Current understanding of the immune mechanisms of food protein-induced enterocolitis syndrome

Wheat-Related Disorders in Children: A 360-Degree View

Immunological illnesses related to wheat represent an epidemiologically relevant phenomenon at a pediatric age. The term "Wheat-related disorders" involves a spectrum of diseases: celiac disease, IgE-mediated wheat allergy, non-IgE mediated wheat allergy, wheat-related eosinophilic esophagitis, and non-celiac gluten sensitivity. Their pathogenesis is different. At the same time, wheat represents their common point. This article aims to the state-of-the-art and new clinical evidence in pediatric age.

The clinical and immunological basis of early food introduction in food allergy prevention

IgE-mediated food allergy has an estimated prevalence of 6%-10% in developed countries. Allergen avoidance has long been the main focus in the prevention of food allergy and late solid food introduction after 6-12 months of age was recommended in high-risk infants. However, the rising prevalence of food allergy despite delayed exposure to allergens and the observations that IgE-mediated sensitization to food products could even occur before the introduction of solid foods resulted in a shift towards early solid food introduction as an attempt to prevent IgE-mediated food allergy. Since then, many trials focused on the clinical outcome of early allergen introduction and overall seem to point to a protective effect on the development of IgE-mediated food allergies. For non-IgE-mediated diseases of food allergy, evidence of early food introduction seems less clear. Moreover, data on the underlying immunological processes in early food introduction is lacking. The goal of this review is to summarize the available data of immunological changes in early food introduction to prevent IgE and non-IgE mediated food allergy.

Intestinal protein uptake and IgE-mediated food allergy

Food allergy is affecting 5-8% of young children and 2-4% of adults and seems to be increasing in prevalence. The cause of the increase in food allergy is largely unknown but proposed to be influenced by both environmental and lifestyle factors. Changes in intestinal barrier functions and increased uptake of dietary proteins have been suggested to have a great impact on food allergy. In this review, we aim to give an overview of the gastrointestinal digestion and intestinal barrier function and provide a more detailed description of intestinal protein uptake, including the various routes of epithelial transport, how it may be affected by both intrinsic and extrinsic factors, and the relation to food allergy. Further, we give an overview of in vitro, ex vivo and in vivo techniques available for evaluation of intestinal protein uptake and gut permeability in general. Proteins are digested by gastric, pancreatic and integral brush border enzymes in order to allow for sufficient nutritional uptake. Absorption and transport of dietary proteins across the epithelial layer is known to be dependent on the physicochemical properties of the proteins and their digestion fragments themselves, such as size, solubility and aggregation status. It is believed, that the greater an amount of intact protein or larger peptide fragments that is transported through the epithelial layer, and thus encountered by the mucosal immune system in the gut, the greater is the risk of inducing an adverse allergic response. Proteins may be absorbed across the epithelial barrier by means of various mechanisms, and studies have shown that a transcellular facilitated transport route unique for food allergic individuals are at play for transport of allergens, and that upon mediator release from mast cells an enhanced allergen transport via the paracellular route occurs. This is in contrast to healthy individuals where transcytosis through the enterocytes is the main route of protein uptake. Thus, knowledge on factors affecting intestinal barrier functions and methods for the determination of their impact on protein uptake may be useful in future allergenicity assessments and for development of future preventive and treatment strategies.

Malabsorption Syndromes and Food Intolerance

Feeding intolerance is ubiquitous in neonatal intensive care units with as many signs and symptoms as possible diagnoses. Optimizing nutrition is paramount in both preterm and term infants. Determining the cause of feeding intolerance and adjusting nutrition interventions is an important part of the daily care of newborns. This review discusses the role of malabsorption and food intolerance as possible causes of nutrition difficulties in the newborn.

Adult Food Protein-Induced Enterocolitis Syndrome

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE, cell-mediated food allergy, commonly diagnosed in infants and young children. In recent years, new-onset adult FPIES has been recognized. The underlying pathogenic mechanism of FPIES has yet to be elucidated, thus disease-specific diagnostic biomarkers have yet to be determined and an oral food challenge (OFC) remains the gold-standard for the diagnosis. Pediatric patients with FPIES classically present with symptoms of delayed, repetitive vomiting approximately 1 to 4 hours following ingestion of a food allergen. However, adults with FPIES have been reported to have a different symptom profile and different food triggers compared to the pediatric FPIES population. The current FPIES diagnostic criteria may not be appropriate for the diagnosis of adult FPIES patients, thus an oral food challenge remains a diagnostic tool. This review provides an overview of the current literature on the clinical presentation, epidemiology, diagnosis, triggers and management of adult FPIES.

Food Protein-Induced Enterocolitis Syndrome in Children with Down Syndrome: A Pilot Case-Control Study

Food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobin E-mediated food hypersensitivity disorder. However, little is known about the clinical features of FPIES in patients with Down syndrome (DS). Medical records of children with DS diagnosed at our hospital between 2000 and 2019 were retrospectively reviewed. Among the 43 children with DS, five (11.6%) were diagnosed with FPIES; all cases were severe. In the FPIES group, the median age at onset and tolerance was 84 days and 37.5 months, respectively. Causative foods were cow’s milk formula and wheat. The surgical history of colostomy was significantly higher in the FPIES group than in the non-FPIES group. A colostomy was performed in two children in the FPIES group, both of whom had the most severe symptoms of FPIES, including severe dehydration and metabolic acidosis. The surgical history of colostomy and postoperative nutrition of formula milk feeding may have led to the onset of FPIES. Therefore, an amino acid-based formula should be considered for children who undergo gastrointestinal surgeries, especially colostomy in neonates or early infants. When an acute gastrointestinal disease is suspected in children with DS, FPIES should be considered. This may prevent unnecessary tests and invasive treatments.

