Food protein-induced enterocolitis syndrome (FPIES) is an uncommon food allergy that presents mostly in infants. The main symptoms include vomiting, lethargy, pallor, and diarrhea, often triggered by typical weaning foods, such as cow’s milk, soy, rice, and oats. In contrast with other food allergies, FPIES presents with a delayed reaction, 2-4 hours after ingesting the food. Due to the profuse vomiting, infants can experience dehydration, or in more severe cases, go into shock during the acute phase of the disease. In more chronic cases, failure to thrive and malnutrition may occur if parents do not seek medical help. FPIES is a clinical diagnosis that can be challenging to identify, because it can mimic other illnesses, such as viral gastroenteritis or sepsis, in infants. There is often significant delay between presentation and diagnosis.

For a retrospective case notes review study published in Annals of Allergy, Asthma and Immunology, my colleagues and I examined the responsible food triggers, as well as the characteristics and management, of FPIES in 74 infants during 2015-2017. We found that rice was the most common trigger among children affected by FPIES in our region (milk is reported as the most frequent cause in other US geographic locations). Rarer triggers, such as banana and avocado, were also identified as more common for our population. We suspect that this observation is related to different dietary and weaning habits, with certain foods preferred as weaning foods in our area compared with other areas in the US.

We noted a 6-month delay in the diagnosis of FPIES, and 22% of infants in our study received a sepsis work-up, highlighting the difficulty in differentiating between FPIES and sepsis in young infants, especially at initial presentation. We also observed a significant percentage of infants at risk for malnutrition because parents became worried about introducing other foods. Infants with FPIES may suffer from very limited and restricted diets; therefore, consulting a dietitian is a key part of managing the disease. Families should receive education on appropriate food introduction.

Physicians need to be able to recognize FPIES in order to minimize delay in the diagnosis, which can be a significant source of anxiety for families and nutritional burden on the affected infant. Future research should focus on the disease’s mechanism, potential diagnostic tools, and identification of risk factors.