Recent Update in Food Protein-Induced Enterocolitis Syndrome: Pathophysiology, Diagnosis, and Management.

Food protein-induced enterocolitis syndrome (FPIES), though first reported in the 1970s, remains poorly understood and likely underdiagnosed. It is a non-immunoglobulin E (IgE)-mediated food allergy syndrome, most commonly identified in infancy and childhood. It can manifest as a constellation of symptoms following food ingestion, including repetitive and projectile emesis (1-4 hours), accompanied by pallor, lethargy, muscular hypotonia, and diarrhea (5-10 hours). In more severe reactions, significant leukocytosis with neutrophilia, thrombocytosis, metabolic derangements, methemoglobinemia, anemia, low albumin, and total protein may be present. Hypotension and ultimately hypovolemic distributive shock may occur in up to 15%-20% of cases. The diagnosis of FPIES is challenging and providers continue to face difficulties in management. This review article aims to highlight the most recent updates in epidemiology, natural history, pathophysiology, potential diagnostic markers, and guidelines for the management of FPIES.