The evolution of food protein-induced enterocolitis syndrome (FPIES): Global trends, emerging triggers, and natural history.

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy characterized by delayed gastrointestinal symptoms. It is thought that immune and neuroimmune mechanisms drive FPIES pathophysiology, but this remains incompletely understood. There are no specific biomarkers to confirm the FPIES diagnosis, monitor for resolution, or assess reactivity to additional food triggers. FPIES is thought to occur globally, with most literature from industrialized countries. Although the initial reports of FPIES involved infants and toddlers, it is now apparent that the diagnosis can present into adulthood. For children, the major FPIES triggers vary geographically. Cow's milk is a major trigger globally, and other notable triggers including grains in the United States and Australia, fish in Europe, and hen's egg in Japan. In the last decade, there has been a surge in pediatric cases of FPIES to hen's egg in the United States and Japan and peanut in the United States. This rise coincides with implementation of early introduction guidelines that encourage feeding these foods in early infancy. It is hypothesized that there may be a window of FPIES susceptibility in infancy, with trends in FPIES triggers mirroring feeding practices during this period. For adults, seafood is the most common trigger food. Further research into FPIES pathophysiology is needed, as enhanced understanding of the underlying mechanisms, identification of specific biomarkers, and recognition of risk factors for FPIES may guide predictions of future trends and best practices for dietary management.