Food protein-induced enterocolitis syndrome (FPIES)

Important information:

Food protein-induced enterocolitis syndrome (FPIES) is a type of food allergy that affects the GI tract (a non-IgE mediated food allergy). Unlike typical food allergies, symptoms do not develop right away and do not include hives, swelling, or wheezing. Any food can be a trigger although the most common triggers are milk, soy, rice and oat. Symptoms of FPIES usually include delayed vomiting, diarrhea, and lethargy (sleepiness) 2-3 hours after eating the food. FPIES typically starts within the first year of life.

The type of FPIES depends on when symptoms begin and how long they last.

Key features of FPIES

• Standard food allergy skin and blood tests are typically negative.

• Acute reactions are treated with intravenous fluids (IVFs) to treat dehydration, not epinephrine (Epipen®). At times, ondansetron is recommended for severe vomiting although may to be given through an IV.

• Some patients may outgrow specific food triggers after avoiding the food for 12 to 18 months. Talk with your clinician before adding back into the diet.

• Most children outgrow FPIES by 4 years of age.

Symptoms of FPIES

• Repeated vomiting 2 to 4 hours after food ingestion

• May be followed later by diarrhea

• Lethargy (sleepiness) and dehydration (more severe, acute reactions)

• In patients with chronic FPIES, progressively worsening vomiting, diarrhea, and growth concerns

Which foods cause FPIES reactions?

• Cow’s milk and soy (most common)

• Oat and rice (most common solid food)

• Other common triggers include sweet potatoes, squash, peas, and banana

• Any food can cause a reaction and some children may react to multiple foods

Diagnosis

Diagnosis of FPIES includes a complete medical history, identification of symptoms, and ruling out other possible causes such as infections or inflammatory bowel disease (IBD). A “classic” history of repeated reactions (severe, repetitive vomiting starting 2 to 4 hours after food ingestion) is enough to confirm the diagnosis.

In less clear cases, your child will eat the food in a controlled setting, also known as a food challenge, to confirm diagnosis. Most children with FPIES do not have any allergy antibody (immunoglobulin E, or IgE) for the causal food. We don’t fully understand the cause of FPIES, but it is believed that white blood cells in the gut react to the food. This causes inflammation in the intestines, and perhaps causes a more generalized response in the bone marrow. Skin testing and blood work for food allergies is not helpful in diagnosing this type of food allergy.

Patient instructions: Treating FPIES

• Avoid the food that is causing your child to have a reaction. For cow’s milk and soy allergic patients, changing to a special formula is recommended.

• For accidental ingestions, preventing and treating dehydration key. For severe reactions, first-line treatment is intravenous fluids (IVFs) rather than epinephrine and antihistamines. Sometimes, an anti-nausea medicine (ondansetron) is trialed.

• Parents should take their children to the emergency room (ER) with severe reactions. The goal of treatment is to stabilize blood pressure and provide treatment for dehydration in order to avoidshock.

• Develop an action plan in case of an accidental ingestion. This plan can be described in a letter to bring to the ER, which describes FPIES, your child’s triggers, and a proper treatment plan. The ER will look for other causes of symptoms, but FPIES should also be considered.

• Most children outgrow FPIES by 4 years of age. Though some children may not outgrow it until later. Food challenges are sometimes needed before reintroducing the food. Food challenges are done 12 to 18 months after the food is completely avoided.

• Your child’s treatment team may include your primary care provider, an allergist, a gastroenterologist, and a registered dietitian who will work together to make a treatment plan for your child during a joint FPIES clinic. Some children may not need to see all three specialists. We will help guide you through starting new foods to make sure your child gets the nutrients they need to grow and develop feeding skills on time.

• Remember a child with FPIES can still get stomach viruses or have other causes of vomiting.

Additional resources to learn more about FPIES:

• Food Allergy Research and Education (FARE)

• International FPIES Association

• Kids with Food Allergies

To contact the CHOP Food Protein-Induced Enterocolitis Syndrome (FPIES) Clinic, please call 215-590-2549

Reviewed May2024 by Megan Lewis, MSN, CRNP and Laura Gober, MD