Food Protein-Induced Enterocolitis Syndrome (FPIES)

If you are a family dealing with FPIES, you are not alone.

This rare but serious type of food allergy affects the gastrointestinal system. Unlike more familiar food allergies, FPIES doesn’t involve hives or breathing trouble, like typical IgE allergies. Instead, it is cell-mediated, causing delayed symptoms like profuse vomiting, diarrhoea, lethargy, and even shock, often 2 - 3 hours after eating a trigger food.

Our experience with FPIES When my husband and I began transitioning our child from breastmilk to solid foods, he started vomiting. We didn’t think much of it—after all, weaning was a new experience and some babies spit up or react to new tastes.

A few days into commencing solids, in addition to breastmilk, I fed our son another small portion of food. A while later, I quickly stepped away for a shower, leaving him safely in his playpen. When I returned, I was startled to find him lying on a blanket soaked in liquid. Unsure of what had happened, I picked him up—only to realise he was going into shock.

I immediately called an ambulance. Being only six months old, several responders struggled to reach his small veins, which meant that my son remained mostly unconscious until we reached the children's hospital. Thankfully, once there, he received fluid, and quickly came to. Despite the trauma, he suffered no cognitive damage, but the years that followed were filled with caution and anxiety around food. Every new introduction required careful planning and watchful eyes, along with medical support nearby if something were to happen.

Photo: Derek Owen

FPIES is complex and poorly understood. It is also difficult to diagnose. It cannot be detected using traditional allergy testing methods, such as skin prick or blood tests that measure IgE antibodies. Shortly after the incident, our son was subjected to a series of tests, from blood work to an uncomfortable Electrocardiogram (ECG), to determine if he had a seizure. Through my own research, and the support of my sister — a neonatal specialist — I discovered that my son's hypovolemic shock from profuse vomiting was likely FPIES, Food Protein-Induced Enterocolitis Syndrome. I shared this with our paediatrician and the medical team, many of whom had never heard of it. Even for the allergy expert, this was a novel case, only known from reading primary research.

Commonly Reported FPIES Trigger Foods

FPIES Common triggers? In our case it was sweet potato and eggs, although it can also be other seemingly "mild" first foods. This can make weaning or introducing solids a scary experience for families. But with the right support, it's possible to nourish your little one safely. Below are the commonly reported food triggers in literary research. (Note: Children may still react to foods not on this list.)

Liquids	Cow's milk, soy milk, goat's milk
Grains	Rice, oat, barley, wheat
Vegetables	Sweet potatoes, squash, pumpkin, corn, carrots, white potato, spinach, cauliflower, cucumber
Legumes	Green pea, peanut, string bean, green bean, lentil, kidney bean
Fruits	Banana, orange, pineapple, apple, strawberry, blueberry, raspberry, mango, peach, pear, plum, apricot, grape, cherry, kiwi, watermelon, avocado, coconut, tomato
Animal protein	Egg, chicken, turkey, beef, lamb, pork, duck
Seafood	Fish, shellfish, mollusks
Other	Almond, other tree nuts, mushroom, quorn, probiotic Saccharomyces boulardii

Tips for Introducing Foods Safely with FPIES

1. Work with a qualified team Partner with an allergist and a nutritionist who have experience with FPIES. Introducing new foods slowly and with medical guidance can help minimise risk and build confidence.
   

2. Track everything. Keep a detailed food and symptom diary. Because FPIES reactions can be delayed by several hours, thorough tracking is key to identifying potential triggers.
   

3. Have an emergency plan. Whenever we introduced new proteins (from all foods), we informed our paediatrician, and remained nearby for the next hours. Before trialing new foods, make sure you know when and where to seek help, and ensure caregivers are informed too. A written action plan can be a lifesaver in a crisis.
   

4. Stay hopeful. Most children outgrow FPIES by ages 3 to 5. Research is ongoing, and more awareness is growing among healthcare professionals each year.

Clinical Resolution of FPIES Confirmed Through Oral Food Challenge In time, our family developed a personalised approach that brought joy back into mealtimes. Our son officially outgrew FPIES around age 4.5. His final food challenge with beef at the children's hospital was a success, and we were overjoyed — also a bit in disbelief — when there was no reaction.

For years afterwards, we have carried an EPI pen, due to our son being deemed an "allergy" type. This is because, in 25% of cases, this allergy can turn into an IgE allergic response, leading to anaphylactic shock. Fortunately, our son continues to enjoy all kinds of foods without any further allergic reactions.

If you're navigating how to approach trialing foods, how to feed your child with care while managing FPIES, and are looking for support from a paediatric nutritionist, I can offer support and guidance in helping to pave a safe and nourishing path forward.

KATHLEEN KARIUS FUNCTIONAL NUTRITION AND WELLBEING