The challenging diagnosis of food protein-induced enterocolitis syndrome: A case report series

Food protein-induced enterocolitis syndrome (FPIES) is a type of non-immunoglobulin E (IgE)-mediated food allergy. However, in addition to vomiting and diarrhea, IgE-mediated skin or respiratory symptoms may be comorbidities in some patients with FPIES. We described four unusual cases of neonates with FPIES, whose clinical presentations were variable and misleading. All patients experienced vomiting, diarrhea or other gastrointestinal symptoms, and three of them developed IgE-mediated food allergy. Case 1 was admitted to the hospital with convulsions and then developed severe sepsis and necrotizing enterocolitis (NEC)-like appearance. Case 2 was wrongly diagnosed with Stevens-Johnson syndrome due to a severe extravasation rash of the skin and mucous membranes and a systemic inflammatory response. There was unexplained cholestasis in case 3, which might be attributed to food allergy. Asymptomatic elevation of C-reactive protein was the only hint at early-stage FPIES in case 4. Moreover, there were increased serum food-specific IgG values in three of the above cases. After eliminating the offending food, all of the above clinical manifestations rapidly improved in the four cases; thus, we believe that the most correct diagnosis in the described four cases was FPIES. This case report series should further draw clinicians' attention to FPIES with variable and atypical symptoms. The usefulness of IgG levels in identifying the presence of FPIES is uncertain.

Food protein-induced enterocolitis syndrome: Dynamic relationship among gastrointestinal symptoms, immune response, and the autonomic nervous system

OBJECTIVE

To explore the relationship among gastrointestinal (GI) symptoms, immune response, and autonomic nervous system (ANS) in food protein-induced enterocolitis syndrome (FPIES) in relation to the current understanding of disease phenotype and pathogenesis.

DATA SOURCES

Relevant studies related to FPIES, GI symptomatology, and ANS were reviewed. Literature search was performed using PubMed, with keyword combinations including but not limited to FPIES, allergic GI disorders, ANS, autonomic dysfunction, dysautonomia, GI, diarrhea, vomiting, neuroimmune, and clinical phenotyping tools.

STUDY SELECTIONS

Peer-reviewed case-control studies, observational studies, reviews and guidelines, and systematic reviews related to FPIES and ANS were selected for review.

RESULTS

There is limited research directly relating GI symptoms and FPIES to the ANS and immunologic response. To support the proposed mechanisms of action related to patient symptoms, studies relevant to coexisting GI-autonomic processes and FPIES immunologic triggers were examined. These related disease processes were extrapolated to FPIES based on the current knowledge of FPIES phenotype and pathogenesis.

CONCLUSION

The etiology of FPIES and the underlying mechanisms triggering symptoms are not well understood. On the basis of the exaggerated GI symptoms and hemodynamic response observed, the ANS likely plays an important role in FPIES, possibly as a compensatory response. The trigger for this cascade of symptoms may be related to the disruption of immunologic homeostasis that typically contributes to immune tolerance. To more accurately evaluate FPIES pathophysiology necessitates understanding the diverse spectrum of presenting symptoms. A consistent and comprehensive symptom assessment tool may improve our understanding of this dynamic relationship.

Adults with possible food protein-induced enterocolitis syndrome with crustacean ingestion

Background

Food protein-induced enterocolitis (FPIES), an entity previously thought to only affect children, has been increasingly described in adults. In this study, we report a Canadian cohort of 19 adolescents and adults with recurrent non-immunoglobulin E (IgE)-mediated gastrointestinal symptoms after crustacean ingestion, consistent with FPIES.

Methods

We conducted a retrospective chart review of patients in an outpatient allergy clinic from January 2005 to May 2020. Electronic records were searched using keywords for crustaceans and for symptoms consistent with FPIES. We included patients with gastrointestinal symptoms specifically to crustaceans on more than one occasion, who were 14 years or older at the time of index reaction. Exclusion criteria included symptoms suggestive of an IgE-mediated anaphylactic reaction or a likely alternative diagnosis. We identified 19 patients for our cohort who met the criteria.

Results

Our cohort was 68.4% female (13) and 32.6% (6) male. The average age at first reaction to crustaceans was 34 years old with a range of 14–68 years (median = 28 years; IQR = 32 years). Time from ingestion to beginning of symptoms ranged from 3 min to 6.5 h, with an average of 2.8 h (median = 2 h; IQR = 3.25 h). Duration of reaction ranged from less than a minute to over 48 h, with a mean of 9.4 h (median = 4 h; IQR = 7.75 h). Patients had 4.8 reactions on average; however, number of reactions ranged from 2 to 12.5 (median = 3, IQR = 3). All patients identified a “trigger” food in the crustacean group, and 12 subjects identified additional reactions to other seafood.

Conclusions

This case series will better characterize and advance our understanding of this disease entity in adults. There are key differences in the presentation of FPIES in adults compared to children, namely female predominance, difference in solid food trigger, and unpredictable time course. Future studies are needed to examine the pathophysiology and natural history of adult FPIES. Specific guidelines should be developed for the diagnosis and management in adults.

Trial registration: retrospectively registered.

New insights into food protein-induced enterocolitis in children

Food protein-induced enterocolitis syndrome (FPIES) represents a non-IgE-mediated food allergic disorder with delayed gastrointestinal symptoms that may evolve in a medical emergency. Clinically, FPIES can be distinguished into acute and chronic phenotypes. FPIES is mainly diagnosed in infancy however the onset at older ages is being progressively described. The pathogenetic mechanism underlying FPIES remains mainly unexplained, but an alteration of food-specific T-cell response has been proposed. The diagnosis of FPIES is primarily clinical, since there are not available specific biomarkers. Oral food challenge (OFC) is the gold standard for diagnosing FPIES or excluding the onset of tolerance to the triggering food. Management of FPIES includes an acute phase treatment and a maintenance therapy with the strict food avoidance until challenge, in order to prevent new attacks and avoid nutritional alterations. Acute management requires hydration that can be performed orally or intravenously according to clinical status. Long-term management of FPIES is based on the avoidance of the culprit food(s) and supervised introduction of other high-risk foods if never taken before among infants before 12 months of age. There is a compelling need of future achievements in FPIES research for the definition of underlying disease pathogenesis and potential therapeutic point of care.

