FPIES (Food Protein-Induced Enterocolitis Syndrome)
A delayed food reaction causing severe vomiting in young children
Quick Facts
- Type: Non-IgE food reaction (gut)
- Mainly affects: Infants and young children
- Hallmark: Repeated vomiting 1-4 hours after a trigger food
- Common triggers: Cow's milk, soy, rice, oats
Overview
Food protein-induced enterocolitis syndrome (FPIES) is a type of food reaction that affects the gut, mostly in infants and young children. Unlike a classic food allergy, FPIES does not usually cause hives, swelling, or breathing problems. Instead, it causes delayed, severe, repeated vomiting, and sometimes diarrhea, that begins a few hours after eating a trigger food.
Because the reaction is delayed and does not involve the typical allergy hives or wheezing, FPIES is often confused with a stomach bug or other illness. The reactions can be intense and can lead to dehydration and lethargy. The good news is that most children outgrow FPIES by early childhood. Management centers on identifying and avoiding trigger foods and knowing how to respond to a reaction.
Symptoms
The hallmark is profuse, repeated vomiting that begins about one to four hours after eating the trigger food.
- Repeated, forceful vomiting starting a few hours after the food
- Diarrhea, sometimes hours later
- Paleness and lethargy or floppiness
- Dehydration from fluid loss
- In severe reactions, low body temperature, low blood pressure, and a shock-like state
A severe FPIES reaction can cause a child to become very pale, limp, and unresponsive. This is an emergency, and emergency services should be called right away.
Causes
FPIES is an abnormal reaction of the gut's immune system to certain food proteins.
- Immune reaction in the gut: Specific food proteins trigger inflammation of the intestines, leading to the vomiting and diarrhea. This response is different from the antibody-driven reaction of classic allergies.
- Common trigger foods: Cow's milk and soy are frequent triggers, as are grains such as rice and oats. Other foods, including certain proteins and vegetables, can also be triggers.
A child usually reacts to only one or a few specific foods, and the triggers vary from child to child.
Risk Factors
- Being an infant or young child, when FPIES most often appears
- Introduction of common trigger foods such as milk, soy, rice, or oats
- A personal or family history of other allergic conditions in some cases
Diagnosis
FPIES is diagnosed mainly from the history of reactions, because standard allergy tests are usually normal.
- Clinical history: The pattern of delayed, repeated vomiting a few hours after a specific food is the key to diagnosis.
- Ruling out other causes: Infections and other conditions are excluded.
- Standard allergy tests: Skin and blood allergy tests are typically negative in FPIES, which helps distinguish it from classic food allergy.
- Supervised oral food challenge: In some cases, giving the food under medical supervision confirms the trigger or checks whether the child has outgrown it.
Treatment
Treatment focuses on avoiding triggers and managing reactions when they occur.
- Avoiding trigger foods: Strictly removing the identified foods from the diet prevents reactions.
- Treating an acute reaction: Severe reactions need rehydration, often with fluids given in a medical setting, and supportive care.
- Working with specialists: An allergist and dietitian help identify safe foods, plan nutrition, and guide the safe reintroduction of foods over time.
- Monitoring growth and nutrition: Ensuring the child still gets balanced nutrition while avoiding triggers.
- Outgrowing FPIES: Many children outgrow it, and supervised food challenges can confirm when a food is again tolerated.
Prevention
- Once a trigger is known, avoid that food carefully and check ingredient labels
- Introduce new foods one at a time so reactions can be linked to a specific food
- Have a written action plan from your child's care team for managing reactions
- Inform caregivers, family, and childcare providers about the trigger foods
- Only reintroduce trigger foods under medical guidance
When to See a Doctor
See a doctor if your child has repeated episodes of severe vomiting a few hours after eating, so the cause can be identified. Call emergency services or go to the emergency department right away if your child becomes very pale, limp, unresponsive, or extremely lethargic, or shows signs of severe dehydration such as no wet diapers, sunken eyes, or difficulty waking. Severe FPIES reactions can cause a shock-like state and need urgent treatment with fluids.
Frequently Asked Questions
What is FPIES?
FPIES, or food protein-induced enterocolitis syndrome, is a non-allergic food reaction affecting the gut, mostly in infants and young children. It causes delayed, severe, repeated vomiting and sometimes diarrhea a few hours after eating a trigger food, without the hives or wheezing of classic allergy.
How is FPIES different from a regular food allergy?
A classic food allergy is usually immediate and causes hives, swelling, or breathing trouble, and shows up on standard allergy tests. FPIES is delayed, mainly causes vomiting and diarrhea hours later, and standard allergy tests are typically negative.
What foods most often trigger FPIES?
Common triggers include cow's milk and soy, as well as grains such as rice and oats. Other foods can also trigger it, and each child usually reacts to only one or a few specific foods.
Do children outgrow FPIES?
Yes, most children outgrow FPIES by early childhood. Whether a food can be safely reintroduced is usually checked with a supervised oral food challenge under medical guidance.
When is an FPIES reaction an emergency?
Call emergency services if a child becomes very pale, limp, unresponsive, or extremely lethargic, or shows severe dehydration such as no wet diapers or difficulty waking. Severe reactions can cause a shock-like state that needs urgent fluids and care.
References
- American Academy of Allergy, Asthma & Immunology (AAAAI). Food Protein-Induced Enterocolitis Syndrome (FPIES).
- MedlinePlus, U.S. National Library of Medicine. Food allergy.
- American Academy of Pediatrics (AAP). Food allergies in children.
- National Institute of Allergy and Infectious Diseases (NIAID). Food Allergy.