Food protein-induced enterocolitis syndrome: Current practices in oral food challenge

Background: Oral food challenges (OFC) in food protein-induced enterocolitis syndrome (FPIES) are performed to confirm a diagnosis, test for development of tolerance, and find safe alternatives. Objective: We aimed to define OFC outcomes and identify safer test strategies. Methods: OFCs performed in children with FPIES over a 5-year period were reviewed. Results: A total of 160 OFCs were performed in 59 children (median age, 2.3 years). The most commonly tested foods were hen's egg, fish, and cow's milk. Sixty-six OFC results (41.3%) were positive. Twelve (18.2%) reactions were mild, 18 (27.3%) were moderate, and 36 (54.5%) were severe. Intravenous fluid, ondansetron, and corticosteroids were administered in 83.3, 72.7, and 66.7% of the patients, respectively; one patient required hospitalization. A reaction was most likely with fish (odds ratio [OR] 2.878 [95% confidence interval {CI}, 1.279-6.473]; p = 0.011), and least likely with cow's milk (OR 0.268 [95% CI, 0.082-0.872]; p = 0.029). Of the 36 OFCs with egg yolk, 23 patients had a failed OFC, and of the 17 OFCs with egg white (all tolerant to egg yolk), only 2 patients had a failed result. Interestingly, two patients tolerated baked whole egg but not egg yolk. In cow's milk FPIES, two patients could consume fermented milk but not fresh milk. Of the 11 patients with anchovy-triggered FPIES, 6 tolerated sea bass, and 5 tolerated trout, whereas 4 patients with sea bass FPIES tolerated trout. Conclusion: The search for alternative food species, processing, or subdivision of a trigger food is common practice in FPIES, which reflects the expectations of children and their families. The experience gained can be put into practice and will contribute to the understanding of the disease mechanism.