Food Protein-Induced Enterocolitis Syndrome: Proposals for New Definitions

Severity Trend of Recurrence in Pediatric Food Protein-Induced Enterocolitis Syndrome

BACKGROUND

Reintroduction of the offending food in pediatric patients affected by food protein-induced enterocolitis syndrome (FPIES) is carried out in hospitals with an oral food challenge (OFC), which leads to a long waiting time and increases the societal burden of medical cost and human resources.

OBJECTIVE

To assess the severity trend of acute FPIES adverse reactions over time in the same patient for possible outpatient or home reintroduction of the offending food.

METHODS

All children (aged <18 years) with a diagnosis of acute FPIES referred to two Italian pediatric allergy clinics were retrospectively enrolled. To determine whether home or outpatient clinic reintroduction of trigger food was possible, a risk of severe reactions of 5% or less was arbitrarily considered acceptable.

RESULTS

Of202 patients enrolled, 23 (11.4%) had increasing severity from mild to moderate up to severe episodes. No variables analyzed in these patients (sex, age at onset, and the interval between the first and severe episodes) had a statistically significant influence on the risk of more severe reactions. Of all patients who initially presented with mild or moderate episodes, 15.2% and 13.9% later manifested severe episodes over time, respectively. Of patients with cow's milk FPIES that started with a mild episode, 5.5% later experienced a severe episode.

CONCLUSIONS

Performing OFC for acute FPIES is not safe enough at home because the probability of severe adverse reaction is greater than 5%. However, it could be considered to perform OFC in an outpatient clinic in patients with cow's milk FPIES who started with a mild episode and if a rapid transfer plan to emergency department is available.

[Differential diagnosis in food allergy]

It is important to establish the differential diagnosis of food allergy with other disorders, for example: toxic reactions that occur in any person exposed to a sufficient amount of some allergen, and non-toxic reactions that depend on individual susceptibility (food allergy or intolerance). The differential diagnosis is decisive to establish the appropriate treatment. Food intolerance involves adverse reactions to foods without any immunological response involved, and commonly manifests with gastrointestinal symptoms (malaise, abdominal pain or diarrhea). Food allergy is an exaggerated reaction of the immune system, often mediated by IgE, that can trigger serious symptoms (hives, inflammation, respiratory distress, even anaphylaxis). The complex thing is because the symptoms sometimes overlap. To establish an accurate diagnosis, exhaustive clinical evaluation, laboratory tests and, in some cases, controlled provocation tests are required. It is important to understand these distinctions, because treatment and management vary significantly. Food intolerance involves the elimination or reduction of the food that triggers the allergic reaction and requires rigorous measures (complete avoidance of the allergen and availability of epinephrine in cases of severe reactions).

[Non-IgE-mediated food allergy]

Food allergy is an immune response to proteins in food. It usually affects 8% of children and 2% of adults in Western countries. Non-IgE-mediated food allergy mainly affects the gastrointestinal tract. Gastrointestinal food allergies are classified, by their underlying pathogenesis, as: IgE-mediated, non-IgE-mediated, or mixed. The symptoms of patients with food protein-induced allergic proctocolitis originate from local inflammation of the distal colon, which causes hematochezia in neonates. It can affect the entire gastrointestinal tract and cause symptoms of intractable emesis, with subsequent metabolic disorders and hypovolemic shock. Food protein-induced enterocolitis syndrome is a non-IgE-mediated allergy that usually appears in childhood, with prolonged repetitive vomiting, starting 1 to 4 hours after ingestion of food. The manifestation in adults is usually triggered by the consumption of shellfish. Atopic diseases affect 40-60% of patients with food protein- induced enterocolitis syndrome, including 40-50% of those with food protein-induced enteropathy and proctocolitis. Probiotics (Lactobacillus GG) can alleviate the symptoms of allergic proctocolitis induced by food proteins, by altering the composition of the intestinal microbiota. Fecal microbiota transplantation (FMT) can change intestinal microecology efficiently compared to food or probiotics.