Non-IgE-Mediated Gastrointestinal Food Allergies in Children: An Update

Non-immunoglobulin E-mediated gastrointestinal food allergic disorders (non-IgE-GI-FA) include food protein-induced enterocolitis syndrome (FPIES), food protein-induced enteropathy (FPE) and food protein-induced allergic proctocolitis (FPIAP), which present with symptoms of variable severity, affecting the gastrointestinal tract in response to specific dietary antigens. The diagnosis of non-IgE-GI-FA is made clinically, and relies on a constellation of typical symptoms that improve upon removal of the culprit food. When possible, food reintroduction should be attempted, with the documentation of symptoms relapse to establish a conclusive diagnosis. Management includes dietary avoidance, nutritional counselling, and supportive measures in the case of accidental exposure. The prognosis is generally favorable, with the majority of cases resolved before school age. Serial follow-up to establish whether the acquisition of tolerance has occurred is therefore essential in order to avoid unnecessary food restriction and potential consequent nutritional deficiencies. The purpose of this review is to delineate the distinctive clinical features of non-IgE-mediated food allergies presenting with gastrointestinal symptomatology, to summarize our current understanding of the pathogenesis driving these diseases, to discuss recent findings, and to address currents gaps in the knowledge, to guide future management opportunities.

Atopy patch test in children with cow's milk and hen's egg allergy: Do clinical symptoms matter?

INTRODUCTION AND OBJECTIVES

Since early 2000s, atopy patch test (APT) has been used to determine non-IgE and mixed-type food allergies. Previous studies have reported conflicting results about the diagnostic value of APT in food allergies, due to non-standardized methods. We aimed to determine the diagnostic efficacy of APT compared to open oral food challenge (OFC) in patients diagnosed with cow's milk allergy (CMA) and hen's egg allergy (HEA) manifesting as atopic dermatitis (AD) and gastrointestinal system symptoms.

MATERIALS AND METHODS

In patients with suspected AD and/or gastrointestinal manifestations due to CMA and HEA, the results of OFC, APT, skin prick test (SPT) and specific IgE (sIgE) were reviewed. Specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of sIgE, SPT, APT and SPT+APT were calculated.

RESULTS

In total 133 patients with suspected CMA (80) and HEA (53) were included in the study. In patients with CMA presenting with gastrointestinal symptoms, APT had sensitivity of 9.1%, specificity of 100%, PPV of 100% and NPV of 48.7%. In atopic dermatitis patients, sensitivity of APT was 71.4%, specificity 90.6%, PPV 62.5% and NPV 93.6%. In patients diagnosed with HEA, the sensitivity, specificity, PPV and NPV values of APT were 72.0%, 78.6%, 47.2% and 75.0%, respectively. In patients diagnosed with HEA presenting with AD, sensitivity of APT was 87.5%, specificity 70.6%, PPV 73.7% and NPV 85.7%. Atopy patch test had lower sensitivity (44.4%) and higher specificity (90.9%) in patients diagnosed with HEA presenting with gastrointestinal symptoms than those presenting with AD.

CONCLUSION

Our study showed that APT provided reliable diagnostic accuracy in atopic dermatitis patients. However, APT had low sensitivity in patients with gastrointestinal symptoms.

Fecal Changes Following Introduction of Milk in Infants With Outgrowing Non-IgE Cow's Milk Protein Allergy Are Influenced by Previous Consumption of the Probiotic LGG

Cow's milk protein allergy (CMPA) is the most common allergy in the first year of life. Non-IgE mediated CMPA is characterized by digestive symptoms and tolerance development before the age of three. Gut microbiota composition in early life has been associated with food allergy. The ingestion of different foods/nutrients may mark different shifts in the microbial colonization of the infant intestine as well as the consumption of probiotics. Aim: To analyze changes in microbiota composition and metabolic and cytokine profiles in fecal samples from infants with non-IgE mediated CMPA after successful milk challenges, tolerance acquisition, and increasing dairy introduction in their diet. Methods: Twelve children with CMPA, aged between 1 and 2 years old, were recruited for the study. Participants were initially consuming hypoallergenic hydrolyzed formulas (four of them supplemented with the probiotic Lactobacillus rhamnosus GG), before being exposed to a standardized oral challenge (SOC) with cow's milk. Fecal samples were collected before, 1 week, and 1 month after performing the SOC. Changes in gut microbiota were determined by high-throughput amplicon sequencing of the 16S rRNA gene. Levels of lactobacilli were also determined by quantitative PCR (qPCR). Microbial metabolites were analyzed by chromatographic methods and fecal cytokines related to the Th1/Th2 balance were determined by immunoassay. Results: Lactic acid bacteria significantly increased in infants who outgrew non-IgE CMPA, after the introduction of milk. Microbial metabolites derived from the fermentation of proteins, such as branched chain fatty acids, and p-cresol, diminished. After the SOC, some cytokines related to inflammation (TNF-α, IFN-γ) increased. Accompanying the introduction of an unrestricted diet, we found significant differences in fecal microbial composition, metabolites, and cytokines between infants who did not consume the probiotic L. rhamnosus GG and those that did. Conclusions: These findings indicate that the introduction of intact milk proteins is followed by modifications in the infant gut environment through changes in immune mediators, microbiota, and its metabolic end-products. Consumption of probiotics during CMPA may contribute to gut homeostasis by fine-tuning these profiles.

