FPIES is pronounced “Fees” or “F-Pies,” like “apple pies.” It stands for food protein induced enterocolitis. A food allergy where the immune system is involved, it is a non-IGE mediated reaction meaning a delayed reaction. Unlike more common IGE mediated reactions you find with asthma, inhalant and environmental allergies and your more typical food allergies.
Characteristic of a severe stomach bug, FPIES is often misdiagnosed. Symptoms involve the gut, both small and large intestine, with children experiencing vomiting, diarrhea and low blood pressure. Symptoms usually begin 2-3 hours after eating the problem food. Milk, soy, oats and rice are the most common problem food proteins, however, any food protein can be a trigger.
FPIES is difficult to diagnose as an allergy skin test and blood test often yield negative results. A patch test is currently being studied for its effectiveness in diagnosing and predicting if the problem food is still a trigger. A thorough history and oral food challenge often help in pinpointing the disorder.
Treatment includes IV fluids to combat dehydration with some severe reactions resulting in hospitalizations and steroids. Mild reactions may be treated at home with Pedialyte. FPIES typically ends by early childhood.