What is it?
Food Protein Induced Enterocolitis Syndrome (FPIES) is a non-IgE mediated food-induced allergy that affects the gastrointestinal (GI) tract. The condition typically starts in infancy and can cause retracted vomiting, lethargy, pale skin, and decreased body temperature within 1-4 hours after ingestion of the offending food. Diarrhea may also occur 5-10 hours (and up to 24 hours) after the food is eaten. Often the condition is misdiagnosed as sepsis (bacterial infection of the blood), repeated infections, or a GI illness. Hives, wheezing, and angioedema are not characteristics of FPIES.
Common Food Triggers
Cow’s milk and soy are common foods implicated in the condition. As the infant matures and solid foods are being introduced into the diet, barley, oats, rice, poultry, green beans, sweet potato, and squash are common triggers. However, any food has the potential of causing symptoms. Fish and shellfish have been reported to trigger FPIES in older children and adults.
Diagnosis and Testing
Because FPIES is not IgE mediated, skin testing, and blood tests (RAST tests) are not helpful in making the diagnosis. Medically supervised oral challenges to the suspected food are the most telling test to diagnose FPIES, but they are often not needed if a good medical history is taken, and other diagnoses are ruled out.
Avoiding the offending food allergen is key to preventing symptoms. Should a reaction occur, IV fluids to stabilize the blood pressure and treat dehydration is key. IV steroids may be given for a severe reaction, and an oral antiemetic (Ondansetron) can be considered in children greater than 6 months of age.
Most children will outgrow FPIES between 3-5 years old.