Food Protein-Induced Enterocolitis Syndrome

Food protein-induced enterocolitis syndrome (FPIES) is a non–IgE-mediated food allergy that manifests with projectile, repetitive emesis that can be followed by diarrhea and may be accompanied by lethargy, hypotonia, hypothermia, hypotension, and metabolic derangements. FPIES usually starts in infancy although onset at older ages is being increasingly recognized. FPIES is not rare, with the cumulative incidence of FPIES in infants estimated to be 0.015% to 0.7%, whereas the population prevalence in the US infants was 0.51%. FPIES diagnosis is challenging and might be missed because of later (1-4 hours) onset of symptoms after food ingestion, lack of typical allergic skin and respiratory symptoms, and food triggers that are perceived to be hypoallergenic. Diagnosis is based on the recognition of symptoms because there are no biomarkers of FPIES. The pathophysiology remains obscure although activation of the innate immune compartment has been detected. Management relies of avoidance of food triggers, treatment of accidental exposures, and periodic re-evaluations with supervised oral food challenges to monitor for resolution. There are no strategies to accelerate development of tolerance in FPIES. Here we review the most important current concepts in epidemiology, pathophysiology, diagnosis, and management of FPIES.