Food Protein-Induced Enterocolitis Syndrome and Proctocolitis

Non-IgE-mediated, also labeled cell-mediated, allergic reactions to foods are more common than usually thought and probably account for approximately more than 40% of cases of cow’s milk allergy during infancy and young childhood. Food allergy is now described in the form of syndromes, among which food protein-induced enterocolitis syndrome (FPIES) and food protein-induced allergic proctocolitis (FPIAP) are gaining increased recognition. FPIES occurs in infancy but may also occur in older children and in adults. The dominant symptom is emesis, repetitive in the chronic FPIES form and explosive in the acute form. Acute FPIES begins 1– 4 h following ingestion of the offending food. Diarrhea is frequent, between 5 and 10 h later, and may be accompanied by lethargy and dehydration, which both characterize severity. Cow’s milk is the most frequent food trigger, followed by soy. FPIES may develop up to 1 year of age, but may also occur in the newborn, and is possible in exclusively breastfed infants, in relation with the mother’s consumption of offending foods. FPIES may occur to solid foods (grains like rice or oat, meats, fish, egg, and vegetables). When starting during infancy, FPIES has a good prognosis and disappears grossly at 2 years of age. FPIES to fish or shellfish is more frequent in older children and adults and is long lasting. International consensus guidelines for the diagnosis and management of FPIES have been published recently. FPIAP starts in the first few months of life and is typically manifested with rectal bleeding in well-appearing breastfed infants during the first months of life in reaction to cow’s milk consumed by the mother. The condition is transient but represents one of the major causes of colitis during infancy.

Food Sensitivities: Fact Versus Fiction

Food allergies are on the rise, for reasons that are not fully understood. However, there is a tendency to overestimate their frequency, mostly based on parents' reports or on the assumption that a positive skin or blood IgE test implies the existence of clinically relevant allergy. It is imperative to base food allergy diagnosis on well-defined criteria, avoiding "alternative" tests that are available to the general public. Non-celiac gluten sensitivity is a misnomer and should be abandoned in favor of non-celiac wheat intolerance, an entity suffering from lack of biomarkers and still not convincingly described in children.

Cow's Milk Protein Allergy in Infancy: A Risk Factor for Functional Gastrointestinal Disorders in Children?

The role and prevalence of cow's milk protein allergy (CMA) in functional gastrointestinal disorders remains unclear. The aim of this review is to update knowledge on the relationship between CMA and functional abdominal pain disorders (FAPDs) in children. Cochrane Database and Pubmed were searched from inception using general and specific terms for CMA and functional gastrointestinal disorders. CMA is reported as a predisposing or coexisting factor in a wide range of functional gastrointestinal disorders in infants and children. Pathogenesis of both conditions is complex and multiple mechanisms including dysmotility and hypersensitivity might contribute to the clinical manifestations. Data supporting the possible role of food allergies in the pathogenesis of FAPDs are limited. CMA may predispose to early life inflammation and visceral hypersensitivity, which in turn might manifest as FAPDs. The diagnosis of either CMA or FAPDs and distinction between them is challenging because of nonspecific and overlapping symptoms. Lack of accurate allergy tests in non-IgE (immunoglobulin E) mediated cases is also problematic. Oral food challenge, following an elimination diet, should be performed to diagnose a suspected non-IgE CMA allergy in children with FAPDs. In the management of FAPDs, an elimination diet should be considered for a limited period to verify if the symptoms improve or resolve.

Microbiota and Derived Parameters in Fecal Samples of Infants with Non-IgE Cow's Milk Protein Allergy under a Restricted Diet

Cow’s milk protein allergy (CMPA) is the most common food allergy in infancy. Non-IgE mediated (NIM) forms are little studied and the responsible mechanisms of tolerance acquisition remain obscure. Our aim was to study the intestinal microbiota and related parameters in the fecal samples of infants with NIM-CMPA, to establish potential links between type of formula substitutes, microbiota, and desensitization. Seventeen infants between one and two years old, diagnosed with NIM-CMPA, were recruited. They were all on an exclusion diet for six months, consuming different therapeutic protein hydrolysates. After this period, stool samples were obtained and tolerance development was evaluated by oral challenges. A control group of 10 age-matched healthy infants on an unrestricted diet were included in the study. Microbiota composition, short-chain fatty acids, calprotectin, and transforming growth factor (TGF)-β₁ levels were determined in fecal samples from both groups. Infants with NIM-CMPA that consumed vegetable protein-based formulas presented microbiota colonization patterns different from those fed with an extensively hydrolyzed formula. Differences in microbiota composition and fecal parameters between NIM-CMPA and healthy infants were observed. Non-allergic infants showed a significantly higher proportion of Bacteroides compared to infants with NIM-CMPA. The type of protein hydrolysate was found to determine gut microbiota colonization and influence food allergy resolution in NIM-CMPA cases.

Food Protein-Induced Enterocolitis Instead of Necrotizing Enterocolitis? A Neonatal Intensive Care Unit Case Series

Necrotizing enterocolitis is an important disease in infants born premature. However, other disease entities present with similar signs and symptoms. This series reviews 5 atypical cases initially diagnosed as necrotizing enterocolitis that may be more consistent with food protein-induced enterocolitis. Food protein-induced enterocolitis may be underdiagnosed in this population.

Is food protein induced enterocolitis syndrome only a non IgE-mediated food allergy?

Food protein induced enterocolitis syndrome (FPIES) is classified as non-IgE-mediated or cell-mediated food allergy, although there is an atypical phenotype so defined for the presence of specific IgEs. All diagnostic criteria for FPIES include the absence of skin or respiratory symptoms of IgE-mediated type. We present four cases that suggest that specific IgEs may have a pathogenic role, resulting in the existence of different FPIES phenotypes. This could be important from a diagnostic and therapeutic point of view.

Food protein-induced enterocolitis syndrome by fish: Not necessarily a restricted diet

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food hypersensitivity usually due to cow's milk or soy. Recent researches show that fish is 1 of the most important triggers of FPIES in the Mediterranean countries. Due to the risk of multiple-food FPIES, avoiding foods in the same category or that often occur together may be reasonable. The aim of this study was to evaluate the evolution and follow-up of FPIES related to fish over a period of 20 years. We describe the clinical features of our population, discuss different approaches to oral food challenges, and analyze the possibility of introducing the culprit fish or other nonrelated fish to avoid unnecessary restricted diets.

