The Allergist

“There is nothing magical that happens in your gut that says, ‘oh, now you’re ready for cow’s milk.’ — Dr. Farah Khan

Milk has a special talent for creating chaos in clinic. One day it’s mucousy stools and a terrifying diaper photo, the next it’s hives after yogurt, delayed vomiting with lethargy, or a family that’s been dairy-free for years with no improvement in eczema. On this episode, Dr. Mariam Hanna is joined by pediatric allergist and clinical immunologist Dr. Farah Khan to walk through the many ways “milk problems” show up — and how allergists can avoid overdiagnosis, unnecessary testing, and prolonged elimination diets that may do more harm than good.

On this episode:

• Why allergic proctocolitis (cow’s milk protein intolerance) is often overdiagnosed
• When skin testing and IgE testing are useful 
• Understanding the difference in lactose intolerance 
• How baked milk can be used to improve quality of life in IgE-mediated milk allergy
• What makes FPIES to milk tricky, including earlier-than-expected reactions
• Why dairy elimination for eczema or EOE needs caution and frequent reassessment

Across each of these scenarios, Dr. Khan returns to the same principle: eliminating dairy should never be a one-and-done decision. Revisiting the diagnosis, retrying thoughtfully, and weighing quality of life alongside risk are essential — especially when prolonged avoidance can set the stage for the very allergy clinicians are trying to prevent.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

"This is an allergic disease, and allergists need to help take care of this person." Dr. Seema Aceves

Found yourself scratching your head about how to approach EoE in young patients? Who will go on to develop chronic disease, facing stricture and food impaction from remodelling? Our current approach can feel like it is stuck in the Stone Age. But not to worry, Dr. Seema Aceves will rocket us to the cutting edge of EoE diagnostics and treatment.

Dr. Seema Aceves is Professor of Pediatrics and Medicine at the University of California, San Diego, and Rady Children's Hospital. She directs the Eosinophilic Gastrointestinal Disorders Clinic and leads an NIH- and CURED-funded research program focused on the mechanisms and clinical impact of tissue remodelling in eosinophilic esophagitis.

On this episode, they discuss:

• EoE is a type 2 inflammatory disease, and allergists need to help treat it.
• How remodelling happens when EoE persists.
• Between 95 and 99 per cent of patients have chronic disease.
• The limits of eosinophils as a biomarker.
• Where gastroenterologists fit into EoE care, and where they don't.
• OIT causes EoE in 4 to 5 per cent of cases.
• The role of elimination diets in treating EoE.
• Emerging tools to identify which patients will develop remodelling.

Dr. Aceves keeps returning to one idea: this disease starts early and builds quietly, and allergists have a key role in detecting its advance in time to prevent strictures.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

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Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

There’s a question that’s been circulating widely these days. It’s in the clinic, it’s in the news, and it’s on patients' minds. Why do allergies appear to be increasing? Enter the epithelial barrier hypothesis. This is a developing theory that sees a connection between the ‘atopic march’ and the breakdown of the epithelial barrier.

On today’s episode we speak with Professor Cezmi Akdis. Professor Akdis is a director of the Swiss Institute of Allergy and Asthma Research in Davos and professor at the University of Zurich. His research has been instrumental in the development of the epithelial barrier hypothesis.

We cover:

• What epithelial barrier integrity looks like when it is working
• What epithelial dysfunction looks like
• Evidence for epithelial barrier breakdown 
• Connection between epithelial barrier dysfunction and the atopic march
• Environmental factors common to Western societies, such as detergents, processed food and air pollution, that impact the epithelial barrier
• Opportunities for early intervention to repair the barrier

It can seem like the sources of epithelial dysfunction are just about everywhere but the solution may begin at home.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

"I don't think any asthmatic in this world should have a SABA, ever." 

                                                                                                                —Dr. Paul O'Byrne

Is it asthma? Is it a cold? Will symptoms go away? Will they come back even worse? And how about an inhaler? Do we give one? Which one? And for how long?

Diagnosing and managing mild and moderate asthma can feel like a game of what-ifs. Worse, the treatment only works if patients stick with it, and that's hard when they feel fine.

On this episode of The Allergist, we speak with one of the world's leading authorities in asthma research. Dr. Paul O'Byrne is a professor of medicine at McMaster University whose landmark START and SYGMA trials reshaped how we think about treating mild asthma.

Key points:

• Our understanding of mild asthma has fundamentally shifted.
• SABA-only relief, used as needed, is riskier than we assumed.
• Daily inhaled steroids sharply cut the risk of severe exacerbations.
• But daily adherence is poor. People just don't take it consistently.
• The SYGMA trials were the breakthrough.
• An as-needed ICS-LABA reliever matched daily steroids, with far better uptake.
• More SABA use, more risk. More ICS-LABA use, less. Same reliever, opposite outcome.
• Ease patients in rather than fighting their SABA attachment.
• Most drop the SABA once they see the new approach working.

