#84 Demystifying EoE with Dr. Christopher Parrish

In this episode, I’m joined by Dr. Christopher Parrish, a triple board-certified allergist and immunologist who leads Latitude Food Allergy Care’s Orange County clinic and has been involved in groundbreaking clinical research in both food allergy and EoE.

Dr. Parrish previously served as faculty at UT Southwestern Medical Center and helped lead a multidisciplinary program dedicated to eosinophilic gastrointestinal diseases. His work has contributed to clinical trials that ultimately led to the first FDA-approved therapies for food allergy and EoE.

In our conversation, Dr. Parrish explains:

• What EoE actually is
• Why it comes up so often in conversations about immunotherapy
• What families and patients often misunderstand about the condition
• How EoE is diagnosed and treated
• How patients and clinicians think through these risks when considering immunotherapy

This episode is designed to help patients, parents, and clinicians better understand the science and the decision-making around EoE and food allergy treatment.

Dr. Christopher Parrish, Latitude:
https://latitudefoodallergycare.com/about-us/team/clinical/christopher-parrish

From Fear to Freedom: A Workbook for Navigating Allergy Immunotherapy
https://a.co/d/003saZ8p

Special thanks to Kyle Dine for permission to use his song The Doghouse for the podcast theme!
www.kyledine.com

Find Dr. Whitehouse:
-thefoodallergypsychologist.com
-Instagram: @thefoodallergypsychologist
-Facebook: Dr. Amanda Whitehouse, Food Allergy Anxiety Psychologist
-welcome@dramandawhitehouse.com

Transcript

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Christopher Parrish, MD (2) 0:00

I definitely empathize with families who decide this food allergy can cause life-threatening reactions. EoE is not a life-threatening condition. It's a chronic condition. It has negative effects on quality of life, but it can be managed. We'll trade that for the possibility of these really severe anaphylactic reactions any day

Speaker 0:22

Welcome to the Don't Feed the Fear podcast, where we dive into the complex world of food allergy anxiety. I'm your host, Dr. Amanda Whitehouse, food allergy anxiety psychologist and food allergy mom. Whether you're dealing with allergies yourself or supporting someone who is, join us for an empathetic and informative journey toward food allergy calm and confidence. Today's guest is here to talk to us about one of the most anxiety provoking aspects of OIT for many of the families that I work with. And that's EoE. And if you don't know what those letters mean, stay tuned and he'll explain it better than I can. Dr. Christopher Parrish is triple board certified in allergy and clinical immunology, pediatrics, and internal medicine, and currently leads latitudes Orange County Clinic in Irvine, California, where he provides specialized care for food allergy patients of all ages. In the immunotherapy community, EoE is very often discussed and misunderstood. So I'm so excited to have an expert on the topic here, to talk to us about what families and patients actually need to know.

Amanda Whitehouse, PhD 1:21

Dr. Parrish, thank you so much for being here on the Don't Feed The Fear Podcast.

Christopher Parrish, MD 1:25

Yeah. Thank you for having me. I'm so excited to be here.

Amanda Whitehouse, PhD 1:28

I am really excited to hear both about you and about Latitude. Can you start by just giving us a little bit of background on your career and then on Latitude?

Christopher Parrish, MD 1:37

Yeah, so I did med school and undergrad both at University of Wisconsin. That's where I grew up. And then I moved out to Southern California way back in 2007, and I did internal medicine and pediatrics for residency at LA County USC. Then I did a year as a chief resident, a year as a hospitalist, and my fellowship all at LA County, USC. I spent a year in Long Beach after that, and then I decided that I wanted to get into academics. I transitioned to UT Southwestern and while I was there, my main focus was food allergy and EoE. So I would participated in numerous clinical trials for interventional therapies for food allergies, including peanut patch studies, Palforzia studies, the COFAR Outmatch study that led to the FDA approval of of Xolair for IgE emitted food allergy. And also the studies that led to the FDA approval of Dupixent for adolescents and children for EoE. While I was there, I also established a multidisciplinary EoE clinic together with my GI colleague, Dr. Goyle. We ran that clinic for the nine years that I was there. We treated hundreds of patients with EoE and then. Wanted to move back to Southern California and found out about Latitude food allergy care and how they were expanding to Southern California. So Latitude is a company that was founded in the Bay Area, San Francisco Bay area, by parents of food allergy children who wanted to bring evidence-based treatments to more kids. So. Historically, there haven't been a lot of treatment options for IgE mediated, food allergy, and they wanted to bring multi food, oral immunotherapy and Xolair and treatments like that to a wider audience. And this was an opportunity for me to continue working with food allergy, and to move back to Southern California where I wanted to be. So it was kind of a perfect confluence of timing and everything for me to be able to join, latitude. We opened our clinic here in Irvine in October.

Amanda Whitehouse, PhD 3:37

Great. You mentioned that you do OIT and combined with or separately Xolair as well. Is slit an option with latitude?

