The Allergist

“We need more than just random care. We need randomized care.” — Dr. Derek Chu
For years, the allergy world has been drowning in a sea of data—risk factors, prevention strategies, and enough diagnostic tools to fill a warehouse. But how do you translate 340 different risk factors into a cohesive plan when an anxious parent is sitting in your clinic demanding a skin test for their four-month-old?. On this episode, Dr. Mariam Hanna is joined by "systematic review genius" Dr. Derek Chu to unpack the evidence-based roadmap for food allergy and atopic dermatitis. It’s time to move past the "noise" and start reading between the lines of what our patients actually need.
Key Points:
Major vs. Minor Signals: Eczema severity and family history are the big players, while being first-born or male are merely minor notes in the risk profile.
The Diagnostic Trap: Testing only works if it changes practice; otherwise, you’re just putting a baby through the trauma of an itchy back for a 20% certainty bump.
De-escalating Momentum: Be skeptical of previous "avoid all nuts" labels; if the patient is already eating the food, do not skin test them to it.
The TITAN Initiative: We need national, high-quality food challenge capacity to provide the clarity that families are actually looking for.
Beyond Narrative Synthesis: The new eczema guidelines involve patients as partners and weigh everything from JAK inhibitors to the humble (but low-certainty) bleach bath.
Clean Hands, Frequent Moisture: Prevention of atopic dermatitis may be gray, but moisturizing with every diaper change—using clean hands—is a low-stakes win
Dr. Chu walks us through the "diagnostic momentum" that often leads clinicians to over-test and over-restrict, and why your Royal College exam cutoffs might not be as definitive as you remember. From the major and minor predictors of food allergy to the "multimorbid" patient with eczema, this conversation is a masterclass in being sensible and judicious at the bedside.

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

“We came up with the idea of testing a ketogenic diet… which in mice, it’s basically a lot of Crisco… giving a keto diet to mice with CGD… led to a decreased susceptibility to colitis.” —Dr. Emilia Liana Falcone
The microbiome isn’t something sitting on the sidelines. It’s part of the immune system, interacting with the barrier, shaping responses, and, in IEI, reflecting the underlying defect.
On this episode, Dr. Mariam Hanna is joined by Dr. Emilia Liana Falcone, physician-scientist and director of the Microbiome and Mucosal Defense Research Unit at the Montreal Clinical Research Institute, to walk through how these host–microbe interactions drive disease. From early-life immune programming to microbial signals that activate inflammatory pathways, this is a shift from association to mechanism. And a step toward therapies that target both sides of the equation.
Key Points:
The microbiome reflects the underlying immune defect in IEI
Focus on what microbes are doing, not just which ones are present
Microbiome changes both result from—and contribute to—disease
Early life is a critical window where these interactions are set
Loss of protective microbial functions matters more than specific bacteria
Microbial signals can directly drive inflammation (including inflammasome activation)
Future treatments will likely combine immune therapy with microbiome-targeted approaches
This is not about adding a probiotic.
It’s about understanding how immune defects reshape the microbial environment, and how that environment feeds back into disease.
Get that interaction right, and you’re not just managing symptoms.
You’re changing the system driving them.
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 a safe and very effective therapy, which is probably underutilized within our own community.” —Dr. Susan Wasserman
Subcutaneous immunotherapy (SCIT) sits in that uncomfortable space between routine and risk. It’s one of the few interventions in allergy that can actually modify disease. But it also carries a small, very real risk of severe reactions. On this episode, Dr. Susan Wasserman, professor at McMaster University and a national leader in immunotherapy, walks through what safety really looks like in practice. And where things still go wrong.
Key Points:
Systemic reactions are uncommon but not rare
Safety has improved through better patient selection, standardized extracts, and clinic preparedness
Uncontrolled asthma is the most important risk factor for severe reactions
Prior systemic reactions require reassessment, especially if the cause is correctable
Build-up dosing carries higher risk than maintenance
Rush and cluster protocols increase risk and need clear justification
The 30-minute observation period captures most but not all reactions
Beta blockers and ACE inhibitors may worsen reaction severity without increasing incidence
SCIT is one of the few tools we have that can actually change the trajectory of allergic disease. But it demands discipline. Careful screening. Reliable processes. And a team that’s ready to act when things go sideways.
Because most of the time, it’s safe.
And the rare times it isn’t—that’s where preparation matters most.

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

"So the future is one IV infusion, likely no chemotherapy, and that'll cure our IEIs." — Dr. Nicola Wright
For children born with inborn errors of immunity, bone marrow transplant has long been the closest thing medicine had to a cure. It works — but it comes with chemotherapy, graft-versus-host disease, and a donor search that doesn't always end well. Gene therapy is changing that calculus. Dr. Mariam Hanna speaks with Dr. Nicola Wright, a pediatric hematologist and clinical immunologist at the Alberta Children's Hospital and holder of the Barb Ibbotson Chair of Pediatric Hematology, whose research focuses on developing gene editing platforms for blood and immune disorders.
On this episode, they discuss:
Why bone marrow transplant is, in Dr. Wright's words, "almost a poor man's gene therapy" and what gene therapy offers instead
The spectrum of technologies: lentiviral insertion, CRISPR, base editing, and prime editing. What each does, and where each falls short
Immune reconstitution outcomes across diseases, including over 90% good immune reconstitution in ADA-deficient SCID treated with lentiviral therapy
How to counsel a family when gene therapy might be an option and why most patients still can't access it
The "valley of death": why therapies that work in trials are failing to reach patients, and what it will take to cross it
CAR T-cell therapy in IEI, including a Canadian trial underway for refractory autoimmune disease
What long-term follow-up looks like and why 15-year post-trial monitoring is now an FDA requirement
The science is outpacing the infrastructure. Dr. Wright's vision of shipping cells instead of patients, in vivo delivery via lipid nanoparticle, no chemotherapy required isn't speculative. The runway is being built. The plane is already flying.

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

"That wholesome conversation that you take a minute or two to go through really creates a physician-patient relationship, expands that communication. Probably will not only improve patient outcomes, but reduce medical-legal risk for physicians in the consent process." — Dr. Lisa Thurgur

A signed form isn't consent. It's paperwork. On this episode, Dr. Mariam Hanna is joined by Dr. Lisa Thurgur — emergency physician, award-winning educator, and a physician advisor with the Canadian Medical Protective Association — to unpack what meaningful consent looks like in daily practice. Inadequate consent is one of the most common allegations in CMPA cases, across every specialty.
On this episode:
The three elements of valid consent — and what capacity actually means
Why a signed consent form is not the same as an informed patient
Implied versus expressed consent: when each applies, and when to re-consent
Why serious risks like anaphylaxis — and death — must be disclosed, and how to frame that conversation
Consent in minors: why maturity — not age — determines capacity (with one exception in Quebec)
What to do when parents disagree — or a minor refuses
Patients recording their visits: what physicians need to know
PARQ: a four-point mnemonic for structuring both the conversation and the chart note
The say-back technique: asking patients what they understood, and why it matters
Done well, consent isn't something you do in addition to practicing good medicine. It improves outcomes, strengthens adherence, and reduces medical-legal risk. In other words, it is good medicine.
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