What is FPIES? Symptoms, Risk Factors, and Treatment in Babies
Navigating the world of food allergies can be a daunting experience, especially when it involves something as delicate as your child’s health. One particularly challenging condition is Food Protein-Induced Enterocolitis Syndrome (FPIES), a rare but serious food allergy that typically affects infants and young children.
Unlike typical IgE-mediated food allergies that trigger immediate reactions, FPIES results in delayed and severe gastrointestinal symptoms, making it challenging to identify and manage. In the US, only about 5 out of 1000 children are diagnosed with FPIES, making it relatively rare.
Because identifying and diagnosing FPIES can be tricky, please know that this is not medical advice and is meant to be a general overview. It is important always to get your healthcare provider involved ASAP if you are concerned about FPIES.
In this blog post, we'll explore what FPIES is, its symptoms, possible risk factors, and practical advice on managing this condition to help ensure your baby’s health and comfort. Let’s jump in!
What is FPIES?
Food protein-induced enterocolitis syndrome is a rare, severe, non-IgE-mediated type of food allergy that is based in the gastrointestinal tract. It is sometimes referred to as “delayed food allergy” because it can cause severe vomiting and diarrhea 1 to 4 hours after a trigger food is ingested.
Let’s break down the name to help you better understand the syndrome. Enterocolitis means inflammation of the colon or GI tract, and food protein-induced just means that a food causes the reaction or inflammation.
Unlike typical allergic reactions, FPIES does not involve the immediate immune response that may be detectable through standard allergy tests, such as skin prick tests or blood tests that look for levels of IgE antibodies. Instead, FPIES affects the digestive system and does NOT include any classic skin or respiratory symptoms associated with IgE-mediated food allergies.
FPIES often develops during a baby’s first year of life when the baby is starting solids, and most children outgrow the condition by age 3 or 4. Many symptoms of FPIES can overlap with other illnesses or diseases, so it is essential to always consult with your healthcare provider to determine the diagnosis.
Signs and Symptoms of FPIES in Babies
Identifying FPIES in babies can be challenging due to its delayed onset and the nature of its symptoms. An oral food challenge is sometimes needed if it is unclear whether or not a baby has FPIES because there is currently no other way to confirm the diagnosis.
Diagnosis of FPIES is based on clinical and medical history, symptoms, and physical exam. Most commonly, diagnosis is made if the baby has severe vomiting that usually occurs 1-4 hours after eating the specific food trigger and three or more of the criteria listed below:
A second (or more) episode of repetitive vomiting after eating the same trigger food
A repetitive vomiting episode 1-4 hrs after eating another trigger food
Extreme lethargy, or being unusually tired or weak, with any suspected episode
Marked pallor or paleness of skin color with any suspected episode
An emergency room visit or a need for IV fluids due to dehydration (as indicated by dry mouth, fewer wet diapers, and sunken eyes) after a suspected episode
Diarrhea (as defined by frequent watery stools, sometimes with blood or mucus) within 24 hours
In severe cases, low blood pressure (hypotension) or low body temperature (hypothermia)
A baby who presents with an FPIES reaction will not need typical medications for an IgE-mediated reaction, such as antihistamines like Benadryl or epinephrine (EpiPen). Treatment is typically focused on anti-emetic medicines and oral rehydration.
** Note: These signs and symptoms can be very worrisome and may require immediate medical attention. If you notice them in your child, please contact your baby's pediatrician or take them to the emergency room for evaluation ASAP.
What is chronic FPIES?
Some babies who are repetitively exposed to the trigger food (typically a baby drinking cow’s milk-based formula or soy-based formula) develop a form of chronic FPIES, which is characterized by intermittent vomiting, chronic diarrhea, and/or poor weight gain. The chronic form of FPIES has only been observed in infants.
Common FPIES Trigger Foods in Babies
While age and geographic location can affect trigger foods, cow’s milk, soy, rice, and oats are the common trigger foods for FPIES in babies and young children. Some other select fruits and vegetables, including bananas and sweet potatoes, can be triggers as well. Fish and shellfish are the most common triggers in older children and adults.
** Note: Though FPIES can be caused by multiple foods, about 65-80% of children with FPIES only have one single food trigger. Avoiding these triggers is crucial in managing FPIES and preventing allergic reactions.
Risk Factors for FPIES in Babies
Several factors may increase a baby’s risk of developing FPIES:
- Family history of allergies: A genetic predisposition to atopic conditions or food allergies may be a risk factor
- Presence of other allergies: Babies with a history of food allergies or atopic conditions may be more susceptible.
- Others include cesarean delivery and male sex
FPIES and Breastfeeding
Breast milk is the optimal source of nutrition for infants and is recommended for at least 6 months and beyond when the mother is able.
Note: According to the European Academy of Allergy and Clinical Immunology, breastfeeding in babies with FPIES can typically continue without the mother following an elimination diet.
While FPIES in exclusively breastfed infants is very rare, a breastfeeding mother may need to avoid the trigger food if the baby is symptomatic while the mother is eating it. This is best decided under the guidance of a healthcare provider, such as a registered dietitian or allergist.
It is important to note that the threshold for most babies with FPIES is higher than just ingesting trace amounts of the trigger food. If a baby is asymptomatic and growing well while a breastfeeding mother is eating the trigger food, there is no need for food avoidance by the mom.
