Melanie Cole, MS (Host): Welcome to AHN MedTalks, an informative resource for physicians across various specialties as we delve into the latest medical insights and best practices ensuring you stay at the forefront of your field. I'm Melanie Cole and today we're highlighting food allergies with Dr. Russell Traister. He's a Pediatric Allergy Immunology Specialist at AHN Pediatric Institute.

Dr. Traister, thank you so much for being with us today. Before we get into this topic, give us a brief overview of your role at AHN, your experience and your expertise in this field.

Russell Traister, MD: Sure. Well, I've been at AHN a little over three years now, and I work in the pediatric department as one of the allergy immunology specialists. And so we just see little bit of everything, but it's funny, I am in the pediatric department, but I see kids and adults. So, we see both over here, even though I'm in the pediatric department. So that's one nice thing as well.

Host: Well thank you for that. So define food allergy for us and differentiate, if you would, between food intolerance and other gastrointestinal conditions that mimic food allergy symptoms because there are so many and we're learning so much more about the immune system and its relation to the gut and its relation to allergies and it's all tying together. Give us a little differentiation of how those things go together and how they're different.

Russell Traister, MD: Sure, and that's a really important question for an allergist, too, because, and for primary care doctors, because a food allergy for an allergist is something very, very specific. And when we're talking about food allergy, we're usually talking about what's called IgE mediated food allergy. And that IgE is just the allergy antibody.

And so what we mean by IgE mediated allergy is you're having reactions due to an IgE antibody in someone's body that is reacting to certain foods and substances. And the reactions that you have when you have IgE mediated food allergy are very specific, and it's usually something called anaphylaxis, which is a severe allergic reaction.

And that includes things like hives, swelling, trouble breathing and wheezing, you can have nausea, vomiting, diarrhea, and also you can pass out and have shock from a food allergy. And that's what the real definition of an IgE mediated food allergy is, and that's important to differentiate from other symptoms you can have with foods.

Obviously, that's a very serious condition to have anaphylaxis to certain foods, but you can also have you mentioned food intolerances. And food intolerances can be quite annoying, but at least they're not life-threatening as anaphylaxis is. So a common food intolerance that people have would be something like lactose intolerance, where often as people get older, they lose an enzyme called lactase in their gut and they can't process lactose appropriately, and that gives them a lot of gastrointestinal symptoms.

Nothing bad is going to happen, but really if it's quite bothersome, the real treatment is really got to avoid things containing lactose or take some of those products called like Lactaid that help you break down some lactose if you have any in your diet. That can help minimize your symptoms.

That's one type of food intolerance and then I think the other thing that gets confused with food allergy a lot that I see is something called irritable bowel syndrome where a lot of times people will complain that almost any time after they eat they have a lot of gastrointestinal symptoms shortly thereafter, often diarrhea, and that can be thought of as maybe being a food allergy, and it's actually not.

It's really not a sensitivity to anything in particular. What's happening, I tell people, is that the problem that they're having is not related to a specific food. It's more related to an internal problem in their gut. And so the type of testing I have for food allergies is not very helpful in those circumstances, just cause that's not the same type of reaction that you're having when you're having something like that anaphylaxis or true IGE mediated food allergy.

Host: Dr. Traister, as we're talking about pediatric allergies, but certainly adults come up with some adult-onset food allergies to seafood. And you've mentioned the difference between intolerance, but many adults are going to go see their primary care. And so as you're speaking to other providers, what would you like them to be on the lookout for, for an adult-onset allergy that they didn't have for most of their life?

Russell Traister, MD: Sure. I will say adult-onset food allergy is pretty rare except for seafood. So fish and shellfish, you can become allergic to at any time in your life. And I wish I had a reason for why, we don't really know. But I've had many a patient who, you know, in their 40s, they eat seafood all the time, and boom, all of a sudden, they come in with having hives and swelling or wheezing after they're eating shellfish, and sure enough, their testing is positive.

But apart from that, it is actually quite rare to have other IgE mediated food allergies arise. It's not impossible. I've seen it a handful of times, but again, it's usually pretty clear cut because the symptoms are that hives and swelling and real anaphylactic type symptoms. And so, if it's not fish or shellfish as an adult, and they're complaining about food symptoms and they're not having those anaphylactic type symptoms, then I would think of something else.

