FPIES, Allergic Proctocolitis and Other Non-IgE Driven Allergic GI Diseases (Recording)

This webinar was recorded on July 16th, 2026

A Clinical Imperative for Allergists, Immunologists, and the Broader Care Team

In the landscape of food allergy medicine, Food Protein-Induced Enterocolitis Syndrome — better known as FPIES — occupies a uniquely challenging position. It mimics conditions far outside the allergic spectrum, defies conventional diagnostic testing, and continues to elude timely identification across virtually every clinical setting where it presents. For allergists, immunologists, pulmonologists, primary care clinicians, nurse practitioners, and physician assistants involved in the management of allergic disease, a working command of FPIES is no longer optional. It is essential.

Beyond the IgE Framework: Rethinking Allergic Disease

The majority of clinicians are trained to recognize the IgE-mediated allergic cascade — urticaria, angioedema, bronchospasm, anaphylaxis. These presentations follow a predictable, well-characterized immunologic pathway. FPIES does not.

FPIES is a non-IgE-mediated gastrointestinal food hypersensitivity believed to involve T-cell mediated immune activation targeting the gut mucosa. When a sensitized patient ingests a trigger food protein, the resulting inflammatory response disrupts intestinal barrier integrity, precipitates significant fluid shifts, and produces the syndrome’s defining clinical feature: profuse, repetitive projectile vomiting with onset typically one to four hours post-ingestion.

Critically, the absence of cutaneous or respiratory manifestations means FPIES will never appear on a standard allergy panel or skin prick test. This is not a diagnostic limitation to work around — it is a fundamental characteristic of the condition that must shape clinical reasoning from the outset.

Recognizing the Clinical Presentations

FPIES manifests in two distinct phenotypes, each demanding a different diagnostic lens:

Acute FPIES occurs following intermittent exposure to a trigger food. The presentation is dramatic — repetitive, high-volume vomiting, profound pallor, and marked lethargy that can rapidly progress to a hypovolemic shock-like state. Published data indicate that approximately 20% of acute FPIES reactions present with hemodynamic compromise, frequently prompting emergency evaluations that chase infectious, metabolic, or surgical etiologies before an allergic mechanism is considered.

Chronic FPIES, more commonly observed in formula-fed infants with ongoing exposure to a trigger protein, presents more insidiously — persistent vomiting, intermittent diarrhea, poor weight gain, and failure to thrive. The subtlety of this phenotype makes it particularly susceptible to prolonged misdiagnosis.

Trigger Foods: Challenging Clinical Assumptions

Among the most clinically significant — and counterintuitive — aspects of FPIES is the profile of its most common food triggers. Cow’s milk and soy predominate in infants, while rice and oats rank among the most frequently implicated solid food triggers. The latter is particularly noteworthy: these grains are routinely recommended as first-introduction foods in standard pediatric feeding guidance, meaning well-intentioned dietary advice may inadvertently perpetuate repeated exposure to a trigger protein.

Poultry, fish, and shellfish round out the common trigger profile, with seafood emerging as a more prevalent trigger in older pediatric patients and adults — a population in whom FPIES is increasingly recognized but remains undercharacterized in the literature.

The Diagnostic Challenge: Pattern Recognition Over Biomarkers

There is currently no validated laboratory biomarker or objective diagnostic test for FPIES. Serum IgE, skin prick testing, and component-resolved diagnostics are uniformly uninformative. Diagnosis is built entirely on clinical pattern recognition: a characteristic symptom timeline, a detailed and systematic dietary history, and the methodical exclusion of conditions that mimic FPIES — including sepsis, pyloric stenosis, cyclic vomiting syndrome, and inborn errors of metabolism.

The oral food challenge (OFC), conducted under supervised medical conditions, remains the diagnostic gold standard for both confirming suspected FPIES and evaluating the development of tolerance over time. For the multidisciplinary care team, this underscores the value of coordinated management between allergists, gastroenterologists, and primary care providers — each contributing a distinct perspective to what is inherently a complex diagnostic picture.

Evidence-Based Management Principles

Strict avoidance of identified trigger foods remains the foundation of FPIES management. Most pediatric patients achieve tolerance between ages three and five, though periodic supervised OFCs are necessary to confirm resolution rather than assume it.

For acute reactions, ondansetron has demonstrated meaningful clinical utility in interrupting the vomiting cascade in moderate presentations, with potential to reduce the need for intravenous fluid resuscitation in appropriately selected patients. Severe reactions with hemodynamic compromise require prompt IV access, fluid resuscitation, and close monitoring.

A Shared Responsibility Across the Care Team

The diagnostic delay in FPIES is a systemic problem — one that persists not because the condition is rare, but because awareness across the clinical community remains insufficient. For every member of the care team involved in managing patients with allergic and gastrointestinal conditions, sharpening the index of suspicion for FPIES is among the highest-yield steps available.

Recognizing FPIES earlier means fewer unnecessary investigations, fewer emergency visits, and — most importantly — patients who receive the right diagnosis and the right care without years of unnecessary suffering in between.

About the Speaker:

Theresa A. Bingemann, MD, FAAAAI

Dr. Theresa A. Bingemann earned her medical degree from Rutgers New Jersey Medical School and completed her Internal Medicine-Pediatrics residency at Mount Sinai Hospital, followed by an Allergy and Immunology fellowship at the Mayo Clinic. She is an Associate Professor of Pediatrics and Medicine at the University of Rochester and serves as Program Director for the Allergy and Immunology fellowship program. Dr. Bingemann is actively involved in medical education, national allergy and immunology organizations, and research focused on food allergy, anaphylaxis, and physician well-being.

This Advances webinar is in partnership with the American College of Allergy, Asthma & Immunology. ACAAI offers CMEs for physicians for this webinar. If you are an ACAAI member, you can obtain CME through the member portal for this Advances webinar.

All attendees will be offered a certificate of attendance. No other continuing education credit is provided.

CME is available through ACAAI for this webinar.

Sponsored by the American College of Allergy, Asthma and Immunology