Breast-feeding regulates immune system development via transforming growth factor-β in mice pups

BACKGROUND

Breast milk contains important nutrients and immunoregulatory factors that are essential for newborn infants. Recently, epidemiological studies suggested that breast-feeding prevents a wide range of infectious diseases and lowers the incidence of infant allergic diseases.

METHODS

To examine the effects of breast milk on immunological development in infancy, we established an artificial rearing system for hand-feeding mice and compared mouse pups fed with either breast milk or milk substitute. All mice were killed at 14 days of age and immune cells in the thymus, spleen, and small intestine were examined on flow cytometry.

RESULTS

The number of thymocytes was higher whereas that of total immune cells of peripheral lymphoid tissues was lower in mice fed breast milk compared with milk substitute-fed mice. In peripheral lymphoid tissues, the proportion of B cells was higher and that of CD8+ T cells, macrophages, dendritic cells, and granulocytes was significantly lower in breast milk-fed mice. The same alteration in immune cells of the thymus and peripheral lymphoid tissues in milk substitute-fed mice was also observed in pups reared by mother mice treated with anti-transforming growth factor-β (anti-TGF-β) monoclonal antibody.

CONCLUSIONS

Breast milk regulates the differentiation and expansion of innate and adaptive immune cells partly due to TGF-β. Hence, TGF-β in breast milk may be a new therapeutic target for innate immune system-mediated diseases of infancy.

Food protein-induced enterocolitis syndrome: a challenging diagnosis

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food hypersensitivity triggered by food proteins. It may present acutely, with repetitive vomiting, diarrhoea and lethargy leading to dehydration and eventually shock or insidiously with intermittent emesis, chronic diarrhoea or failure to thrive. We describe a paediatric male patient with recurrent sepsis-like episodes of fever, lethargy, ashen-grey skin colouration and vomiting followed by diarrhoea. These episodes were triggered by cow's milk formula and grains. Laboratory tests revealed leucocytosis, thrombocytosis, metabolic acidosis and elevated C reactive protein. After exclusion of other differential diagnoses, the diagnosis of FPIES was established on clinical improvement with withdrawal of the offending food and positive oral food challenge. FPIES diagnosis requires a high index of suspicion and is frequently delayed, which contributes to an increased morbidity. This is due to the wide spectrum of clinical presentations and due to the absence of specific diagnostic tests.

Non-IgE-mediated gastrointestinal food allergies

PURPOSE OF REVIEW

We focus on recent advances regarding the epidemiology, physiopathology, diagnosis and managements of non-IgE-mediated gastrointestinal food allergies (non-IgE-GI-FAs), particularly food protein-induced enterocolitis syndrome (FPIES).

RECENT FINDINGS

The first international FPIES diagnostic and management guidelines have been recently published. Although FPIES largely remains a diagnosis of exclusion, it may be more prevalent than previously thought. Ondansetron has emerged as a major tool for the treatment of FPIES acute reactions. Recent data also suggest an important role for innate immune cells in FPIES pathogenesis.

SUMMARY

Despite major advances in the diagnosis and management of non-IgE-GI-FAs, particularly FPIES, the lack of specific diagnostic tests and biomarkers to guide clinical management remains challenging.

A systematic review of food protein-induced enterocolitis syndrome from the last 40 years

OBJECTIVE

To provide a complete, exhaustive summary of current literature relevant to food protein-induced enterocolitis syndrome (FPIES).

DATA SOURCES

Data have been extracted from PubMed and Science Direct databases.

STUDY SELECTIONS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, a literature search for peer-reviewed journal articles in English through January 1975 with updates through October 2016 was conducted. Relevant publications were reviewed that included pediatric and adult populations. Information on the study design, sample, intervention, comparators, outcome, timeframe, and risk of bias were abstracted for each article.

RESULTS

Of 135 reviewed reports, 52 were included in this systematic review. In accordance with the age at onset, clinical features, and offending foods, it is possible to distiguish different types of FPIES. An immune systemic involvement can occur in patients with FPIES. In addition to the most common causative foods (cow's milk, soy, and rice), any food can potentially cause FPIES. Although specific diagnostic tests are not available, open food challenge remains the gold standard for FPIES diagnosis. Moreover, because of the lack of randomized clinical trials and of use of different adopted methods, confounding factors might mask critical findings, leading to poor knowledge of this pleiotropic clinical entity.

CONCLUSION

Multicenter studies are needed to better develop an evidence-based approach to pathophysiology, prevalence, diagnosis, and natural history of the disease.

Food protein-induced enterocolitis syndrome - a review of the literature with focus on clinical management

Food protein-induced enterocolitis syndrome (FPIES) is a potentially severe presentation of non-IgE-mediated gastrointestinal food allergy (non-IgE-GI-FA) with heterogeneous clinical manifestations. Acute FPIES is typically characterized by profuse vomiting and lethargy, occurring classically 1-4 hours after ingestion of the offending food. When continuously exposed to the incriminated food, a chronic form has been described with persistent vomiting, diarrhea, and/or failure to thrive. Although affecting mainly infants, FPIES has also been described in adults. Although FPIES is actually one of the most actively studied non-IgE-GI-FAs, epidemiologic data are lacking, and estimation of the prevalence is based on a limited number of prospective studies. The exact pathomechanisms of FPIES remain not well defined, but recent data suggest involvement of neutrophils and mast cells, in addition to T cells. There is a wide range of food allergens that can cause FPIES with some geographical variations. The most frequently incriminated foods are cow milk, soy, and grains in Europe and USA. Furthermore, FPIES can be induced by foods usually considered as hypoallergenic, such as chicken, potatoes or rice. The diagnosis relies currently on typical clinical manifestations, resolving after the elimination of the offending food from the infant's/child's diet and/or an oral food challenge (OFC). The prognosis is usually favorable, with the vast majority of the case resolving before 5 years of age. Usually, assessment of tolerance acquisition by OFC is proposed every 12-18 months. Of note, a switch to an IgE-mediated FA is possible and has been suggested to be associated with a more severe phenotype. Avoiding the offending food requires education of the family of the affected child. A multidisciplinary approach including ideally allergists, gastroenterologists, dieticians, specialized nurses, and caregivers is often useful to optimize the management of these patients, that might be difficult.

