Food protein-induced enterocolitis syndrome

Food protein-induced enterocolitis syndrome (FPIES) is a systemic, non-immunoglobulin E (IgE)-mediated food allergy to a specific trigger within food, most likely food protein. As opposed to the more common IgE food allergy, which presents within seconds with rash, hives, difficulty breathing or anaphylaxis, FPIES presents with a delayed reaction where vomiting is the primary symptom. In its acute form, FPIES presents with vomiting that typically begins 1 to 4 hours after the trigger of food ingestion, alongside paleness of the skin, lethargy, and potentially blood-tinged diarrhea. In the severe form of acute FPIES, continued vomiting may cause severe dehydration or hypotensive shock-like state, requiring hospitalization. In its chronic form, continued exposure to trigger foods results in chronic or episodic vomiting, poor weight gain, failure to thrive, and watery or blood-tinged diarrhea. FPIES can potentially develop at any age, from infancy to adulthood, but most commonly develops within the first few years of life and resolves in early childhood. Atypical FPIES presents with evidence of specific IgE-sensitization via positive specific serum or skin IgE testing to trigger foods. Atypical FPIES may prolong time to disease resolution or increase risk of conversion to IgE-mediated food allergy.