Uncovering the Truth About Food Allergies - Diagnosis Journey (Part 1)

Welcome to Episode 25 of The Immune Edit Podcast, hosted by Dr. Doug Jones. In this special three-part series on food allergies, Dr. Jones is joined by expert allergists Dr. Farrah Khan and Dr. Tom Chaco. Part 1 explores the patient's journey from initial reactions to accurate diagnosis, addressing common misconceptions like hidden food allergies, when to test, and the pitfalls of invalid testing methods. Tune in for expert insights on IgE testing, IgG myths, and more to help families navigate food allergy concerns effectively.

Meet the Experts: Introductions from Dr. Doug Jones, Dr. Farrah Khan, and Dr. Tom Chaco

Dr. Doug Jones: Hi everyone. This is Doug Jones here with my fellow colleagues. Do you want to introduce yourselves? Dr. Khan and Dr. Chaco?

Dr. Farrah Khan: That's Dr. Khan to you, Dr. Jones. Respect my elders—not my elders, but even my youngers. Y'all are my elders. I'm so excited to be here and chat with you guys. Look at Tom's face—I called him an elder. I wanna ask how old you are, but I'm pretty sure I'm not allowed to.

Dr. Tom Chaco: This is gonna be a good conversation. We're already off track.

Dr. Farrah Khan: I am an allergist, mostly seeing pediatric patients in Columbus, Ohio, in the academic setting.

Dr. Tom Chaco: And I am Tom Chaco. I am also an allergist in the Atlanta area, seeing peds and adults, seeing everything.

Dr. Doug Jones: Awesome. Today we're gonna have a three-part series on everything food allergies. Many of you have probably seen the three of us put some segments together. We've taken collections of questions from previous sections that we weren't able to answer and put them into a three-part series.

Part one is through the patient's journey from that reaction all the way through diagnosis, with some pertinent questions. Part two is transitioning into treatment options. The third part is parents and families—how are we dealing with that emotional load that goes with food allergies? So it'll be three sections, three segments.

What Are Hidden Food Allergies and Why Do They Irritate Experts?

Dr. Doug Jones: I'm gonna start with a question to you two. It's something that irritates me. There are a lot of things that irritate me, but one thing that really irritates me is when I get on social media and see influencers talk about hidden food allergies. The reason it irritates me is it leads to an onslaught of patients coming in looking for their hidden food allergies, or they have a huge spectrum of symptoms and want large panels of tests.

So the first question with that lead-in is: when do you guys test for food allergy? When somebody has a symptom, when is it appropriate to test and what is appropriate to test?

When Is It Appropriate to Test for Food Allergies?

Dr. Farrah Khan: You want me to give the diplomatic answer, then Tom's gonna come in? The history guides everything. A good allergist is gonna take the time, even if just a few minutes, to parse through and figure out where symptoms are coming from.

Food allergy reactions are not hidden. It's not like you're living with a peanut allergy and don't know it—you know it. Anytime you've been exposed to a peanut butter cookie or sandwich, food allergy reactions are not subtle.

This week, I had four or five patients where parents asked, "How do we know nasal congestion isn't a hidden food allergy?" It's time to stop scrolling a little bit, guys.

Dr. Tom Chaco: I agree—it's not subtle. You should know it. I should look at you and say, "What's up? You look like the Nutty Professor." Show me a picture of swelling or hives. If it's fatigue or something, you may have food intolerance or sensitivity—that's different. For food allergy, what our tests tell about, it's not subtle. You know it.

Why Do Influencers Promote Hidden Food Allergies?

Dr. Doug Jones: So what's really happening with those influencers? Why do they put that out there?

Dr. Farrah Khan and Dr. Tom Chaco: Money. Money, money, money.

Dr. Farrah Khan: It's money. They take advantage of patients with symptoms that need addressing. Our healthcare system isn't set up to address them thoroughly. People walk out of 10-15 minute PCP or allergy appointments feeling nothing got addressed, still dealing with symptoms. So they turn online for health information. Not everyone can figure out what's credible. Wellness influencers fill that vacuum.

Dr. Doug Jones: Where are they making money on this?

Dr. Farrah Khan: Supplements, workshops, tests. IgG tests, home test kits, saliva tests, invalidated tests they're selling. Hair testing—send a sample of your hair and I'll tell you what you're allergic to.

Dr. Tom Chaco: I just got two today with IgG testing panels. I already know they're gonna be mad at my response because they spent a lot of money. I pretend to look at it, but they're mad if you don't give credibility. They spent $200-500. The validity isn't the greatest—I sugarcoat because I don't want to insult. But we know it's not helpful. Real evidence shows it doesn't correlate with symptoms.

Dr. Doug Jones: Why do those tests continue to exist?

Dr. Farrah Khan: Money, money, money. People are making hundreds and thousands off this—it's not a small market.

Dr. Doug Jones: Why don't people sue these companies marketing food sensitivity tests?

Dr. Tom Chaco: I don't know. Legally, you can't say they're wrong—you say it's not evidence-based. People swear by it. We're not giving legal advice.

Dr. Farrah Khan: Food sensitivity tests claim they'll tell you intolerances—that's unequivocally false. They detect immune response against food, but don't tell you that response doesn't mean bad—it may mean tolerance. IgG is what we track as good. We use it to say you tolerate peanuts or milk—IgG goes up. Studies show IgG is good, tracked. It's telling your immune system is working.

