?

Edwin, what do you advise?

Dr Edwin Kim: this is the hard part I think. So it's easy for us to say, okay, get the food into there and you'll be better. and some families get right into it so there are actually a lot of sort of commercial products. You could easily just get some peanut butter diluted, some of these puff snacks that were used in the study as well.

So there are different things that are available and some families will jump right in there. There are going to be other families that are just rightfully nervous, whether they know that they have allergy already in the family or just. kind of aware, and cautious about that. And that's a place where I think, a partnership between the general pediatrician and the allergist can be super helpful as well.

whether it's sort of coaching along the way or even observed if necessary, just to sort of help, develop that sort of courage and the confidence to be able to continue to do this. it is an area that I, think. Many different places are giving many different types of advice when it comes to sort of how to introduce it or how to rightfully introduce it.

I think right now the major thing that I, focus on with my patients is less about the actual type of food, as long as it's not a choking hazard, but more about this sort of frequency and keeping it up. I think it's so, so, so important that you gotta keep it in the diet multiple times a week and for an extended period of time.

the danger that I'm seeing right now is that patients. hear the message. They start it. They do it a few times, then they get busy. And then suddenly, it's been a week and then suddenly it's been two or three or four weeks since they've last given it. And what I worry about is, again, does that keep the door open for that, patient to become allergic.

And so, you know, I know the Quad AI and the American College of Allergy, both, have great resources that are available out there. and there are many more that are, I think, are being developed that will help to give the, Best practices on how to do it, but again, just as important as making sure that they can keep that up, for an extended period of time to really maximize the chance of preventing the allergy.

Dr Gerry Lee (Host): Yeah, thanks, ed. We'll, provide links that y'all can click on in the show notes, associated with this podcast, but again, I appreciate the conversation This. Concludes part one of our three part series, food Algae. Front Lines, clarifying Diagnosis, advancing Treatment. Next, we'll cover FDA approved and emerging immunotherapies like oral sublingual and epi cutaneous immunotherapy, as well as the expanding role.

Of biologics like omalizumab in managing complex food allergies. if you enjoyed this and want to hear other interesting episodes from Allergy Talk, please visit college.ac ai.org/allergy talk. And again, my name is Jerry Lee. I'm from the American College of Alga Asthma Immunology. Thank you, Brian. Thank you Edwin. And y'all have a wonderful day.