Christopher Parrish, MD (2) 3:45

We currently don't offer slit. It's something that we are talking about, and there's a lot of different options as far as kind of lower dose treatment options that'll probably be offered eventually through Latitude as well as at other places, with Slit being one of those at the peanut patch or epi cutaneous immunotherapy being another. And even just really low dose oral immunotherapy is something that has been gaining in popularity and growing evidence to support it over the years too.

Amanda Whitehouse, PhD 4:14

Right. It's so exciting to see those results coming out because I think the more options we have, especially low dose from the mental health side, it's reducing the fear and the resistance to the treatment, in addition to being very effective, it sounds like.

Christopher Parrish, MD (2) 4:26

Yeah, and it really allows for individualization kind of according to the goals and needs of each patient and family. There's a lot of variability as far as what every individual needs out of treatment, and I think that that's one of the great things. The more options we have, the better we'll be able to meet those needs.

Amanda Whitehouse, PhD 4:44

Definitely, within the food allergy community, I think there's those of us who know all about EoE and we're afraid we're gonna do something to trigger it in our kids. And then I think there are still people who aren't familiar with it and don't know what we're talking about. So can you give some background on exactly what EoE is and a little bit about treatments?

Christopher Parrish, MD (2) 5:01

Yeah, so EoE is eosinophilic esophagitis, which is why we often just call it EoE. It's a mouthful. When I describe it to parents, I often describe it as a lot like eczema, but happening on the inside. It is a chronic allergic type inflammation that's happening on the, the esophagus, which is basically the tube that brings your food from the back of your throat down to your stomach. The esophagus is not part of the GI tract where you typically should be absorbing food where the immune system should really be interacting with food. What predisposes to EoE we think is actually variations in the barrier function of the esophagus. The esophagus is supposed to form a barrier, kind of like your skin does. So similar to how in eczema, the skin barrier isn't fully functional, we think that in EoE that esophageal barrier isn't really functional and that allows for interaction between food triggers and the immune system to be occurring locally in the esophagus and triggering allergic type inflammation in individuals with a sort of a genetic predisposition.

Amanda Whitehouse, PhD 6:05

Can you talk about how strong that family component is

Christopher Parrish, MD (2) 6:07

yeah, it's not like cystic fibrosis or other diseases where there's just a single gene that if you have that gene, you're going to get it. It's much more like other allergic conditions like asthma or eczema, where allergic conditions in general tend to run in the family. There are some particular, gene variations that have been associated with EoE. But those aren't genes that are typically tested for outside of research settings, so we don't really know how high the risk is for any given individual. If you look at the risk among siblings, for example, it's only a few percent of siblings of someone with EoE who will also have EoE. But that is still much higher than the general risk in the population. Recent numbers are saying maybe it's as high as one in 700. So it's really not that rare, but that's still much lower than a few percent if you have a sibling with EoE.

Amanda Whitehouse, PhD 6:58

Oh, and do you think, is that more about identification and increased knowledge, or is it actually increasing as food allergies have increased as well?

Christopher Parrish, MD 7:05

I think it's both. All allergic conditions have increased over the years. We have a lot of environmental factors that combine with genetic factors to increase our risk of all types of allergic issues. With EoE in particular, it's something that requires an invasive procedure to diagnose. You have to get an endoscopy with a biopsy to diagnose it. So there's always that limiting factor, so there needs to be awareness of the condition, suspicion of the condition, and then the willingness to actually go through with a procedure in order to actually confirm the diagnosis. But if you look at the research, the rates of biopsies have increased over the years, but the rate of EoE diagnosis has increased at a higher rate. So it's not just that we're looking for it more.

Amanda Whitehouse, PhD 7:55

Okay. Within people who already have a food allergy, do we have an estimate of what percentage or how many of those people also will develop EoE?

Christopher Parrish, MD (2) 8:03

It, it's really tough to give an exact estimate, but it's definitely much higher. It's probably somewhere between 15 and 30% in some populations. It's really hard to to know what the true prevalence is because I don't think we're ever gonna do a study where every single individual with food allergy gets an endoscopy and biopsy regardless of whether they have symptoms. So,

Amanda Whitehouse, PhD 8:23

Not very practical or

Christopher Parrish, MD (2) 8:24

yeah. Yeah.

Amanda Whitehouse, PhD 8:25

you talk about for people who might have a concern, what would they be experiencing that might indicate that they would need it?

