Food Protein-Induced Enterocolitis Syndrome (FPIES)

Food Protein-Induced Entercolitis Syndrome (FPIES) is an uncommon, non-IgE-mediated gastrointestinal food allergy disorder that predominantly affects infants and young children. Those with FPIES experience chronic vomiting, diarrhea, and failure to thrive, usually in association with consumption of cow’s milk and soy; and to a lesser degree, some cereal grains such as rice and oat, and even chicken, turkey, and fish.

Encouragingly, most cases of FPIES are outgrown by age 3 or 4. FPIES is a serious condition that can require hospitalization in the most extreme cases. Management of FPIES involves eliminating the offending food or infant formula from the diet. Treatment of FPIES ranges from giving oral electrolytes at home or administering intravenous fluids and monitoring in the hospital.

Diagnosis of FPIES can be a challenge, as this disorder can be mistaken for a viral illness, and food allergy skin and blood tests typically have negative results because the tests are measuring IgE, and FPIES is not IgE- mediated. Researchers have found that those who have positive skin or blood tests could take longer to outgrow FPIES and have the potential to develop IgE-mediated food allergy.

Symptoms begin early in life, typically occurring after the introduction of milk- or soy-based formulas. Those with FPIES to solid foods usually react to rice, oats, barley, or other foods that are introduced after 4 months of age. Unlike an IgE-mediated food allergic reaction that can involve several systems, the symptoms of FPIES are typically confined to the gastrointestinal system and are delayed rather than immediate. These symptoms include vomiting, bloody diarrhea, weight loss, lethargy, and dehydration.

If you suspect that your child has FPIES, consult with an allergist, who will take into account your child’s clinical history and symptoms, and exclude other causes. In some cases, a clinically supervised oral food challenge is necessary to confirm FPIES, though this procedure is not usually necessary with infants who have classic FPIES symptoms that resolve after their diet is altered to eliminate the offending food. An oral food challenge may also be used to determine whether FPIES has been outgrown.

If your child has FPIES, your allergist may advise you to switch to a hypoallergenic formula, such as a casein hydrolysate-based formula. If your child has solid food FPIES, your allergist may suggest introducing yellow fruits and vegetables rather than cereal.

Commonly Asked Questions

Can breastfed babies get FPIES?

Cases of FPIES among exclusively breastfed babies are very rare, but babies who are breastfed and then later transitioned to a milk or soy-based formula can develop FPIES.

Is the connection between FPIES and food allergy hereditary?

Researchers have found that between 40% to 80% of FPIES patients have a family history of atopic diseases and 20% have a family history of food allergy.