Getting the diagnosis right takes time but is critical because it's a potentially lifelong label. Keep patients off SABA alone, and make sure every reliever carries a steroid. Simple? Not quite, but a lot clearer.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

“If that medicine is associated with fear of an injection, then we are giving the impression that a diagnosis of food allergy is worse than a life sentence.” 

— Dr. Paul Turner

When it comes to managing anaphylaxis, epinephrine is the gold standard. But even with its life-saving potential, misconceptions abound, and newer delivery methods like nasal and sublingual formulations are raising questions for allergists and patients alike. In this episode, Dr. Mariam Hanna sits down with Dr. Paul Turner, pediatric allergist, clinical immunologist, and global expert on anaphylaxis, to explore the science, controversies, and clinical realities surrounding epinephrine use.

On this episode:

• Anaphylaxis demystified: Why the "ABC" symptoms (airway, breathing, circulation) are crucial for timely diagnosis.
• Epinephrine explained: How it works, why timing matters, and when it’s not enough.
• Alternative delivery methods: Intranasal and sublingual epinephrine—why Dr. Turner is skeptical about their use in clinical practice without robust evidence of efficacy.
• When epi fails: Understanding the limitations of autoinjectors in severe reactions and the role of IV infusions.
• Improving patient confidence: Strategies for addressing fears and teaching appropriate use to improve outcomes.

Whether you're an allergist navigating these evolving treatment landscapes or a clinician seeking clear guidance for patient care, this episode provides critical insights and practical advice. Tune in to strengthen your understanding of epinephrine’s role in anaphylaxis management and gain clarity on when—and how—it should be used.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

"Food, milk and egg ladders look the same, but they're not the same." — Dr. Juan Trujillo

Ladders are close to standard in some clinics now. The evidence that they change the course of anything is still thin. So families are climbing, clinicians are advising, and nobody has settled the question underneath: is a ladder modifying the disease, or is it keeping everyone busy while a child outgrows it on schedule? On this episode, Dr. Mariam Hanna puts that to someone who has lived with the question longer than most.

Dr. Juan Trujillo is a consultant paediatric allergist at Cork University Hospital and a senior lecturer at University College Cork. He is careful not to oversell. There isn't much literature to go on, he says, so ladder practice ends up tracking something else: how many appointments a clinic can offer. In a stretched service, a ladder can mean fewer visits rather than more. When it comes to egg and milk allergies, different ladders, different timelines, different success rates. Clinics tend to treat them as one thing. Trujillo doesn't.

Key points

• The evidence base is incomplete. Practice moved ahead anyway, largely because indefinite avoidance is not a neutral default.
• In resource-limited systems, ladders can reduce appointments rather than generate them.
• Milk and egg are not interchangeable and should not be presented to families as though they are.
• Skin testing, specific IgE and components will diagnose the allergy. They will not give you the threshold, and they will not tell you who is going to climb.
• Counting milligrams of protein overcomplicates what is, for most young children, dietary advancement.
• Age matters. The younger the child, the better the prospects. Older than five, Trujillo approaches with caution.
• Patient selection is doing more of the work than any step-by-step protocol.

In young children, selected carefully and supported properly, ladders are worth doing on practical grounds, whether or not they turn out to be disease modifying. 

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

"...these are chronic conditions that are not going to magically go away when a patient turns 18 or 21." — Dr. William Anderson

Adolescence and early adulthood tend to be a rough stretch for patients with allergic disease. Asthma that used to be well controlled can start to drift. Teenagers take more chances with foods they are meant to avoid, and they show up for fewer of their appointments. Meanwhile the daily management is sliding off the parent and onto a patient who often is not ready to carry it, from refills to the action plan to knowing what to do in an emergency.

On this episode, Dr. Mariam Hanna welcomes back Dr. William Anderson, a pediatric allergist and director of the transition program at Children's Hospital Colorado. Their conversation is about why the shift from pediatric to adult care should begin years before a patient turns 18, how a clinic can actually build a young person's independence, and why he treats transition as a core piece of managing the disease itself.

Key Points

Transition is something you plan for over years, not something that happens on a birthday.

Teenagers and young adults are more likely to lose disease control, miss follow-up, and land in the emergency department.

Starting at 12 to 14 leaves runway to build skills before adult care becomes urgent.

Parents stay in the picture, but the patient has to start talking in appointments and handling refills.

A tool like TRAQ helps, but confirm the answers with the patient.

The work does not have to fall on the physician alone. Nurses, staff, and care coordinators can carry a lot of it.

The real obstacle is usually cultural. Handing over control feels like a loss.