Christopher Parrish, MD (2) 8:31

Yeah, so the symptoms for EoE really vary by different age groups. So in adolescents and adults, the main symptom is dysphasia, which is a word that we use to basically describe trouble swallowing. And when we say trouble swallowing, what we're talking about is when chunky foods, especially dense meats like steak or pork chops or some types of chicken but also dense breads. Things like bagels kind of get stuck in the esophagus. So not at the back of the throat, but more in the chest really on the way down. Sometimes that can get stuck to the point where they have to just take a sip of water to wash it down. Sometimes they just pause eating for a little bit and it'll go down on its own. Sometimes it's bad enough that it gets stuck and they have to throw it back up. The bigger concern is sometimes even trying to throw it back up doesn't relieve the symptoms. And that's what we call food impaction, and that's a situation where the food is just stuck in the food pipe and it can be really uncomfortable, a really unpleasant experience. It can make it hard to just swallow your own saliva and it feels like you're choking. Even though it's in the food pipe, not the windpipe, it can still be really uncomfortable. It can be uncomfortable to breathe at the same time. And it, it's very anxiety inducing for patients who are experiencing it. In those situations, patients need to go to the er, they might need to get an an urgent or emergent endoscopy to go in and remove the food that's stuck. In younger kids, the, the symptoms are much more nonspecific. So they overlap with a lot of symptoms that almost every kid will have to some degree at some point in their life, makes it much harder to suspect it and diagnose it. It can be diagnosed as young as infancy. But in infants, toddlers, and young kids, the main symptoms often are vomiting, especially if it's kind of chronic vomiting that's happening, it can range from once a month or so to some kids throw up every day or multiple times a day. And the vomiting is often described as sort of random. So vomiting can also be a symptom of classic food allergy, where you eat a food and you throw up every time you have that food. The vomiting with EoE is often a little different. It's not necessarily directly correlated with when you eat that food. The foods that are triggering the EoE are in your diet on a chronic basis, but there's not that direct connection where I have that food and then I vomit immediately. It's much more random. So the parents often will even use the term random, like he just throws up randomly and I don't know what's causing it. It's a tough thing to diagnose it. Those symptoms can overlap with other things like just infantile reflux. Some kids just get car sick. They may throw up a lot for that reason and it doesn't have anything to do with EoE. Other signs or symptoms in those young kids can be feeding problems. So while they may not have food getting stuck in the esophagus, there's usually a lot of inflammation in the esophagus, so it can still be really uncomfortable to eat those same chunky foods. So infants are toddlers with feeding problems where they never get off of purees or liquids and they want to, they have a strong preference for soft foods. They're just eating purees and yogurt and formula or milk. That can be a warning sign, especially in a kid with other signs of allergies. So if they have bad eczema or wheezing or IgE food allergies, that should raise concern, especially if they've tried feeding therapy and they aren't making progress, that should raise concern. And all of this together can lead to, in some cases, difficulty gaining weight or even failure to thrive. And that's one of the bigger concerns with the younger children is that it can affect their growth and development. At young ages, good nutrition is really essential for, for normal growth and development. So it can be a very impactful thing for them.

Amanda Whitehouse, PhD 12:24

Yeah, it sounds so complicated and another yet, yet another one of our spectrum of allergy disorders. That is tricky because it overlaps both with the symptoms of the other ones and with a lot of just normal childhood stuff. One of those things I thought might be helpful for listeners to clarify because I think a lot of people are still just learning about FPIES too, which involves vomiting, but that presents quite differently than the vomiting in EoE typically, right?

Christopher Parrish, MD (2) 12:47

Yeah, so FPIES has two forms. There's chronic FPIES, which is almost exclusively in formula fed infants in the first few months of life. So typically this would be a baby on a milk based or a soy based formula who's just kind of chronically vomiting and with chronic diarrhea, there's often mucus, sometimes even blood in the stool along with it. And they'll almost always have failure to thrive and they can even get dehydrated. And when they come into the ER, they'll often get a workup for sepsis 'cause they'll look ill. They'll be really dehydrated. The more common presentation of FPIES is what we call an acute FPIES reaction. So if you take that same child and you recognize that the formula is the problem and you have them avoid it, and then a few months later, babysitter or somebody else is taking care of the child and offers them a, a milk-based formula. Then they'll have what we call an acute FPIES episode. And that is typically right around two hours after they eat the food. It's profuse, repetitive vomiting, almost exorcist style, projectile vomiting, to the point where they get often dehydrated. They'll often get pale and lethargic, especially the infants with this, they'll get pale and lethargic. They may have diarrhea hours after, and they might need to go to the ER and get IV fluids. This is also non IgE mediated, but so things like EpiPens don't work. The most effective treatment for FPIES is actually Zofran, which is just an anti-nausea med that's used for lots of other purposes as well. It's something that, if they avoid the food, they're not gonna have further episodes of it. Whereas with EoE, they're gonna have these more random episodes of vomiting. With FPIES, it's gonna be this trigger causes it. Now solid foods can often cause FPIES as well. So, some foods that are not really thought of as common food allergens are actually really common as triggers of FPIES. And examples of that would be things like rice and oats, more recently avocado has been really recognized. The triggers for FPIES do vary kind of geographically, but in general, whatever foods are being introduced really young. I have some risk of triggering FPIES. So in the Mediterranean, seafood is a more common trigger food for FPIES than in other areas. And as we've recommended earlier, peanut introduction to prevent IgE mediated food allergy, we're running into more and more cases of peanut triggering FPIES.