DMP1-CDG (CDG1e) with Significant Gastrointestinal Manifestations; Phenotype and Genotype Expansion

The literature describes eight cases of mutations in the DPM1 gene generating DMP1-CDG, causing similar phenotype of early onset seizures, microcephaly and developmental delay. Investigations of these patients revealed associated abnormal findings on brain imaging, elevated CK, abnormal clotting factors and mildly deranged serum transaminases. We describe the ninth case of DMP1-CDG, whose clinical presentation includes severe gastrointestinal involvement, i.e. food protein induced enterocolitis syndrome (FPIES). Gastrointestinal manifestations (GIT) of the congenital glycosylation disorders have included deranged liver function, hepatomegaly, liver fibrosis, steatosis and protein-losing enteropathy. This is the first report of a congenital glycosylation disorder being associated with FPIES.

Clinical and immunological characteristics of a pediatric population with food protein-induced enterocolitis syndrome (FPIES) to fish

BACKGROUND

Food protein-induced enterocolitis (FPIES) is an uncommon, non-IgE-mediated food allergy that usually debuts in infancy with profuse vomiting, lethargy, and pallor 2-4 h following ingestion of the offending food. Its immune mechanism is not known. We aimed to describe the clinical features and outcome of children with fish-FPIES as well as to investigate on cellular immune response implicated.

METHODS

Prospective and follow-up clinical study of children with FPIES by fish over a period between 2004 and 2013 was conducted. Measurement in vitro of both cytokine production in peripheral blood mononuclear cells (PBMCs) and expression of HLA-DR in monocyte-derived dendritic cells stimulated with fish extracts.

RESULTS

Sixteen children (seven male and nine female) were included, with a mean age of onset at 10 months. Diagnosis was established after a median of 4 reactions. Twelve patients were treated in emergency room, and two were admitted in intensive care. Patch tests were positive in six patients. Skin prick tests (SPTs) and specific IgE to all fish tested were negative. Only three children reached tolerance at a mean age of 4.5 years. Eight children avoided fish because of positive oral food challenge (OFC) after 6 years of age. Other patients have not been challenged because of parent refusal to OFC or a recent diagnosis. TNF-α was increased in patients, and a significant elevation of the HLA-DR marker was also observed in these patients vs. control donors.

CONCLUSIONS

FPIES caused by fish in many cases presents with severe clinical manifestations. Patch test has poor diagnostic value, and OFC is the gold standard to test tolerance. The cytokine TNF-α may be implicated in the clinical symptoms. Higher expression of HLA-DR in dendritic cells has also been detected in our patients.

FPIES: Reviewing the Management of Food Protein-Induced Enterocolitis Syndrome

Purpose of Review. The aim of this review is to provide a case driven presentation of the presenting features and diagnostic criteria particularly focusing on the management of FPIES. It also summarises the natural history and resolution of cow's milk induced FPIES. Data Sources. OvidSP Database was used to search for literature using the keywords food protein-induced enterocolitis and FPIES. Recent Findings. The diagnosis of FPIES is often delayed following two or more presentations. Symptoms in the acute form include profuse vomiting usually 2–6 hours following ingestion of food. Vomiting may or may not be accompanied by diarrhoea. Management involves removing the causal food protein from diet. There is some concomitance in cow's milk and soya induced FPIES. Hence extensively hydrolysed formula is the milk of choice unless breast-feeding is carried out in which case that should be continued. Summary. FPIES is a complex form of non-IgE mediated food allergy. More awareness and knowledge of the condition are required to prevent misdiagnosis. Early diagnosis and removal of the culprit food protein improve the outcome. Good nutritional advice and clear management plans are important. More multicentre studies are required to reevaluate and produce consistent oral food challenge criteria and guidelines.

Diagnosis of Food Allergy

The prevalence of food allergies has been on the increase over the last 2 decades. Diagnosing food allergies can be complicated, as there are multiple types that have distinct clinical and immunologic features. Food allergies are broadly classified into immunoglobulin E (IgE)-mediated, non-IgE-mediated, or mixed food allergic reactions. This review focuses on the clinical manifestations of the different categories of food allergies and the different tests available to guide the clinician toward an accurate diagnosis.

Food Protein-Induced Enterocolitis Syndrome, Allergic Proctocolitis, and Enteropathy

Food protein-induced enterocolitis (FPIES), allergic proctocolitis (FPIAP), and enteropathy (FPE) are among a number of immune-mediated reactions to food that are thought to occur primarily via non-IgE-mediated pathways. All three are typically present in infancy and are triggered most commonly by cow's milk protein. The usual presenting features are vomiting with lethargy and dehydration in FPIES; bloody and mucous stools in FPIAP; and diarrhea with malabsorption and failure to thrive in FPE. Diagnosis is based on convincing history and resolution of symptoms with food avoidance; confirmatory diagnostic testing other than food challenge is lacking. The mainstay of management is avoidance of the suspected inciting food, with interval challenge to assess for resolution, which usually occurs in the first years of life. Studies published in the past few years clarify common presenting features, report additional culprit foods, address potential biomarkers, and suggest new management strategies.

