Oral Food Challenge in Food Protein-Induced Enterocolitis Syndrome by Fish: Is There Any Room for Improvement?

Background: Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food hypersensitivity usually due to cow's milk or soy. Among the solid foods, rice is one of the most causative foods worldwide, but it varies depending on the geographic area. In the Mediterranean countries, fish is one of the most important triggers of FPIES. There is not a specific biological marker for the disease that allows us to confirm the diagnosis or to predict when tolerance to the offending food has been achieved, so all patients with a FPIES diagnosis undergo an oral food challenge (OFC) at least once. The OFC is a risky procedure and many patients develop severe symptoms. Objective: We sought to evaluate the safety of a new OFC protocol in children with fish-FPIES. Methods: A retrospective study was performed over a 22-year period (1996-2018). We compared two methodologies used in the OFC: Method 1 that consisted in giving several doses during the same day versus Method 2 that consisted in giving a unique dose per day on 2 or three non-consecutive days. Results: A total of 75 positive OFC with fish done in 40 children were included. Forty-three (57.3%) OFC were performed following Method 1 and 32 (42.7%) with Method 2.The severity of the symptoms of the OFC done with Method 1 was mostly moderate (41.9%) followed by severe (39.5%) and mild (18.6%). The adverse reactions with Method 2 were mostly mild (68.8%) and only 18.8 and 12.5% presented moderate or severe symptoms, respectively. Conclusions: OFC performed in children with fish-FPIES are risky and many patients develop moderate or severe symptoms after this procedure. We propose a new protocol that has demonstrated to improve safety.