Food Protein-Induced Enterocolitis Syndrome (FPIES)

What is food protein-induced enterocolitis syndrome (FPIES)?

Food protein-induced enterocolitis syndrome (FPIES) is a reaction to certain foods that causes mostly gastrointestinal (GI) symptoms like vomiting and diarrhea. Adverse food reactions happen when your immune system overreacts to something it thinks is harmful. Unlike common food allergies that cause symptoms soon after eating, FPIES symptoms start several hours after eating a trigger food.

FPIES is most common in kids but it can affect adults, too.

What foods trigger FPIES?

While almost any food can trigger an FPIES reaction, the most common include:

• Milk.
• Infant formula.
• Soy.
• Oat.
• Rice.
• Egg.
• Shellfish and other seafood.

Depending on what part of the world you live in, different foods may be more common triggers.

Types of FPIES

FPIES can be chronic or acute:

• Acute FPIES symptoms happen one to four hours after eating a trigger food. Vomiting and diarrhea can be severe. Your symptoms usually clear up within 12 to 24 hours.
• Chronic FPIES symptoms happen when you eat a trigger food often. You have long-term inflammation that causes milder symptoms that can come and go frequently. These symptoms can take three to 10 days to go away after you stop eating a trigger food.

What are the symptoms of FPIES?

FPIES symptoms include:

• Diarrhea (sometimes watery or bloody).
• Abdominal (belly) pain.
• Pale skin (pallor).
• Lethargy (low energy or lower level of consciousness).
• Unintended weight loss.
• Low body temperature (hypothermia).

FPIES symptoms are delayed from when you ate the trigger food — they can start anywhere from one to four hours later. In chronic FPIES, your symptoms can come and go.

What causes FPIES?

Your immune system overreacting to foods it mistakenly thinks are harmful causes FPIES. The immune cells in your digestive system try to get rid of the food by causing swelling in your stomach and intestines. This causes vomiting and diarrhea.

FPIES is non-IgE-mediation, which means the reaction is caused by other immune cells, not IgE antibodies like many other types of allergies. Unlike other food allergies, FPIES doesn’t cause inflammation in your whole body. This means it doesn’t cause anaphylaxis, a dangerous reaction that can cause your airways to swell.

What are the complications of FPIES?

FPIES reactions can lead to life-threatening conditions, including shock (severe low blood pressure) and dehydration.

How is FPIES diagnosed?

Healthcare providers diagnose FPIES by getting a detailed history of your symptoms or your child’s symptoms. They might perform a food challenge test. During this test, you eat small amounts of your trigger food to see if it causes a reaction.

FPIES can be difficult to diagnose and might look like other conditions, like bacterial infections. Your provider might perform allergy blood tests or allergy skin tests to rule out other allergies. If you have FPIES, you won’t necessarily test positive for allergies with these tests.

How is FPIES treated?

Providers may treat episodes of FPIES with:

• Steroids to reduce inflammation.
• IV fluids to prevent or treat dehydration.
• Anti-vomiting medications (antiemetics), like ondansetron (Zofran®).

Can FPIES be prevented?

If you know you or your child has FPIES, you can prevent reactions by avoiding trigger foods. You may need to keep a food diary or try an elimination diet to figure out what foods cause a reaction.

If your baby has FPIES, your provider might suggest some ways to avoid reactions while getting your baby essential nutrition. These include:

• Using hypoallergenic baby formula.
• Introducing fruits and vegetables instead of grains as your child’s first solid foods.
• Following an FPIES food introduction ladder that details how to introduce new foods to your child.

What can I expect if my child or I have FPIES?

Most kids outgrow FPIES by 3 or 4 years old. Your provider might suggest a food challenge test if you want to reintroduce a trigger food. In the meantime, it’s important to figure out which foods are triggers and keep an eye on any reactions. Severe vomiting and diarrhea can be dangerous.

Adults with FPIES can manage it by figuring out their trigger foods and avoiding them. Sometimes, FPIES reactions in adults can go away. But most of the time, FPIES reactions that you develop as an adult will always affect you.

How do I take care of myself with FPIES?

If you have FPIES — or think you do — you may need to track the foods and drinks you consume to figure out what’s causing the reaction. Once you’ve discovered the cause, you can avoid any triggers.

When should I see my healthcare provider?

Talk to your healthcare provider if you think your child is having a reaction to food, formula or milk. Even minor reactions can keep them from getting the nutrition they need. Severe reactions require immediate medical attention.

When should I go to the ER?

Go to an emergency room or seek immediate medical attention if you or your child experiences:

• Confusion or altered mental state.
• Peeing very little or not at all.
• Sunken eyes.
• Swelling of the face, lips or tongue.
• Trouble breathing or swallowing.

What questions should I ask my doctor?

It might be helpful to ask your healthcare provider:

• Is this a food allergy or FPIES?
• How do I figure out what foods trigger FPIES?
• How do I avoid trigger foods while meeting my/my child’s nutritional needs?
• What do I do if I/my child has a reaction?

What is the age of onset for FPIES?

FPIES usually starts in babies around 4 months old, or whenever they’re first introduced to the trigger food. Adult-onset FPIES most often starts after 40.

How common is FPIES in adults?

FPIES is less common in adults than in children. About 1 in 450 (.22%) adults experience FPIES. The most common FPIES trigger food for adults is shellfish.

Can exclusively breastfed babies have FPIES?

It’s uncommon, but yes. Sometimes, breastfed babies can develop FPIES. Proteins from the food you eat and beverages you drink can pass to your child through your milk — though studies on this aren’t definitive.

Is FPIES an autoimmune disease?

No, FPIES isn’t an autoimmune disease. Autoimmune diseases happen when your immune system mistakenly attacks your own cells. FPIES is an immune system reaction to foods or drinks in your digestive tract.

A note from Cleveland Clinic

FPIES is an uncommon condition that can make it difficult for you or your child to get proper nutrition. It can sometimes look like other conditions, and you might have to do some experimenting to determine what food or foods trigger it. A healthcare provider can help you find out what foods to avoid and work with you on strategies for getting proper nutrition — without getting sick.