Amanda Whitehouse, PhD 15:11

Right, which gets so tricky, and I know that's not what we wanted to focus on today, but I am fascinated on learning more because then what do we do, right? We wanna prevent the food allergies, but we don't wanna cause cases of FPIES. So I guess there's probably a lot to learn with what's

Christopher Parrish, MD (2) 15:24

There, there is a lot to learn. My opinion is still, we should still still be trying to introduce the foods early if we run into FPIESs. Then we can deal with that by avoiding, most kids do outgrow FPIES over time. There are some cases where a food that triggered FPIES, then they go and avoid that food and delay its introduction into the diet. And then sometimes by the time you get around to introducing it, they've completely switched their allergy into an IgE food allergy. So it can get really tricky. So,

Amanda Whitehouse, PhD 15:50

Yeah. As we know, everything to do with allergies seems to be very tricky and complex. But,

Christopher Parrish, MD (2) 15:54

yeah.

Amanda Whitehouse, PhD 15:55

so before we start talking about immunotherapy and EoE, I was wondering if you could just give us an idea about treatments. You talked about being involved in the research on Dupixent. tell us what we do if a child or or an adult is diagnosed.

Christopher Parrish, MD (2) 16:08

Yeah, so for, for EoE there's different treatments that are available in adults. One thing that traditionally was done but doesn't treat the underlying inflammation is just dilating any narrowings of the esophagus. So we call that a stricture. If the esophagus has kind of scarred down to a point where it's really difficult for food to pass. When they're doing an endoscopy, they can place a balloon in and dilate that balloon and open it up. And that can relieve symptoms temporarily, but it doesn't fix the underlying problem, doesn't prevent the problem from returning afterwards. So that's kind of one thing that I would set aside that's not highly relevant for children because that typically takes years of the disease to progress untreated to get to that point. So when we're talking about treatment, then we're really talking about dietary therapy, which is essentially cutting foods out of the diet to treat the EoE by removing the triggers of it and medications. So let's talk about the medications first. So often considered the first line medication is the class of medications known as PPIs or proton pump inhibitors. These are antiacid medications that also do have an anti eosinophil effect. So an eosinophil is a type of white blood cell that's involved in allergic inflammation. And when with the diagnosis of EoE, the pathologist actually counts the number of eosinophils that they see in each section of the biopsy, and that's sort of what, confirms the diagnosis. They're not necessarily the main cell that's causing the inflammation, but they're a marker that that inflammation is there. And so the, that type of medication, it's an antacid medication. They're sold over the counter, so they're generally relatively safe medications, but they are used in higher doses for treatment of EoE than they are in the over the counter doses. And, you know, not everybody wants to be on a medication like that long term. There can be some side effects. There are some concerns about. Potential effects on bone density and things like that. So it, it's a medication that works in some cases. If you look at the research data, it's some probably around 30 or 40% of the time it works. And there are some patients where you try everything else and nothing works but that medication. It is something that is relatively inexpensive. So insurance companies in particular like to request that that's sort of tried before you move on to some of these other. The next treatment that has been used historically for EoE is what we call swallowed topical corticosteroids. So this is taking the same steroids that are typically inhaled for asthma or sprayed in the nose for nasal allergies or put on the skin for eczema, and we're trying to apply them on the surface of the esophagus. Our fingers aren't long enough to just rub a cream on the esophagus, so we have to get creative with how we get it there. The most common way traditionally has been what we call a budesonide slurry or oral viscous budesonide, or OVB. Some people will re will refer to it as. The first popular recipe for that was created by Seima Eva at UCSD in San Diego. And when I asked her how she came up with it, she said, oh, we just went in the break room and we started adding Splenda till it looked thick enough that it might coat the esophagus. And we tried it and it worked. So we published it. There's nothing magical about any of the recipes for those budesonides. You're basically just trying to take something that will thicken up the budesonide, which is just a liquid steroid medication that typically would be. Opened up and put into a nebulizer machine for asthma, but instead you mix it in a medicine cup with something to thicken it a little bit. We use applesauce, we use honey, we use maple syrup, pancake syrup, all that kind of stuff. Whatever the kid likes is a reasonable option to try and with the idea that when they swallow it, it'll kind of coat the esophagus and have an effect on the surface of the esophagus. After they swallow it, they aren't supposed to eat or drink for at least 30 minutes, ideally maybe an hour or so and with the idea that you have time for the medication to be in contact with the surface of the esophagus and have its effect, if they take a sip of water right after it's, it'll rinse it right off, sort of like rinsing shampoo outta your hair, so it won't have as much of an effect. In general, these are relatively safe medications as well. So many of these medications are sold over the counter. For example, the other version of swallowed steroids that we often use is Fluticasone, which is the generic name for brand names like Flovent and Flonase. Flonase is sold over the counter as a nasal spray. It's used in slightly higher doses for EoE and when Flovent was still made as a brand name, we use it a lot for EoE as an alternative way where you would puff it straight into the mouth instead of using a spacer. Have the patient just mix it with their saliva and swallow it. So the same idea as the budesonide slurry, just a different route of administering it. These medications work, depending on which study you look at, probably somewhere between 60 and 80 or or 85% of the time. And, they work as long as you take them. If you stop them, the, the problem tends to come back. There is now also an FDA approved version of it, of the budesonide that's Eohelia, and the issues with that are that the FDA only approved it for use for 12 weeks at a time. EoE is not a 12 week long problem. It's a chronic problem, so there's an issue with that. But it comes in pre-mixed packets, so it's kind of nice to not have to mix some sort of slurry every time you take a dose. It just comes in a little packet. You shake it up, it becomes more liquid when you shake it. And then once you swallow it, it kind of thickens up and coats the esophagus. So it's kind of like ketchup. The term they use is actually thixotropic for something that kind of becomes more solid when it's sitting still and becomes more runny when you shake it up. So that's another treatment option. And then the big gun is Dupixent, of course. So Dupixent is a biologic medication. It is given by injection. It works for almost any chronic allergic inflammation in the body. So it has many, many FDA approved indications, including eosinophilic asthma, atopic dermatitis. It's approved down as young as six months of age for that. EoE, it's approved down as young as one year of age. The problem with that is it's only approved for children who weigh 33 pounds and up or 15 kilograms and up, and there's not a lot of EoE kids at one year of age who have reached that weight yet. So realistically, it's probably more of the older toddlers who qualify for Dupixent, at least in the EoE dosing range, it is used at a slightly higher dose for EoE than it is for those other conditions. So for example, for eczema, it's typically a once a a month injection for the young kids. Whereas for EoE it's every two weeks for adults. It can be an every two week medication for other indications, but it's a once a week medication for EoE.

