Navigating Diagnostic Challenges in Food Protein-Induced Enterocolitis Syndrome

Announcer:
Welcome to On the Frontlines of Food Allergies on ReachMD. On this episode, we’ll hear from Dr. Anna Nowak-Wegrzyn, who’s a Professor of Pediatrics at the New York University School of Medicine and the Director of the Pediatric Allergy Program at Hassenfeld Children’s Hospital at NYU Langone Health. She’ll be discussing challenges in managing food protein-induced enterocolitis syndrome. Here’s Dr. Nowak-Wegrzyn now.

Dr. Nowak-Wegrzyn: 
Food protein-induced enterocolitis syndrome, or FPIES for short, is an IgE-mediated food-allergic disorder that is famous for creating diagnostic dilemmas. The symptoms are confusing in that they are not usually associated with an allergic reaction. They tend to start hours after eating the food, so between one and four hours, or even longer. They are associated with profuse, repetitive vomiting, pallor, low muscle tone, lethargy, and in extreme cases, hypovolemic shock.

So the symptoms are nonspecific, but the timing of the onset of symptoms and the associated features of pallor, lethargy, and low muscle tone are indicators that this could be a food-allergic reaction caused by FPIES. The difficult part is that it requires the recognition, and making a diagnosis requires clinical acumen. So there’s no diagnostic test, laboratory test, or biomarker that can be tested to establish the diagnosis. The clinician has to recognize the constellation of signs and symptoms and some supporting laboratory findings, such as elevation in neutrophils or platelets. In a very severe reaction, there could be metabolic acidosis as well as methemoglobinemia, so sometimes it can be difficult to distinguish FPIES from other gastrointestinal conditions in infants and children, especially if the symptoms are more chronic.

What’s confusing is the lack of classic allergic symptoms. So there’s no itchy skin rash, hives, swelling, coughing, wheezing, or immediate vomiting. But if the constellation of symptoms happens at least twice or three times after the ingestion of the same food, or if there are reactions to other foods that follow the same pattern, especially if the testing for the IgE—which is our go-to test in the classic IgE-mediated food allergy—is negative, then it really indicates that this is high on our differential. We could do a challenge to confirm the diagnosis, but most of the time, we don’t require challenges to confirm the diagnosis. We do perform those challenges to evaluate for resolution over time, because as unpleasant as the symptoms are, FPIES in children and infants is a transient food allergy that usually goes away by age three to five. So by three to five, most children will tolerate the foods that have caused those unpleasant symptoms.

Announcer:
That was Dr. Anna Nowak-Wegrzyn talking about challenges in food protein-induced enterocolitis syndrome management. To access this and other episodes in our series, visit On the Frontlines of Food Allergies on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!