Food Protein–Induced Enterocolitis Syndrome Food Challenges: Experience from a Large Referral Center

Background: Food protein–induced enterocolitis syndrome (FPIES) is a non–IgE-mediated food allergy that is diagnosed based on clinical findings, but can be confirmed with oral food challenge (OFC). OFC is more often performed to assess the development of tolerance. Most studies describing OFCs in FPIES are limited in size. Objective: We sought to describe our experience with OFCs using our FPIES protocol. Patients were given one-third of serving size with a 4-hour observation period, followed by home titration to full dose. Methods: We conducted a retrospective chart review of patients who underwent OFC via the FPIES protocol from 2014 to 2017. Data regarding the history of reaction, age at the time of challenge, and reactions during challenge or with home introduction were collected. Results: A total of 169 OFCs were completed under the FPIES protocol, in 119 patients to 19 different foods. Thirty challenges (18%) were positive, with 17 challenges (10%) during initial challenge and 13 (7.7%) during home dosing. Most reactions during initial challenge required intravenous fluids (IVF), but hypotension was uncommon. One hundred thirty-nine (82%) OFCs were negative with home introduction, indicating tolerance to the challenged foods. The mean age of passing a challenge to milk, soy, and grain was earlier than that of other solid foods. Conclusions: Our data suggest that our FPIES OFC protocol is safe. Early administration of IVF may prevent the development of hypotension. It is difficult to stratify the risk of severe or delayed reaction based on patient characteristics, and more data are needed to identify those appropriate for home introduction.