It’s really rare for kids to have this type of allergic reaction. Here’s why Canadian researchers are diving deep into causes and symptoms

A rare food allergy that primarily affects infants and young children is so poorly understood by doctors that it can easily be misdiagnosed, warn researchers from the McGill University Health Centre who recently published the first Canadian study on food protein-induced enterocolitis syndrome (FPIES).The study, conducted on 87 children aged one month to 13 years, describes the symptoms and triggers associated with this syndrome, as well as its progression. The young patients were followed at the Montreal Children's Hospital and an affiliated clinic."For very young children, it can eventually lead to dehydration," explained the study's lead author, Dr. Moshe Ben-Shoshan. "But for older children, it's much less dangerous. The problem is that not many people know what it is."FPIES differs from classic food allergies in that it does not involve the antibodies responsible for the allergic reactions that occur within minutes of ingesting the allergen, according to a press release.Therefore, it generally does not cause hives, swelling, breathing difficulties, or anaphylactic shock.The exact causes of the illness are not well understood, but there appears to be a genetic component. "A family history of allergic diseases in nearly 40% of patients further suggests a potential genetic or familial predisposition," the researchers wrote.They then noted that other studies have "highlighted higher rates of allergic comorbidities and a family history of immune-mediated diseases, such as inflammatory bowel disease and celiac disease, in patients with FPIES compared to the general population."Although virtually any food can trigger a reaction, eggs were implicated in about one in three cases, compared to one in five for seafood and one in ten for milk, fish, and peanuts."This may be due to the new (dietary) guidelines that recommend introducing peanuts earlier in a child's life, before the age of one," suggested Dr. Ben-Shoshan.Oats, fruit, and soy were also implicated. Approximately one in 10 children reacted to more than one food. The study authors found that the median age of symptom onset was seven months, and that the majority of reactions occurred before the age of two.Symptoms typically appear between one and four hours after ingestion of the triggering food and often resemble those of gastroenteritis, which can complicate clinical detection, they explained. Vomiting is present in 95% of cases, as is diarrhea.Just over 40% of the children also presented with eczema or atopic dermatitis, while 20% suffered from other food allergies and 14% had asthma. More than a third of the subjects, however, had no other associated conditions.If the syndrome is not recognized, children may be subjected to unnecessary dietary restrictions and "be exposed to an increased risk of nutritional deficiencies at a crucial time in their growth and development," the researchers warned. Diagnosis can be all the more complicated because the allergen that causes the reaction will not elicit any reaction during standard skin sensitivity tests.The news isn't all bad, however, Dr. Ben-Shoshan pointed out."Most of the time it disappears over time," he said. "But it can last a lifetime. With seafood, for example, it's less common to lose the reaction, but it often disappears over time."This study was published in the journal International Archives of Allergy and Immunology.This article has been translated from its original French. Reference:Mulé A., Mulé P., Al Ali A., Prattico C., et al. Food Protein-Induced Enterocolitis Syndrome among Canadian Children Living in Montreal. Int Arch Allergy Immunol. 2026. https://doi.org/10.1159/000552386

It’s really rare for kids to have this type of allergic reaction. Here’s why Canadian researchers are diving deep into causes and symptoms

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