Host: That's great advice. Now on to pediatric food allergies. When we think of pediatric food allergies, and we've heard over the years, and pediatricians let their patients know very early on what to stay away from as we begin new feeding for newborns, but I'd like you to speak about that. The most common food allergies in children that you see, but also why some of that has changed in how we look at those because it used to be stay away from this, that, but now we're not quite doing the same thing. So speak about pediatric food allergies and what's going on in your field today.

Russell Traister, MD: Sure, the most common food allergies in kids are going to be milk and egg and nuts. Those are the most common. We list wheat and soy on there as well. Those can be common allergens, though see those less frequently than the other ones I mentioned. So that's important. But that's a good point you made about how allergists talk to patients about when to introduce some of these foods because when I was training, we used to tell people to avoid peanuts, for example, until age 4 because we thought that if we did that, we could prevent peanut allergy.

And several years ago now, some studies have come out that show that actually that was not appropriate and probably we increased peanut allergy by doing that because the studies had shown that especially in kids with eczema, that introducing peanut protein early and that's starting around four to six months when you're just starting to introduce foods, that if you introduce peanut at that time, it can be way to potentially prevent peanut allergy in children.

And the one caveat to that is that I think an early introduction is probably important. I know the studies were with eczema, but it probably is appropriate, and everyone and it's not going to hurt anything to introduce it early, but if someone has moderate to severe eczema, they should see an allergist first because we usually want to test those patients ahead of time before we introduce peanut protein because there's a lot higher likelihood they might be allergic, so we'll test those kids first.

But, that's the biggest difference that's happened in the last several years is just that early introduction of peanut. They're doing studies for other allergens like milk and egg, and, it's probably similar, we just don't have all the studies yet, but introducing those things early is probably better as well, those particular proteins.

Host: How do you diagnose them? What's changed in your field in the last 20 years or so? Tell us about some of the various testing methods and diagnostic criteria.

Russell Traister, MD: Well a lot of the testing hasn't changed a ton over the last several years. We test by either skin test or blood test for allergies. Both of them are really a measure of your IgE. One is we can measure your IgE to specific foods directly in the blood, but the skin test is more of an indirect measure of IgE.

The skin test is thought to be a little bit more sensitive, and what I mean by that is sometimes in kids that are allergic or have eczema, they have sort of a background level of IgE, and you get a lot of low level positives in the blood that sometimes we don't know quite what to make of, it's just a number, you know, and so the skin test can be a little more sensitive sometimes if you have a low level positive on a blood test, that might turn out to be negative on a skin test so that's one of the reasons we might do a skin test instead of a blood test.

Host: Once you determine what's going on, Dr. Traister, and I mentioned it a little bit before, the desensitization therapies. Speak about some of the treatments that are out there and some of the oral food challenges because certainly children with certain allergies are at high risk for anaphylaxis, as you said, certainly in the school systems when it's a wheat allergy or peanuts. So speak about the therapies that are available now today that have kind of changed the game for you.

Russell Traister, MD: Well I'll say one of the things that is upcoming and we're still doing lots of studies on is something called oral immunotherapy that's to some of these foods. And unfortunately there's only one FDA approved oral immunotherapy and that's for peanut and they've actually recently expanded the indication for that down to age one where you can give that to patients with potentially the peanut allergy.

I will say that there are lots of allergists in private practice and whatnot that can sometimes come up with their own oral immunotherapy formulations for different types of foods. And there are studies ongoing with those, but as I said, they're not FDA approved. I actually don't do a lot of oral immunotherapy in my practice, and one of the reasons is because I have found that taking the oral immunotherapy, which involves taking a little bit of this protein every day, for example, with peanut, it's a peanut powder, and you're increasing doses to certain doses, and the whole goal of it is not to be a cure for peanut allergy.

It's only meant to hopefully minimize your reaction should you accidentally ingest peanut, for example, at school or something. So it's in no means a cure. The problem is, is that number one, you have to take this every single day and number two, it's not without its own side effects. As you can imagine, you're giving someone peanut powder who's allergic to peanut, but you can have some allergic reactions just to the specific testing.