Amanda Whitehouse, PhD 23:04

Okay.

Christopher Parrish, MD (2) 23:05

and it works by blocking something that's called the IL-4 receptor alpha. So basically, it blocks two of the, the cytokines, which are sort of the chemical proteins that kind of drive this chronic allergic inflammation in the body. And they're known as IL-4 and IL 13. So by blocking two of those it works pretty well at kind of calming down that inflammation. So it's a really good option for patients who have multiple of these problems. A lot of patients with EoE also have eczema and or asthma, and so being able to treat multiple conditions with one medication can be pretty appealing.

Amanda Whitehouse, PhD 23:44

Yeah, and it's good to know that there are options, as you mentioned before, that being able to individualize that treatment and have lots of choices.

Christopher Parrish, MD (2) 23:50

Yeah.

Amanda Whitehouse, PhD 23:51

what I'm hearing is it's not necessarily a horrible, unmanageable thing if this arises, if you end up with EoE, obviously. And I think that's the, that's the impression that people have of EoE, so,

Christopher Parrish, MD (2) 24:03

Yeah. And, um, then as far as diet, the challenge with dietary treatment of EoE is. Because it is not driven by IgE antibodies, our allergy testing is really not helpful at all for figuring out which foods are causing EoE. So in order for a food to cause EoE, you have to be able to eat it on a chronic basis. So typically the foods that are triggers of EoE are foods that are in the diet in large amounts over a long period of time in order to cause that. Chronic inflammation. So it's not surprising that with the typical American diet, the most common trigger foods are milk and wheat, followed by things like egg, sometimes soy. So for doing an elimination diet, what's recommended is not doing allergy testing to try and figure it out. I think someday we probably will have good enough tests that accurately predict which foods are the hee trigger foods. But we're not there yet. It's an area of ongoing research. At this time what we do is, we call it empiric elimination, but it's honestly, it's guess and check. So we guess which foods are causing the inflammation. We eliminate those foods from the diet for an extended time period. So typically a minimum of eight weeks, but often three months or so. And then we repeat testing to see if the inflammation has gone away. So typically that's gonna be a repeat endoscopy with biopsy. We are now getting some less invasive ways that we can monitor the disease activity. So there is something known as the esophageal string test. It's also known as Entero Track, I believe is the, the name of it. And it's basically a pill with string inside and they, the child has to be able to swallow a pill. So you can't do this in really young kids. They have to swallow the pill and then tape the end of the string to the cheek. We will leave it in for about an hour, which can be pretty uncomfortable. A lot of kids with EoE one just swallowing pills in the first place isn't something that is really easy to do if their esophagus is inflamed and then they have to leave it in there, which can be a little uncomfortable sometimes. There's like kind of a gag reflex issue. But then they take it out, they cut off the portion that was in the esophagus and send it off to a lab and sort of get a thumbs up or thumbs down for the EoE is controlled or still active. There's also transnasal endoscopy which can be done without sedation. There's a lot of centers that are now doing this using virtual reality headsets to kind of distract the children and then go in through the nose without sedation and do the biopsies. This is typically gonna be older children and adolescents where this is offered to as well because they have to be able to kind of sit still through this. And some patients love it. Parents universally love it because they don't want their kids undergoing anesthesia. The kids, some of them hate having things in their nose or they hate it, triggers their gag reflex and they don't want ever wanna do it again. And other kids, it doesn't bother them at all. So the, there's other options out there for that. Now, getting back to the dietary approach though, so typically the old way of doing it was what we often refer to as the Six Food Elimination Diet, which I like to joke is called the Six Food Elimination Diet because the people who named it couldn't count to eight because it's milk, egg, wheat, soy, peanuts, tree nuts, fish and shellfish. So it's eight food groups. Even though we call it the Six Food Elimination Diet, but it's a ton of foods, some of which are not common trigger foods for EoE. For example, there's really hardly anybody, if anybody has had a shellfish triggered EoE, for example. So there's a lot of foods that are eliminated. It's really hard to follow. And, it works maybe about two thirds to three quarters of the time. Somewhere in that range, if you're able to follow it really strictly. In recent years we've really moved towards an alternative approach, which is essentially a step up approach where you eliminate one or two foods. So there have been recent studies that have shown that if you eliminate nothing but dairy products. That it's about 50% odds of controlling the EoE with that. That doesn't sound like that big of a deal. I'm from Wisconsin originally. It's a big deal. Cutting out all dairy products is not easy. We're not just talking about not drinking milk, we are talking about no ice cream, no cheese, no yogurt, no baked goods with milk as a, an ingredient, nothing with cow's milk protein in it at all. So it's still a pretty drastic diet, even just that, but it can be effective in about half of cases. And then if that doesn't work, then typically we would eliminate wheat or gluten. And then if that doesn't work, then step up from there to eliminating additional foods. Eliminate a food and the the inflammation is still present. You don't then swap that out for a different elimination. So you don't say, okay, milk, eliminating milk didn't work. We're gonna put milk back in and take weed out. That's not how you do it. You keep eliminating milk and you add to that elimination. You keep taking foods away until you get control of the EoE and then you can start adding the foods back in one at a time. And you either have an obvious return of the symptoms or you repeat the endoscopy and confirm whether the food is a safe food or a trigger food. It can be a really long process, but doing that step up approach, you tend to get to an answer faster 'cause most patients really have one or two trigger foods. So you can get to an answer faster with fewer endoscopies and biopsies than if you start off with a broader elimination from scratch.

