What Is FPIES and Can it Be Outgrown?


Food Protein Induced Enterocolitis Syndrome, or FPIES, is a rare type of food allergy that affects young children. Soy and milk proteins are the main triggers, and the symptoms of reactions include vomiting and diarrhea. These reactions range from mild to severe. Just how many children develop this allergy, which cannot be diagnosed the same way as other food allergies, is uncertain, but fortunately most will outgrow it.

FPIES: The Basics

This rare disorder is an allergic reaction to proteins in certain foods that affects the gastrointestinal system. Reactions begin between two and six hours after eating the trigger food and include a lot of vomiting and diarrhea. The reaction can be severe enough that a child needs emergency treatment and rehydration with IV fluids. Other symptoms include abdominal swelling, lethargy and pallor. Most commonly soy and milk proteins trigger FPIES reactions, but rice is also an offender and any other type of food protein could potentially cause a reaction.

How Is FPIES Different From Other Food Allergies?

Most food allergies are IgE-mediated. IgE is immunoglobulin E, an antibody that the immune system makes when an allergic person consumes an allergen. The IgE attacks the allergen and triggers the immune response that constitutes an allergic reaction. FPIES is not IgE-mediated. The reaction the kids with FPIES experience is caused by the immune system, but it is thought to be mediated by immune cells rather than IgE. Because of this, FPIES cannot be diagnosed with skin prick tests like other allergies.


The exact prevalence of FPIES is not known, but it is rare. It seems to be slightly more common in boys than in girls, and like other food allergies, more cases have been diagnosed in recent years. Because of its rarity and how difficult it is to diagnose (it is often misdiagnosed as a viral or bacterial infection), it is difficult to know how many people have FPIES. Studies in other countries have made estimates of around 0.34 percent of the population. FPIES most often develops in infants and very young children. Extremely rare cases have been recorded of older children or adults developing the syndrome after eating shellfish.

FPIES Is Serious

Reactions to allergens in infants and kids with FPIES are often severe with extreme vomiting and diarrhea. These youngsters are often diagnosed with failure to thrive because the condition causes them to be undernourished or malnourished. They can also become dangerously dehydrated or develop into a sepsis-like state of shock. Both of these situations require emergency treatment or the child or infant could die.

Reactions can be treated successfully, but there is no therapy or treatment that cures the condition. The only real treatment is to avoid known allergens that cause the reactions. It is also crucial that young children and babies with FPIES are regularly monitored for nutritional intake and development.

If You Think Your Child May Have FPIES

If your infant or child is vomiting or experiencing diarrhea, see your pediatrician right away. If you suspect FPIES you may also want to be referred to an allergist. Diagnosing FPIES is tricky, and you will probably have to spend a lot of time recording what your child eats, testing him with various foods one at a time, and waiting hours to find out if he will have a reaction. Your doctor or allergist will rely on your child’s history and your food diaries and observations to make a diagnosis. Don’t test foods without the guidance of a doctor, though. Let your pediatrician or allergist come up with a plan for testing and recording foods so you can do it as safely as possible.

FPIES can be very serious, but the good news is that most children outgrow it by the age of three, some by five or six. In even rarer cases of FPIES, a child may have reactions to all but a handful of foods. For most kids with FPIES, though, there will be just one or two triggers, which makes it easier to prevent reactions. If your child has FPIES you will need to control his diet carefully, but if you do he can live without reactions.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.