FPIES and Formula
Choosing the right formula is essential for babies with FPIES. Standard formulas may contain proteins that can trigger FPIES reactions. A baby with FPIES who is sensitive to cow’s milk should also avoid soy-based formulas due to high rates of co-reactivity.
Hypoallergenic options, such as extensively hydrolyzed formulas or amino acid-based formulas, are often recommended. According to the American Academy of Allergy, Asthma, and Immunology, approximately 10-20% of babies with FPIES will not be able to tolerate extensively hydrolyzed formula, and in this case, they should use an amino acid-based formula.
It’s important to consult with a pediatrician, registered dietitian, or allergist to select the most suitable formula for your baby.
How to Introduce Solid Foods in Babies with FPIES
Many parents of babies with FPIES in my private practice (understandably!) express extreme stress and anxiety about introducing solid foods due to fear of reactions. Keep in mind that most babies with FPIES only react to one food, and the delay of introduction to solids can be detrimental to a baby’s oral motor skills, texture and flavor advancement, and nutritional status.
It is also important to note that most babies do not need an in-office oral food challenge before introducing a new food. In some cases, such as starting a new food in the same food category as another food that induced an extreme FPIES reaction (such as one requiring IV fluids and hospitalization) or in babies with multiple food triggers, an oral food challenge with a medical provider will be recommended. Consult with your healthcare provider about this process if you have concerns.
Babies with FPIES have an increased risk of nutritional deficiencies, usually due to caregivers' apprehension about introducing new foods at home. Below is a short list of considerations to ensure that new foods are introduced safely and effectively.
1. Consult with a healthcare provider: Work with a pediatrician, registered dietitian, or allergist familiar with FPIES to help best monitor the baby’s weight and nutritional status.
2. Start with single-ingredient, lower-risk foods (see below for list): Introduce one new food at a time and wait a few days before trying another.
3. Monitor for reactions: Keep a detailed food diary and observe for any adverse reactions.
4. If serving a higher-risk food (see below for list): Start with a small amount (¼ - 1 tsp) and double the amount slowly over 5-10 days. Serve twice per day (about 6 hours apart).
For example: Day 1 - Offer ¼ tsp at 9 am and ½ tsp at 5 pm
Day 2 - Offer 1 tsp at 9 am and 2 tsp at 5 pm
** Research shows that the severity of the FPIES reaction is usually worse with higher doses of food, so starting small should help reduce any risk of extreme reaction.**
5. If your baby tolerates a new food well: Continue to offer it ~2x per week for several weeks until the food has been well established in the diet.
6. If your baby tolerates food well from one food group: It is safe to introduce another food from the same food group freely without adhering to a specific schedule (for example, if your baby is eating salmon 2x per week without any issues, you can offer tilapia or cod without following a high-risk protocol).
***Note: If a food has a precautionary label that reads “made in a facility that uses [potential trigger food],” it is generally safe for a baby with FPIES to eat that food item unless the baby has had a reaction to a trace amount of the trigger food.
Whether you choose to do a baby-led weaning or traditional spoon-feeding route, make sure to feed responsively by monitoring your baby’s hunger and fullness cues.
What Can Babies Eat When They Have FPIES?
Babies with FPIES can often tolerate most foods, but it varies by individual. It is best to offer nutrient-dense foods that are low-risk first, including certain grains (like quinoa, millet, and amaranth), fruits (like blueberries, peaches, strawberries, and watermelon), vegetables (like broccoli and cauliflower), and protein foods such as meat (beef, lamb, bison, pork).
Because rice and oats are fairly common FPIES triggers, try to offer a wheat or corn product first instead. Look for fortified grains and foods high in iron to make sure your baby's iron needs are met.
These low-risk foods are generally well-tolerated, but it’s important to monitor your baby for any signs of an FPIES reaction. Once your baby is tolerating lower-risk foods well, start to introduce foods that are considered higher-risk, including fish, poultry, soy, eggs, rice, oats, peas, sweet potatoes, bananas, avocados, and ground nuts and seeds.
A high-risk food may also be considered another food in the same food group as one that your baby has already reacted to. For example, introducing turkey if your child reacts to chicken or introducing an oat grain when baby previously reacted to rice.
When Do Babies Outgrow FPIES?
While there is currently no cure for FPIES, many children outgrow it by the age of 3 to 5 years of age. However, the timeline can differ from child to child.
An oral food challenge with an allergist can be performed about 6-18 months after the last FPIES reaction to evaluate the resolution of symptoms. Regular follow-ups with a healthcare provider or allergist can help track the child’s progress and determine when it may be safe to reintroduce previously avoided food or foods.
Individualized support: Starting solids when a baby has FPIES…
Managing FPIES often involves careful monitoring and a tailored approach to diet. By understanding FPIES, recognizing its symptoms, and working closely with healthcare professionals, parents can help ensure their baby's health and well-being.
If you’re interested in learning more about how and when to integrate foods into your baby's diet, as well as how to reduce the risk of food allergies during infancy, check out my new baby-led feeding + food allergy prevention guide and cookbook!
And if you're looking for personalized nutrition support for your babies or kids, I am currently accepting new clients in my virtual private practice.
Thanks for reading!