Amanda Whitehouse, PhD 29:35

Yeah. Yeah. Certainly a daunting thing to think about taking on though as a parent. That's already hard enough to get our kids to eat anything. So,

Christopher Parrish, MD (2) 29:41

Yes. Yeah.

Amanda Whitehouse, PhD 29:43

But, so let's transition then into, we have that fear in the food allergy community that if we start OIT, trigger EoE, and then my child or I will have EoE for life. So let's start there with that question.

Christopher Parrish, MD (2) 29:55

Yeah. So EoE is a possible side effect of oral immunotherapy, or OIT. Basically, if you think about it, in order for a food to trigger EoE, it has to be in the diet on a chronic basis. Well, with OIT, that's exactly what we're doing. We're introducing the food on a chronic basis with very small amounts, and then increasing that amount over time. And you have to be able to tolerate the food enough to keep it in the diet in order to trigger that EoE. And that's exactly what the goal of OIT is to allow you to have that food in the diet enough to prevent those acute allergic reactions and in some cases, even to fully introduce it into the diet down the road. So that that can occur. The estimates for how common that is, it's hard to put a specific number to it. Our best estimates are probably somewhere around three to 5% of patients undergoing OIT develop EoE or symptoms that are probably EoE. And that's based off of, you know, all of the clinical trials of OIT and the reported cases of EoE within those studies. So it, it definitely can occur. Now the rates of GI symptoms during OIT are higher than that. So not everybody who has GI symptoms during OIT has EoE. The majority of patients who have stomach pain, or even some vomiting after starting OIT, many of them are able to back off on the dose, go slower and build the dose back up without the symptoms coming back and without developing EoE. So not everybody who has issues early on in OIT really has, EoE. Now there are some cases where EoE does develop. When that happens, I think that's a great example of when shared decision making really needs to, to take place. So, um, I think that at that time a discussion should be had, um, between the, the patient, the family, and the doctors of how to move forward. And there's a lot of options as far as that one option would be to. Back off on the dose and go to one, or go to one of these lower dose options like we were talking about before. So something like SLIT is a potential option. Sublingual immunotherapy. There are a few case reports of slit triggering EoE, but the, it's thought that it's much less likely to do so than OIT. So that, that would be an option. There's probably in the future gonna be even more options. For example, there's a peanut toothpaste that's in development that you might be able to switch to that if the peanut patch is on the market. It's not gonna be FDA indicated for use in that way, but it could be a way of doing sort of a low dose maintenance therapy. In fact, ViaSkin patch has undergone study as a potential treatment for EoE, the, the milk patch. There was a pilot study that was done at CHOP where it showed some promise for being able to treat EoE. So that may be an option down the road if and when it gets FDA approved, even if we have to use it off label in some patients as a an option. And there's also the option of just continuing with OIT, but treating the, the EoE with one of those medications that we talked about before. So I've definitely had cases where families came to me while I was running the EoE clinic in Dallas, and these were patients who were getting OIT done at other places and they developed EoE and they came to me and they said, we don't want to stop dosing the food. We don't wanna go back to fearing those accidental ingestions and those severe anaphylactic reactions. We wanna keep the food in the diet and we want you to treat the EoE. And we had good success doing that. So most of those cases we were able to treat with just the budesonide, just the swallow budesonide. We didn't even need Dupixent for most of those cases, but other cases we have used Dupixent as well. So there are definitely ways to treat around it, even if we think that the, the OIT has triggered the EoE. In general, a lot of people think, oh, if we have EoE we have to stop OIT. There's no way that you can move forward with OIT. And I think it's more nuanced than that. I think that it really depends on, what the family wants, what their goals are, and I definitely empathize with families who decide this food allergy can cause life-threatening reactions. EoE is not a life-threatening condition. It's a chronic condition. It has negative effects on quality of life, but it can be managed. We'll trade that for these, the possibility of these, really severe anaphylactic reactions any day, especially if it's a, a food that's as hard to avoid as as dairy.

