OBJECTIVES: Food protein-induced entercolitis syndrome (FPIES) is a non-IgE-mediated food allergy that presents with severe vomiting 1 to 4 hours after food ingestion accompanied by lethargy, diarrhea, dehydration, and sometimes shock. This study is the first to examine FPIES patients using real-world data. The study aims to estimate the prevalence of FPIES among children ages 0-3, characterize their patient characteristics, and describe their healthcare resource utilization and costs (HRUC).

METHODS: Yearly (2017-2020) prevalence was estimated as the proportion of persons with a FPIES diagnosis among total persons aged 0-3 with at least one day of enrollment in the MarketScan^® Commercial Database. For retrospective analyses, children aged 0-3 years with a FPIES diagnosis between 1/1/2017 and 3/31/2021 were extracted. Patients were required to have enrollment for 6 months after diagnosis (follow-up). HRUC, provider specialties visited, and FPIES-related diagnoses, procedures, and medications were reported during follow-up. Conditions for which FPIES is commonly misdiagnosed were reported (among the subset with pre-diagnosis enrollment). FPIES patients were matched directly to non-FPIES controls on age, sex, and index year, and outcomes were compared.

RESULTS: The prevalence of FPIES among children aged 0-3 increased steadily from 0.06% in 2017 to 0.17% in 2020. The retrospective analysis included 3,561 FPIES patients (median age 8 months) and 35,610 matched controls. FPIES patients had significantly higher healthcare costs ($4,958 vs. $2,697; p<0.001) and significantly more ER visits (17.7% vs. 10.8%; p<0.001). A larger proportion of FPIES patients had evidence of failure to thrive (7.0% vs. 1.9%; p<0.001), atopic dermatitis (14.7% vs. 4.7%; p<0.001), and IgE-mediated food allergies (38.9% vs. 3.2%; p<0.001). FPIES patients were more likely to have a condition for which FPIES is commonly misdiagnosed (30.7% vs. 8.6%; p<0.001).

CONCLUSIONS: The FPIES prevalence is increasing as disease awareness grows. FPIES patients have significant healthcare burden.