Non-IgE-mediated gastrointestinal food allergy

Non-IgE-mediated gastrointestinal food-induced allergic disorders (non-IgE-GI-FAs) account for an unknown proportion of food allergies and include food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), and food protein-induced enteropathy (FPE). Non-IgE-GI-FAs are separate clinical entities but have many overlapping clinical and histologic features among themselves and with eosinophilic gastroenteropathies. Over the past decade, FPIES has emerged as the most actively studied non-IgE-GI-FA, potentially because of acute and distinct clinical features. FPIAP remains among the common causes of rectal bleeding in infants, while classic infantile FPE is rarely diagnosed. The overall most common allergens are cow's milk and soy; in patients with FPIES, rice and oat are also common. The most prominent clinical features of FPIES are repetitive emesis, pallor, and lethargy; chronic FPIES can lead to failure to thrive. FPIAP manifests with bloody stools in well-appearing young breast-fed or formula-fed infants. Features of FPE are nonbloody diarrhea, malabsorption, protein-losing enteropathy, hypoalbuminemia, and failure to thrive. Non-IgE-GI-FAs have a favorable prognosis; the majority resolve by 1 year in patients with FPIAP, 1 to 3 years in patients with FPE, and 1 to 5 years in patients with FPIES, with significant differences regarding specific foods. There is an urgent need to better define the natural history of FPIES and the pathophysiology of non-IgE-GI-FAs to develop biomarkers and novel therapies.

Food protein-induced enterocolitis syndrome and allergic proctocolitis

Non-IgE-mediated food allergic disorders account for up to 40% of milk protein allergy in infants and young children. We aim to review the recent literature and to provide an update on diagnosis and management of food protein-induced enterocolitis syndrome (FPIES) and food protein-induced allergic proctocolitis (FPIAP). The peer-reviewed articles indexed in PubMed have been reviewed. FPIES manifests in infants as profuse, repetitive vomiting and lethargy, often with diarrhea, leading to acute dehydration, or weight loss and failure to thrive, in chronic form. FPIES is caused most commonly by cow's milk (CM) and soy proteins; rice, oat, and other solid foods may also trigger FPIES. FPIES rarely occurs in the exclusively breastfed infants. FPIES is underrecognized; children are often mismanaged as having acute viral gastrointestinal illness, sepsis, or surgical disease, delaying diagnosis of FPIES for many months. Approximately 25% of children with FPIES develop food-specific IgE antibodies and some transition to immediate food allergy; IgE positivity is associated with a more protracted course. FPIES is a self-limiting condition, with most cases resolving by age three to five years. Ondansetron may be helpful in managing acute FPIES. FPIAP is a benign condition of bloody stools in a well-appearing infant, with usual onset between one and four weeks of age. Up to 60% of cases occur in exclusively breastfed infants and resolve with maternal elimination of CM and soy proteins. The majority of cases resolve by age 12 months. FPIES may transition to IgE-mediated food allergy in some patients; IgE positivity to the FPIES food is a marker of a more persistent disease. FPIAP is benign and resolves by age 12 months in most patients.

Clinical manifestations of food protein-induced enterocolitis syndrome

PURPOSE OF REVIEW

To raise awareness among healthcare providers about the clinical and laboratory findings in acute and chronic food protein-induced enterocolitis syndrome (FPIES).

RECENT FINDINGS

FPIES can be caused by trivial exposure or rare foods.

SUMMARY

FPIES is a non-IgE-mediated reaction that usually presents with acute severe repetitive vomiting and diarrhea associated with lethargy, pallor, dehydration, and even hypovolemic shock. Manifestations resolve usually within 24-48 h of elimination of the causative food. In chronic cases, symptoms may include persistent diarrhea, poor weight gain, failure to thrive, and improvement may take several days after the food elimination. In the acute cases, laboratory evaluation may reveal thrombocytosis and neutrophilia, peaking about 6 h postingestion. Depending on the severity, metabolic acidosis and methemoglobinemia may occur. In chronic cases, anemia, hypoalbuminemia and eosinophilia may be seen. Radiologic evaluation or other procedures, such as endoscopy and gastric juice analysis may show nonspecific abnormal findings. The diagnosis is based on clinical manifestations. Further studies looking at the phenotypes of FPIES are needed to identify clinical subtypes, and to understand the predisposing factors for developing FPIES compared with immediate-type, IgE-mediated gastroenteropathies.

Definition, etiology, and diagnosis of food protein-induced enterocolitis syndrome

PURPOSE OF REVIEW

Food protein-induced enterocolitis syndrome (FPIES) is a poorly understood non-IgE-mediated food hypersensitivity, primarily affecting infants and toddlers. There are few data regarding pathophysiology of FPIES that suggest local intestinal imbalance between TNF-α and TGF-β. Patients frequently present with multiple reactions, which are characterized by projectile, repetitive emesis, dehydration, lethargy, and failure to thrive. Despite the severity of presentation, the diagnosis is frequently delayed, and patients often undergo extensive and invasive evaluation prior to reaching the diagnosis.

RECENT FINDINGS

Reviews published in the last year provide a general approach to diagnosis and management of FPIES and aim to increase awareness and understanding of FPIES among general pediatricians.

SUMMARY

Multicenter studies are necessary to reevaluate and modify the oral food challenge criteria. Research on the pathophysiology of FPIES reactions is necessary to provide insight into the evidence-based approach to diagnosis and management of FPIES. Registries are needed to understand the phenotype, triggers, and prevalence of FPIES.

Clinical management of food protein-induced enterocolitis syndrome

PURPOSE OF REVIEW

The article discusses the clinical management of patients affected by food protein-induced enterocolitis syndrome (FPIES), focusing on established therapeutic choices and future options.