Amanda Whitehouse, PhD 34:58

Uh, the way you are describing it is so helpful 'cause I think it completely flips how a lot of people who are managing food allergies already perceive this, even though they, they know that the food allergies obviously are anxiety provoking, but it's almost like they have the reverse of what you just described, where the EoE seems like the horrible thing if we were to trigger it. Which I've heard a lot of people say it's likely that it was underlying or that you would've developed it anyway. I mean, can you comment on that or is that hard to

Christopher Parrish, MD (2) 35:25

It's really hard to know. I think some of the hesitancy from doctors also comes from, you know, the Hippocratic oath. First do no harm, with the idea that if we're doing this treatment and we're causing another condition that maybe we shouldn't be doing that. And I would argue there are many, many documented cases, and I've had many patients who naturally outgrew IgE mediated allergies to foods, and then after that food was introduced to their diet, they developed EoE and the culprit turned out to be the food that they previously had in IgE mediated food allergy to. So I don't know so much that, that we're causing it. As you know, it's something that may have happened naturally otherwise in in a patient with that similar setup. As far as whether or not EoE is unmasking it, I think there probably are some cases where the patient had EoE and it hadn't been recognized. A lot of patients with EoE, they have a lot of symptoms when they're really young, with the vomiting and stuff. And then by the time they're teenagers or young adults, the disease has progressed and fibrosis or scar tissue has formed and they start having the trouble swallowing. But in the older children, kind of the second half of elementary school, a lot of those kids, they don't have a lot of symptoms with EoE. So sometimes it's sort of a, a silent thing there and, and you don't realize that it's there. So I do think there are probably some cases where it's unmasked, but there probably are other cases where it's truly triggered by the OIT as well. It's really hard to know that though, because we're not gonna be doing preemptive endoscopies and biopsies before treatment on every patient.

Amanda Whitehouse, PhD 37:05

Sure. Right. What's your take then on why this is so scary for the families who want to pursue OIT, but this is the main deterrent to them?

Christopher Parrish, MD (2) 37:15

So I think part of it comes from the fact that all of the clinical trials for OIT over the years have had EoE as an exclusion criteria. So we don't really have quality medical evidence saying what the risks and benefits are of doing OIT in a patient with a history of EoE, we've always excluded them from studies. So for a long time the, the most readily available option as far as getting access to OIT was through clinical trials. At some of the major academic centers, there weren't a lot of private practice docs offering OIT. And then patients with EoE would go there and ask about it and they'd be told, no, you can't. You have EoE. So I think that that kind of permeated the food allergy community as like, if you have EoE, you can't do OIT. I think it's a bit of a shame that that's kind of the perception, because as I, I mentioned, I really think it is much more nuanced than that. I think also the fact that they hear that EoE is something that is. Often, lifelong can be an issue as well. In all cases we think it's a chronic problem, and in most cases we think it's lifelong. I will say that there are some cases where EoE does resolve and doesn't seem to come back. There was a case series from CHOP that was published, quite a few years back where there were nine patients, who were treated with diet and then added all the foods back to their diet and the EoE did not return. Granted that was out of a. A chart review of 1800 patients. So it's less than 1% of the patients. But it does happen. And I had patients who I followed over the years who, we reintroduced all the foods gradually over time and weaned off all the medications and the EoE, did never come back. So it's not always a lifelong condition, and as mentioned before, it's something that's manageable. So even if it is a, a chronic condition, it's something that can be managed. Some patients need to be on a medication consistently or on a diet consistently. Other patients can be managed with episodic treatment. So, treat for a while, calm the inflammation down, give them a break from the treatment for a little while, and then go back on the treatment later on. An example of when we might do that, it would be a patient where the environmental allergies are playing a role as well. So some patients with really bad pollen allergy, their EoE will flare up seasonally. So we might use the steroids during that season for them. I think that there's a myriad ways that we can, can manage it. It's something that shouldn't drive as much fear as it does. I think the fact that it affects eating is another big factor. So, just like with food allergy, eating is just such a central part of being human,

Amanda Whitehouse, PhD 39:58

Mm-hmm.

