# Evaluating the efficacy of a novel home-based oral food challenge protocol for pediatric food protein induced enterocolitis syndrome

## TL;DR

A new home-based method for testing food allergies in children shows high success and safety with no severe reactions.

## Contribution

A novel home-based oral food challenge protocol with gradual dosing for FPIES diagnosis is evaluated for efficacy and safety.

## Key findings

- 80.85% of patients completed the OFC protocol without significant reactions.
- No severe reactions occurred during the protocol.
- Patients reacting to milk were less likely to complete the protocol, though not statistically significant.

## Abstract

Oral food challenges (OFCs) are considered the gold standard for diagnosis of food protein–induced enterocolitis syndrome (FPIES), a non-immunoglobulin E mediated gastrointestinal food allergy characterized by delayed, repetitive vomiting, lethargy, and sometimes diarrhea, primarily affecting infants and young children. Our modified approach to OFCs involves smaller, gradually increased doses to mitigate the risk of severe reactions. We aimed to measure the successful completion of this OFC protocol.

In a retrospective chart review, patients age < 18 years, who had 1 + episode of acute FPIES between 2015 and 2023 were identified using an allergy clinic database. Patients underwent OFCs with home up dosing every 2–4 weeks. Steps included 1%, 2%, 5%, 10%, 20%, 30%, 40%, 60%, 80%, and 100% of the final serving amount. The primary outcome was successful completion, i.e. absence of severe reactions during the OFC protocol and 1 year after. Data were analysed using logistic regression and reported as odds ratios (OR) and 95% confidence intervals (95% CI). Results were adjusted for multiple allergic comorbidities, age of FPIES onset, and biological sex.

Among 47 patients who began the OFC protocol, 38 (80.85%) completed it without significant reactions. Of the 9 (19.14%) who did not complete the protocol, 4 (44.4%) paused due to reactions, and 5 (55.6%) paused due to non-FPIES symptoms. The 4 reactors paused due to mild-to-moderate reactions; there were no severe reactions during the protocol. There were no significant associations identified between OFC completion and severity of symptoms (OR 1.05; 95% CI 0.24–4.71; p = 0.94); age at onset of symptoms (OR 0.99; 95% CI 0.94–1.02; p = 0.58); or age of starting OFC (OR 1.00; 95% CI 0.98–1.02; p = 0.90). Patients who reacted to milk tended to be less likely to complete the protocol than those reacting to other foods (OR 0.28; 95% CI 0.07–1.06; p = 0.06).

This study supports the potential for a home-based gradual approach to OFCs in FPIES, evidenced by a high completion rate and no severe reactions.