That underscores the misinformation. People are desperate with real symptoms: bloating, stomach pains, intolerances. They're sold the one thing that sells, scales, but often fails. The test someone believes in—they scale it because not under license, sellers aren't real doctors, or scale to cash model—no medical necessity proof like real medicine.

It fails because not the answer. Selling misinformation, hope to desperate patients who feel bad and want answers. They say, "Tell me what to avoid and I'll avoid it. Do the whole panel." We take nuanced, complicated answer: symptoms valid, but allergy door isn't right.

It's like the dating game with mystery doors: door one misinformation, door two legitimate testing.

What Are Validated Tests for Food Allergies?

Dr. Doug Jones: Behind door number two: legitimate tests like skin testing and blood tests. Comment briefly on why validated, when order, limitations.

I want to comment on money with IgG. We run a busy allergy practice in Atlanta. 3-4-5 years ago, Groupon called: do IgG testing, charge $400, you get $200, we get $200. I was confused. If test on Groupon, that's a problem.

Dr. Tom Chaco: IgG testing isn't the way.

What Do IgE Tests Really Tell Us About Food Allergies?

Dr. Doug Jones: What is the testing good for? IgE testing, food-specific IgE—looking at allergy antibody. Skin test and lab tests measure same, different ways. Good for classic allergic reaction: gave kid peanut, lips swelled, hives, vomiting, ER, EpiPen. That's all it tells. Limitations including false positives.

Dr. Tom Chaco: False positives, especially blood work in eczema patient with high IgE—super high to everything. Don't do screening testing—child has this, do blood work in eczema, everything positive. Harm: positive test, avoid food during introduction window. False negatives maybe, but more false positives 50-80%. Careful—history plus testing gives diagnosis. Numbers in context of person and history.

How Do Allergists Use Food Allergy Tests in Practice?

Dr. Doug Jones: How do you utilize these tests in practice? Validated tests—what looking for, limitations. How utilizing?

Dr. Farrah Khan: Trend over time—helpful, not skin test but lab test. Baseline marker, repeat every 6 months if younger baby, 6-9 months or every year. See overall trend. Depends on allergist and office. Good allergist looks beyond numbers.

Recently had patient with egg white almost 100. Doing great on egg ladder—not huge fans, but worked for family. Came in for unbaked egg challenge, ate entire scrambled egg no issues with level almost 100. Crazy—if hadn't paid attention to tolerating, never challenged, kept egg allergic. Trending helpful, not hard rule.

Dr. Doug Jones: IgE to egg over 100, history meh, challenged fine?

Dr. Farrah Khan: Hives with initial scrambled egg under 1 year, maybe 9 months. Avoided bit, then baked egg challenge. Other adverse reactions, eczema. By time back to egg, working egg ladder at home. Passed baked, then up ladder less heated. Repeated labs—on pancakes/waffles months, still almost 100 egg white. Total IgE dropped bit—think ready. Parents ready—came in, did great.

Dr. Tom Chaco: Going out to world: excellent. Most allergists wouldn't challenge—okay. Benefit good food allergy institution higher risk challenges. Advantage you have. I do lots challenges, nervous 2-year-old IgE 80-90 egg scrambled. Public know not every allergist same, capabilities same. Awesome you did—cleared egg allergy. Win—one less year/month avoiding egg. Worth it family. Probably exception—most >100 not chow hard boiled/scrambled.

More patients really atopic, bad eczema, food numbers terribly high. How tease out? No commercially available 100% fail-proof testing saying numbers falsely elevated—give chickpeas/peanut/cashew.

Dr. Doug Jones: Tangent: sending first BAT Monday—military guy peanuts ~30. Talked Aul—2-3 military BATs.

Dr. Farrah Khan: Basophil activation test—like food challenge in test tube. Introduce food concentrations to blood/cells, see cell degranulates. Not perfect, extra info. Available few US centers—hopefully more widely.

Dr. Tom Chaco: 3-4 waiting, predominantly military. Keep posted—next FAST one, present.

Dr. Doug Jones: Providers listening—come FAST meeting if food allergy treatment options—great conference.

Dr. Farrah Khan: Questions? Go fast oit.org—nonprofit dedicated best practices diagnostics food allergy treatment. Get together yearly—great time.

Can You Compare IgE Levels Between Different Foods or Patients?

Dr. Doug Jones: Quick wrap first segment. Parents comparing IgE numbers: my kid more severe peanut IgE 67, yours 30—or compare peanut/egg. Problem?

Dr. Tom Chaco: Every food different, every patient different. Almond 5/cashew 2 totally different. Ask allergist—non-allergist can't differentiate. Talk specialist.

Dr. Farrah Khan: Number one rule: numbers never predict severity reactions or amount food cause reaction. Not apples-apples comparison.

Dr. Doug Jones: Wrap up: not just parents, pediatricians/mid-levels ordering—aware specific IgE peanut not translate/interpret same as egg/walnut/almond/cashew. Even same test, ridiculous scales, numbers presented same—interpreted different every food/patient. Nuance—more puzzle than number. Don't treat same. Ordering/parents—don't compare. Get allergist experience, knows nuance, proper ordering/interpretation.

That's wrap part one—hope tune next episode part two, dive deep treatment options.

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