Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy characterized by delayed gastrointestinal symptoms, such as vomiting, after ingesting the trigger food.^1,2 While milk, soy, and grains have long been recognized as common culprits, emerging evidence suggests that egg and peanut are increasingly reported as triggers, raising new clinical concerns.^1,2 Dr. Gail Tan and Dr. Hiral Waghela from the Texas Children’s Hospital presented findings on this topic at the 2025 AAAAI/WAO Joint Congress.^1,2 Their research, based on a retrospective cohort from the multicenter Southwest FPIES registry, provides new insights into the epidemiology and clinical characteristics of egg- and peanut-induced FPIES.^1,2

The study utilized data from a multicenter FPIES registry developed across four medical centers in the Southwest region in the United States: Baylor College of Medicine, University of Texas Southwestern Medical Center, University of Arkansas for Medical Sciences, and University of Texas Dell Medical School.^1,2 The registry, maintained on the BCM REDCap platform, included detailed information on demographics, patient and family history, birth history, diagnosis, food triggers, and biorepository data.^1,2 Patients with an allergist-confirmed diagnosis of FPIES (ICD-10: K52.21) between January 2015 and May 2024 were included in the analysis.^1,2

Among 952 pediatric patients in the registry, 19% (n=181) had egg-induced FPIES.¹ The majority were White (76.8%), non-Hispanic (74.0%), and female (51.4%).¹ The median age of onset was 8 months, and approximately one-quarter (25.4%) achieved tolerance by a median age of 31.5 months.¹ Notably, 77.3% of egg FPIES patients had comorbid atopy, while a family history of FPIES was documented in 7.2%.¹ Egg was the sole trigger in 63.5% of cases, while 28.2% had 2-3 triggers and 8.3% had more than three.¹ Sensitization markers showed positive egg skin testing in 68.0%, with 8.8% of patients exhibiting concurrent IgE-mediated egg allergy.¹ A significant rise in egg FPIES cases was observed after 2017, prompting further research into whether early food allergen introduction plays a role.¹

Additionally, peanut FPIES was identified in 10.5% (n=100) of patients, with a similar demographic distribution—predominantly White (80%), non-Hispanic (78%), and a slight male predominance (51%).² The median age of the first peanut reaction was 7 months, with 25% achieving tolerance at a median age of 29 months.² Among those who underwent skin testing, 78% tested negative, while 22% tested positive.² Comorbid allergic conditions were also prevalent, including eczema (50%) and asthma (14%).² A subset of patients (21%) had IgE-mediated food allergies, and 7% had both FPIES and IgE-mediated peanut allergy, highlighting the diagnostic complexity.²

In conclusion, findings from this large-scale registry reinforce the importance of recognizing egg and peanut as significant FPIES triggers.^1,2 With nearly one in five patients affected by egg-induced FPIES and peanut accounting for over 10% of cases, these allergens warrant greater clinical attention.^1,2 The overlap between FPIES and IgE-mediated allergies, particularly with peanuts, further complicates diagnosis and management.² The increasing incidence of egg FPIES following early allergen introduction suggests a critical period in infancy during which exposure to allergenic foods intersects with a window of susceptibility.¹ A deeper understanding of the presentation, natural history, and comorbidities associated with egg and peanut FPIES could enhance clinical awareness, reduce diagnostic delays, and improve patient outcomes.^1,2