The goal is not to push patients out early. It is to keep a young person from vanishing into the gap between pediatric and adult care. Someone who knows their own medications and can handle a refill or a scare without a parent is far safer than someone who just ages out and hopes.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

“If you are willing to use it and use it quickly, that's what I want you to have.”
— Dr. Jay Lieberman

Epinephrine is everywhere in allergy practice. Prescribed, refilled, demonstrated, repeated. And still, it carries a strange kind of fear. Patients hesitate. Clinicians sometimes hesitate too. Is it dangerous? Is it a last resort? How bad does the reaction have to be before it counts?

On this episode, Dr. Mariam Hanna is joined by Dr. Jay Lieberman, professor of pediatrics at the University of Tennessee and interim division chief of allergy and immunology at Le Bonheur Children's Hospital. He talks through what epinephrine does in the body, where the evidence is still messier than many assume, and how new needle-free options may change whether patients actually use it when it matters.

Key Points

• Epinephrine remains first-line because it targets the major physiologic problems in anaphylaxis.
• Fear of epinephrine still gets in the way of early use.
• Anaphylaxis definitions are useful, but hard to translate for patients.
• Nasal and sublingual routes may reduce the barrier of the needle.
• The best device is still the one the patient will actually use.

Needle-free epinephrine won't answer every question in anaphylaxis care. But it may change the most practical one: not whether patients know they should treat, but whether they actually will.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

“You can have a patient that has normal immunoglobulins and abnormal responses to protein antigens as well. Historically, I’ve seen these patients. They do happen. They are out there.” — Dr. Benjamin Prince

Specific antibody deficiency (SAD) has never been a clean diagnosis. Some patients carry normal immunoglobulins and still land in clinic with recurrent infections and poor vaccine responses. The newer pneumococcal vaccines have scrambled the old testing pathways. This episode covers which parts of the workup still hold up, and where a titre should actually change what you do next.

Dr. Mariam Hanna is joined by Dr. Benjamin Prince, Associate Professor of Pediatrics and Associate Division Chief of Research in Allergy and Immunology at Nationwide Children's Hospital in Columbus, Ohio. He walks through the shifting definition of SAD, what pneumococcal titres can and can't tell you, and how to read testing in the Prevnar 20 era.

Key Points

• Clinical history as the gatekeeper for who gets worked up
• What Prevnar 20 did to polysaccharide response testing
• Reading the patient ahead of the titre
• Recommendation 4.7 and impaired protein-antigen responses
• Pneumococcal titre thresholds: useful, imperfect, lab-dependent
• The management range, from watchful waiting through immunoglobulin replacement

A useful listen for any clinician who has stared at a borderline pneumococcal panel and wondered whether to keep pulling the thread. The lab pathway exists, but the history is still what tells you whether the result will mean anything.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions

“If the asthma is under good control but they are still having these episodes, then I do think that maybe they have a PVFMD component to their breathing issue.” Dr. R. Jun Lin

Patients come into clinic short of breath. It hits during exercise, it looks dramatic, and they may even describe noisy breathing or the feeling that they “can’t get air in.” So we do what clinicians do: we think asthma. We try inhalers. But sometimes, no matter how many puffers are thrown at the problem, nothing changes.

That’s when it may be time to look higher, to the larynx.

On this episode of The Allergist, Dr. Mariam Hanna is joined by Dr. R. Jun Lin, a fellowship-trained laryngologist and chief of the Division of Laryngology at the University of Toronto, for a practical discussion of vocal cord dysfunction, inducible laryngeal obstruction, and paradoxical vocal fold motion disorder. Dr. Lin walks through how these patients present, how to distinguish laryngeal obstruction from asthma, when both may be present, and why respiratory retraining therapy is often the cornerstone of care.

Key Points

• VCD, ILO, EILO, and PVFMD describe the same basic problem through different specialty lenses.
• The key clue: trouble breathing in, not out.
• In teens, it often shows up during warm-up or early competition.
• In adults, common triggers include perfume, bleach, gasoline, cooking fumes, cold air, humidity, speaking, or laughing.
• Asthma and PVFMD can coexist. If asthma is controlled but symptoms persist, think larynx.
• Laryngoscopy is often normal in PVFMD, but helps rule out structural causes.
• Respiratory retraining therapy is the cornerstone of treatment.
• Pursed-lip breathing can reduce the severity and duration of episodes, but patients need to practise it before symptoms peak.
• Food triggers, urticaria, tongue swelling, or rash point away from PVFMD.
• Botox is a last resort, not first-line treatment.

For clinicians, this episode is a reminder that not every dramatic breathing episode starts in the lower airway. When the history points to trouble getting air in, especially with poor response to inhalers, PVFMD deserves a place on the differential.

Have an idea for the show or a comment, send us a text!

Visit the Canadian Society of Allergy and Clinical Immunology

Find an allergist using our helpful tool

Find Dr. Hanna on X, previously Twitter, @PedsAllergyDoc or CSACI @CSACI_ca

The Allergist is produced for CSACI by PodCraft Productions