RECENT FINDINGS

After FPIES has been diagnosed and avoidance of the culprit food prescribed, the most important management needs are as follows. First, recurrence of acute FPIES episodes due to accidental ingestion of culprit food. It may be useful to give patients' families an action plan. The principal suggested treatments are intravenous fluids and steroids, whereas the use of epinephrine and ondansetron requires further study. In mild-to-moderate cases, oral rehydration should be sufficient. Second, dietary introduction of at-risk foods. In children with FPIES, in addition to that/those identified as culprit(s), some foods may not be tolerated (typically cow's milk, legumes, cereals, poultry). It has been suggested to avoid introducing these foods during the baby's first year. Otherwise, they may be given for the first time in hospital, performing an oral food challenge. Third, acquisition of tolerance. Children affected by cow's milk-FPIES have a good chance of acquiring tolerance by the time they reach age 18-24 months. For other culprit foods, insufficient data are available to indicate the appropriate time, so that it is suggested that an oral food challenge be performed about 1  year after the last acute episode.

SUMMARY

Future clinical management of FPIES must take into account, among other factors, improved understanding of pathogenesis, possible detection of different phenotypes, and the introduction of more effective therapies for acute episodes. These factors will undoubtedly influence management decisions, which will become more diversified and effective.

Food protein-induced enterocolitis syndrome to trivial oral mucosal contact

Food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobulin E (IgE)-mediated gastrointestinal food hypersensitivity, mostly in infants. Patients usually present very ill and often misdiagnosed as acute gastroenteritis, sepsis, ileus, metabolic disorders, necrotizing enterocolitis, or severe gastroesophageal reflux disease. We present a case of an infant who had three acute FPIES episodes: the first was at 5 months of age after chewing on a cellophane wrapper, the second was due to sweet potato, and the third was due to rice cereal. It was realized that in the first episode, the wrapper was covering a rice cake. Evaluation at 7 months of age, while asymptomatic, showed normal complete blood count, low serum immunoglobulin E level, and negative allergy skin prick tests, indicating non-IgE sensitivity. Conclusion This case of FPIES has peculiar features in that it occurred in an exclusively breastfed infant and by non-ingestant oral contact with a trivial quantity of rice allergen.

Food protein-induced enterocolitis syndrome: pitfalls in the diagnosis

Food protein-induced enterocolitis syndrome (FPIES) represents the severe end of the spectrum of gastrointestinal food hypersensitivity; its acute episodes can culminate in severe dehydration and hypovolemic shock, and its chronic form entails considerable morbidity associated with feeding difficulty and failure to thrive. Nevertheless, awareness for this syndrome remains rather low. Many factors hamper the establishment of FPIES diagnosis. Such factors pertain to the pathophysiological mechanism of the syndrome, causal food proteins, clinical manifestations, diagnostic procedures, differential diagnosis considerations, and prevailing perceptions which may require critical appraisal. Throughout this review, we will present and discuss these issues and put the focus on factors that could lead to under-diagnosis of FPIES, cause numerous acute episodes, and substantially increase the diseases morbidity and financial burden. We will also address other issues that are clinically relevant to FPIES.

The role of casein-specific IgA and TGF-β in children with food protein-induced enterocolitis syndrome to milk

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a gastrointestinal hypersensitivity disorder with a poorly understood pathophysiology and no biomarkers to aid in diagnosis.

OBJECTIVE

To investigate humoral and cellular responses to casein in children with milk-FPIES, including the role of casein-specific (cs) IgA and T-cell mediated TGF-β responses.

PATIENTS AND METHODS

Thirty-one children previously diagnosed with milk-FPIES were challenged with milk. Twelve age-matched children with FPIES to other foods and 6 milk-tolerant children without a history of FPIES were used as controls. Casein-specific IgE, IgG, IgG4, and IgA were measured in serum and TGF-β levels in supernatants of casein-stimulated PBMCs.

RESULT

Twenty-six children with milk-FPIES reacted (active milk-FPIES) and five tolerated milk (milk-FPIES resolved) during food challenge. All of them had significantly lower levels of csIgG, csIgG4, and csIgA than control children (p-value<0.001). There were no TGF-β responses in supernatants of active milk-FPIES children.

CONCLUSION

Children with milk-FPIES have low levels of csIgG, csIgG4, and csIgA. In particular, children with active FPIES to cow's milk have deficient T-cell mediated TGF-β responses to casein, rendering TGF-β a promising biomarker in identifying children who are likely to experience FPIES reactions to this allergen. Prospective studies are needed to validate these findings, elucidate their role in FPIES pathophysiology, and establish the diagnostic utility of TGF-β in milk-induced FPIES.

Clinical presentation and referral characteristics of food protein-induced enterocolitis syndrome in the United Kingdom

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a pediatric non-IgE-mediated allergic reaction to foods. The diagnosis of FPIES is clinical, with children presenting typically 2 to 4 hours after ingestion of a food protein. The most striking symptoms are vomiting, lethargy, and pallor. Misdiagnosis and delay in presentation to an allergist or gastroenterologist are common.

OBJECTIVES

To investigate the pathway of patients with FPIES presenting to a specialist clinic in the United Kingdom to ascertain whether they experienced delays or misdiagnoses and to investigate their symptoms and triggers.

METHODS

All patients with FPIES presenting over a 3-year period (2010-2013) in a tertiary pediatric allergy clinic in London were analyzed retrospectively. This was performed by searching electronically for all patients with a diagnosis of FPIES and manually reviewing paper notes. Presenting symptoms and management pathways were collated.

RESULTS

Fifty-four patients were identified, with an average age of onset at 8 months. They initially presented to medical professionals other than an allergist or gastroenterologist. The most frequent presenting symptom was vomiting followed by signs suggesting shock or hypotension and diarrhea. Differential diagnoses included gastroenteritis, sepsis, and surgical abnormalities. The main eliciting foods were cow's milk, fish, egg, soy, and wheat.

CONCLUSION

In the United Kingdom, FPIES typically has its onset at 8 months. Patients experience a delay of 12 months in the diagnosis of FPIES and frequently have multiple episodes and interim diagnoses. A great need remains for enhanced education of medical practitioners dealing with children about the varied presentations of FPIES.