Update on Food protein-induced enterocolitis syndrome (FPIES)

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE mediated food allergy (FA) characterized by delayed and severe gastrointestinal symptoms that typically occurs within the first year of life. Many aspects of this pathology are currently unclear. FPIES is classified as a non-IgE immune-mediated FA in which the immune response is thought to act mainly through cell-mediated mechanisms. In patients with FPIES, the symptom pattern is determined by the frequency and dose of food allergen in the diet. Diagnosis of FPIES may be difficult, mainly due to the lack of specific biomarkers to confirm or exclude the diagnosis. FPIES is a clinical diagnosis, mainly based on clinical features which, although not specific, are reproducible every time the patient takes the food. Different diagnostic criteria of FPIES were published over time in the literature. The present narrative review aims to analyze the current clinical evidence in epidemiology, pathophysiology, diagnosis, and management of this condition.

'Diagnosing food protein-induced enterocolitis syndrome'

Food protein-induced enterocolitis syndrome is still a mysterious disease, pathogenically poorly characterized, although the first FPIES case has been described in 1967. Mainly, food protein-induced enterocolitis syndrome diagnosis is based on clinical history. The oral food challenge remains the gold standard to confirm the diagnosis, especially in particular situations. Although there are no diagnostic laboratory or imaging tests which are specific for diagnosis, they could, however, sometimes be helpful to rule out clinical conditions which are similar to food protein-induced enterocolitis syndrome reactions. The purpose of this review is to define the clinical features of FPIES and to summarize the current available tools for the diagnosis of FPIES. This review is intended to be a practical guide for the clinician facing a patient with food protein-induced enterocolitis syndrome avoiding delayed diagnosis with unnecessary laboratory tests and detrimental treatments. Moreover, it highlights the unmet needs in diagnosis that require urgent attention from the scientific community to improve the management of patients with FPIES.

FPIES in exclusively breastfed infants: two case reports and review of the literature

Background

Food Protein-Induced Enterocolitis Syndrome (FPIES) is a non IgE-mediated food allergy that generally affects children in the first year of life. Usually symptoms break out when formula milk or solid foods are introduced for the first time but they might also appear in exclusively breastfed infants, since the trigger elements, especially cow’s milk proteins, can be conveyed by maternal milk as well. FPIES in exclusively breastfed babies is a very rare clinical condition and only few cases have been reported in the medical literature.

Case presentation

We describe two cases of FPIES in exclusively breastfed babies. The first one is a two-month-old infant with a brief history of vomit and diarrhea that presented to the Emergency Department in septic-like conditions. The main laboratory finding was a significant increase in methemoglobin (13%). Clinically, we noted that, when breastfeeding was suspended, diarrhea drastically improved, and vice versa when maternal milk was reintroduced. An amino acid-based formula allowed a complete normalization of the symptoms. The second one is a three-month-old infant admitted for a 3 days history of persistent vomit and diarrhea. Blood tests showed a raised level of methemoglobin (7%). An esophagogastroduodenoscopy was performed and biopsies showed an eosinophilic infiltration of the duodenal mucosa. A maternal exclusion diet and an amino acid-based formula allowed a rapid regularization of the bowel function.

Conclusions

We searched all the cases of FPIES in exclusively breastfed babies reported in the medical literature, identifying eight patients, with an average age of 3 months (range 15 days – 6 months). The majority of the cases were initially diagnosed as gastroenteritis or sepsis, five cases were characterized by an acute on chronic scenario and cow’s milk was the most frequently involved food. Methemoglobin was never tested. An oral food challenge test was performed in two patients.

FPIES in exclusively breastfed infants is a rare condition that, in the presence of compatible history and symptoms, should be considered also in exclusively breastfed babies. The evaluation of methemoglobin can simplify the diagnostic process.