Christopher Parrish, MD (2) 39:59

a person. It's social, for parents, one of the first thing you do to care for children is you feed them, so having a condition that makes that difficult or where providing what's supposed to be nurturing for your child, actually makes them uncomfortable or causes symptoms that can be, it can be really traumatizing and stressful. I absolutely understand it from that viewpoint as far as why it can stoke some fear, but I would just try and reassure everybody that you know that yes, it can do that, but we can work around that. We can manage.

Amanda Whitehouse, PhD 40:34

So what would you say to someone that is with an allergist who is wanting to stop or maybe doesn't have the experience with managing EoE and continuing forward.

Christopher Parrish, MD (2) 40:42

That's something that you know, at Latitude, food Allergy Care, we're really trying to be a place where people can come and get treatment regardless of what their particular circumstances are. I would advise, seek out a second opinion. Even maybe suggest that that allergist that you're working with, if there isn't, you know, a latitude in your area, ask that doctor to reach out to other, people with expertise. The allergy world and the food allergy world in particular is, it's a relatively small world. In general, we're pretty collegial. We're pretty nice people and we're always willing to help each other out. So if people have questions, you know, I've had a lot of doctors reach out to me over the years with questions about EoE and and food allergies. And I'm always happy to answer questions and, I would encourage people to keep asking questions and, and, and seek out second opinions. Don't necessarily take the first answer that you get as the only option

Amanda Whitehouse, PhD 41:35

Thank you. And that's helpful because when we're stressed and anxious about our kids' safety, then to work up the

Christopher Parrish, MD (2) 41:40

I,

Amanda Whitehouse, PhD 41:40

you know, have those uncomfortable, they feel sometimes uncomfortable for us as parents. Um,

Christopher Parrish, MD (2) 41:45

yeah.

Amanda Whitehouse, PhD 41:46

that I think will reassure people. It's not challenging your doctor, it's just asking questions and trying to get more information.

Christopher Parrish, MD (2) 41:52

Yeah. And, and as doctors we all have different backgrounds. We all have different things that we're more comfortable with or less comfortable with and, and that's okay. There's a lot of different ways to manage these. And there's nothing wrong with a doctor saying, I'm not comfortable doing OIT in a patient with your condition. What I'm saying is more so that, there probably are doctors that you could find who would be willing to do that, or places where that doctor could seek out advice that that may help convince them that they too could handle it. One thing I would add, if there's a preexisting diagnosis of EoE, we would want it controlled before we start OIT. So we don't wanna start OIT in somebody who has active EoE. We would wanna get the EoE controlled first and then start the OIT.

Amanda Whitehouse, PhD 42:44

Good, good distinction. Thank you. In general overall to parents who are feeling afraid of pursuing OIT, what would you say to them if they showed up in your office asking those questions and having that fear?

Christopher Parrish, MD (2) 42:55

Yeah, so, uh, what I would say is, yeah, OIT is one option for how to manage your food allergies. With everything that we do in medicine, there are trade-offs. There's risks and benefits, and you might weigh those risks and benefits different than the next family that comes in. And what I can do is kind of lay out those risks and benefits and give you my opinion as far as where your child likely falls as far as likelihood of running into some of those issues. But, 3% is not a high risk. 97% don't have that problem. I would always kind of point out the, the successes instead of al necessarily always focusing on the negative possibilities.

Amanda Whitehouse, PhD 43:41

Yeah. Thank you so much for that. This is incredibly helpful. So much good information and I'm so happy to have you on the show.

Christopher Parrish, MD (2) 43:46

Thank you. I really enjoyed it.

Speaker 2 43:49

As we wrap up today's episode, here are three next steps if you want to learn more or explore care options. First, if you are interested in learning more about immunotherapy or connecting with Dr. Parish's team or any of the latitude locations, you can find them at latitude food allergy care.com and on social media at Latitude Food Allergy Care. Latitude has locations all over California as well as a few in the New York City area, and they provide specialized care for patients of all ages. Second, if there isn't a latitude location near you, I encourage you to check out fast OIT.org, which is a nonprofit organization dedicated to education and access around oral immunotherapy. And third, if you're navigating decisions about immunotherapy or allergy treatment options and want more guidance about the emotional and practical aspects of the process. I wrote a workbook to support families through it called From Fear to Freedom. It's a guide to navigating allergy immunotherapy and. You can find it wherever you buy your books. I would encourage you to consider requesting it at your local bookstore, or shopping on bookshop.org to support local bookstores. I'll link it in the show notes. As always, everything else we discussed will be linked in the show notes too. I really hope that this season is helping you to think through some things and have a clearer picture of what might be right for you or your family. If there's someone else that you think it could be helpful for, please consider sharing, liking the episode, or leaving a rating or a review for the show so that more people can find it. Thanks for listening, and I'll talk to you again next week.

Speaker 4 45:14

the content of this podcast is for informational and educational purposes only, and is not a substitute for professional medical or mental health advice, diagnosis, or treatment. If you have any questions about your own medical experience or mental health needs, please consult a professional. I'm Dr. Amanda Whitehouse. Thanks for joining me. And until we chat again, remember don't feed the fear.