And so I've not found it to be something I include in my practice. If patients are really pushing for that, sometimes I have some allergists in the community that do some of their own stuff that they can explore that further, but I just warn them again that a lot of it is not FDA approved.

Host: How do you counsel your patients about emergency management of anaphylaxis should it occur?

Russell Traister, MD: So every patient that I have that has food allergy usually walks out of my office with what's called a Food Allergy Action Plan, and that is just a sheet of paper that describes if you're a child or you're an adult having a reaction to a specific food that you're allergic to, what approaches to take.

If your symptoms are limited to just locally on the skin and a small area of a hive or something, you can take some Benadryl or a Zyrtec, but if it's anything more and you're starting to have symptoms spread either all over, hives all over, or any of those other systems like trouble breathing or gastrointestinal symptoms or feeling lightheaded, then that'd be an indication for the EpiPen and every patient with a food allergy should have an EpiPen.

We go over proper use of that as well.

Host: Tell us about the new FDA approved nasal epinephrine and compare the advantages and disadvantages to injectable because, you know, we've always thought of the injectable and patients are very concerned about the cost of these as well. Tell us a little bit about this new FDA approved nasal.

Russell Traister, MD: They recently approved this nasal epinephrine spray called Neffy, N-E-F-F-Y, and it is an alternative to injectable epinephrine, and it's just the studies have shown it's equally as good at treating anaphylactic reactions, that's why it was FDA approved. And so I think for some patients, this is going to be beneficial.

I found one of the reasons is because sometimes I find that patients are reluctant to use the EpiPen because they don't want to inject themselves with a needle, which some people are pretty fearful of that. And if you have patients that, that's their reason for not wanting to administer epinephrine, then I think that the nasal epinephrine spray would probably be a good alternative for them. Regardless if you use an epinephrine, you should go to the emergency room afterwards. So sometimes that's a deterrent for people they don't want to go to the emergency room after. But obviously the difference between the nasal spray and the injectable form is not gonna prevent that.

But I do have a few patients that were like, I would use this now if I needed it because it's available in a nasal spray and not an injection.

Host: Well, thank you for that. And before we wrap up, can you just briefly touch on a rare food allergy, Alpha-Gal syndrome? Tell us just a little bit about that and its unique features compared to other food allergies.

Russell Traister, MD: The Alpha-Gal syndrome is in the last 15 or so years, a new food allergy that has sort of developed that's related to tick bites. And what happens is when some people that are bitten by ticks become sensitized to a carbohydrate or a sugary type molecule called Alpha-Gal that's on mammalian meat.

And what happens is subsequent to that bite by a tick and sensitization to that, people, when they ingest any type of mammalian meat, have an odd form of food allergy that results in delayed anaphylaxis. What I mean by that is instead of more immediate reaction where traditional IgE food allergy, like to a peanut for example, people have reactions within minutes to a couple hours at most, this delayed anaphylaxis is happening six to eight hours after ingestion.

So a lot of people are waking up in the middle of the night with anaphylactic symptoms and it was sort of a mystery and through a lot of good studies it was determined that it was due to sensitization to this particular molecule Alpha-Gal due to these tick bites. So that's just a rare food allergy that it's rare but it occurs and I've seen it here in Western Pennsylvania. So it's something to look out for as well.

Host: What great information you've given us today. Do you have any final thoughts, things you would like other providers to consider before referring to an allergist or when you feel it's important that primary care refer to an allergist?

Russell Traister, MD: I think if any time a person comes in complaining of any allergic related conditions, we're happy to give some advice on that. I think taking some of these things into consideration, especially regarding the food allergies, because I know primary care doctors get a lot of patients concerned for food allergies, and I'm hoping that even this podcast today will help clarify some of that.

So it'll help them be able to relay some of this information to their patients. But, we also see things like asthma, environmental allergies, chronic hives, those type of conditions. So we're happy to see them if people want to send them to us.

Host: Thank you so much, Dr. Traister, for joining us today. And to learn more or to refer your patient, please call 844-MD REFER, or you can visit ahn.org. Thank you so much for listening to this edition of AHN MedTalks with the Allegheny Health Network. I'm Melanie Cole. Thanks so much for joining us today.