Remission of Acute Food Protein-Induced Enterocolitis Syndrome Confirmed by Oral Food Challenges in Japan

Current and future perspectives on the consensus guideline for food protein-induced enterocolitis syndrome (FPIES)

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE mediated food allergy presenting with delayed onset of projectile vomiting in the absence of cutaneous and respiratory symptoms. The pathophysiology of FPIES remains poorly characterized. The first international consensus guidelines for FPIES were published in 2017 and provided clinicians with parameters on the diagnosis and treatment of FPIES. The guidelines have served as a resource in the recognition and management of FPIES, contributing to an increased awareness of FPIES. Since then, new evidence has emerged, shedding light on adult-onset FPIES, the different phenotypes of FPIES, the recognition of new food triggers, center-specific food challenge protocols and management of acute FPIES. Emerging evidence indicates that FPIES impacts both pediatric and adult population. As a result, there is growing need to tailor the consensus guidelines to capture diagnoses in both patient groups. Furthermore, it is crucial to provide food challenge protocols that meet the needs of both pediatric and adult FPIES patients, as well as the subset of patients with atypical FPIES. This review highlights the evolving clinical evidence relating to FPIES diagnosis and management published since the 2017 International FPIES Guidelines. We will focus on areas where recent published evidence may support evolution or revision of the guidelines.

A nationwide survey of non-IgE-mediated gastrointestinal food allergies in neonates and infants

BACKGROUND

Non-IgE-mediated gastrointestinal food allergies (non-IgE-GIFAs) seem to be increasing rapidly worldwide. However, nationwide studies have been limited to food-protein-induced enterocolitis (FPIES) and food-protein-induced allergic proctocolitis (FPIAP), with little attention to other non-IgE-GIFA subgroups. The aim of this study was to elucidate the clinical features of all patients with non-IgE-GIFAs, not just certain subgroups.

METHODS

We conducted a nationwide cross-sectional survey of non-IgE-GIFAs in Japan from April 2015 through March 2016. A questionnaire was sent to hospitals and clinics throughout Japan. The questionnaire asked about the number of physician-diagnosed non-IgE-GIFA patients, the status of fulfillment of the diagnostic criteria, tentative classification into 4 clusters based on the initial symptoms, the day of onset after birth, complications, and the suspected offending food(s).

RESULTS

The response rate to that questionnaire was 67.6% from hospitals and 47.4% from clinics. Analyses were conducted about "diagnosis-probable" patient cohort (n = 402) and the "diagnosis-confirmed" patients (n = 80). In half of the reported non-IgE-GIFA patients, onset occurred in the neonatal period. The patients were evenly distributed among 4 non-IgE-GIFA clusters. In Cluster 1, with symptoms of vomiting and bloody stool, the onset showed a median of 7 days after birth, which was the earliest among the clusters. Cow's milk was the most common causative food.

CONCLUSIONS

In half of the patients, the onset of non-IgE-GIFAs was in the neonatal period. This highlights the importance of studying the pathogenesis in the fetal and neonatal periods.

Two Pediatric Cases of Food Protein-Induced Enterocolitis Syndrome to Soy Eaten as an Infant Food

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy that can be caused not only by infant formula but also by infant food. Herein, we report two pediatric cases of FPIES to solid soy foods, such as tofu. The patients presented with repetitive vomiting after eating the trigger food as infant food. Although both cases promptly recovered following the cessation of the trigger food, one case required rapid intravenous hydration for compensated shock. Both cases were diagnosed with FPIES to soy based on the typical presentation and parental interviews regarding food exposure. One case had a positive response to an oral food challenge for tofu, and both cases were negative for soy-specific IgE. One of our cases did not develop FPIES from fermented soy products despite having soy-triggered FPIES. The fermentation process may reduce the allergenicity of soy, but further evidence is required to confirm this hypothesis. There are various trigger foods for solid food FPIES (SFF), and these differ among countries. Solid food FPIES to soy is more common in Japan than in other countries due to the frequent use of tofu in infant food. Increased international awareness of the possibility of tofu-triggered FPIES may be warranted due to the rising global use of tofu in infant food.

Food protein-induced enterocolitis syndrome is an important differential diagnosis of vomiting in pediatric emergency

BACKGROUND

The aim of this study was to clarify the clinical characteristics and management of infants with suspected acute food protein-induced enterocolitis syndrome (FPIES) who presented to the pediatric emergency department (ED) before and after the guidelines were published.

METHODS

This was a retrospective cohort study. We classified the infants as "acute FPIES-like symptoms" who were younger than 12 months of age and visited the pediatric ED of the National Center for Child Health and Development due to vomiting 1-4 h after food ingestion without any causative disease, such as infection. The medical records of those infants in 2015 and 2021 were reviewed. We used the nonparametric Mann-Whitney U test to compare two groups for continuous variables, whereas chi-squared or Fisher's exact tests were used for nominal variables.

RESULTS

The number of infants with acute FPIES-like symptoms was 15 (13%) in 2015 and 14 (15%) in 2021. The trigger foods were cow's milk or dairy products in half of the infants, and five as a result of ingestion of hen's eggs in 2021, compared to zero cases in 2015. Five in 2015 and 12 in 2021 required examination at the ED. Three in 2015 and six in 2021 met the diagnostic criteria for acute FPIES in the international consensus guidelines. The emergency physicians did not record at least four minor criteria for acute FPIES in seven in 2015 and five in 2021. No infants (0%) in 2015 and two (14%) in 2021 were referred to the allergy department by an emergency physician.

CONCLUSIONS

Acute FPIES should be considered one of the differential diagnoses of vomiting, and pediatric medical staff should be aware of FPIES diagnostic criteria and appropriately refer suspected cases to a specialist.