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

Clinical Presentation and Nutrition Management of Non-IgE-Mediated Food Allergy in Children

Non-IgE-mediated food allergy encompasses a wide spectrum of allergic disorders ranging from mild to severe presentations, including food protein-induced allergic proctocolitis, food protein-induced enterocolitis syndrome, and food protein-induced enteropathy. Other gastrointestinal symptoms such as constipation and gastroesophageal reflux disease have not previously been recognised as symptoms of non-IgE-mediated food allergy in food allergy guideline publications. Recently, two new consensus documents from the European Academy of Allergy, Asthma and Immunology address a potential role of food allergens in these disorders, where standard treatment has failed, and provide guidance for diagnosis and management of these conditions. Additional updates include the World Allergy Organisation guidance on the diagnosis and management of cow's milk allergy, the most commonly implicated food in non-IgE-mediated food allergy. These documents all help practitioners to distinguish between common manifestations in infancy that are not pathologic and non-IgE-mediated food allergy. Understanding diagnostic criteria is vital to prevent overdiagnosis, limit unnecessary elimination diets and preserve breastfeeding. Conversely, proper diagnosis may reduce symptoms in infants who are affected. Therefore, the first step in management of non-IgE-mediated food allergy is establishing a correct diagnosis, which requires understanding the clinical presentations and if needed, applying an appropriate short-term diagnostic elimination diet to observe for symptom resolution, followed by food reintroduction to assess for symptom recurrence. Once diagnosed, treatment requires removal of the trigger food, most commonly cow's milk, which is not without burden and nutrition risk. Non-IgE-mediated food allergies typically resolve early in childhood with some disorders resolving in infancy therefore early reassessment for tolerance is vital. Management of non-IgE-mediated food allergy entails following diagnostic algorithms, developing an individualised dietary plan, and timely assessment of tolerance development to reduce burden and nutrition risk.

Non-immunoglobulin E-mediated food allergy

Non-immunoglobulin E (IgE)-mediated food allergies are characterized by delayed gastrointestinal (GI) manifestations that occur after exposure to an inciting food protein; they include food protein-induced allergic proctocolitis (FPIAP), food protein-induced enteropathy (FPE), and food protein-induced enterocolitis syndrome (FPIES). Although the exact mechanisms underlying these disorders are not well understood, non-IgE-mediated food allergies likely represent a spectrum of disease with shared pathophysiological processes. Typically, these non-IgE-mediated food allergies begin in infancy or early childhood, although FPIES can present across the lifespan, with increasing reports in adults in recent years. Diagnosing non-IgE-mediated food allergies can be challenging due to the lack of noninvasive confirmatory tests or biomarkers for most of these disorders and the non-specific nature of GI symptoms. Thus, the diagnosis is usually made clinically, and relies on a constellation of typical symptoms that improve upon removal of the culprit food. The primary approach to management of FPIAP, FPE and FPIES is avoidance of the triggering food, and a multidisciplinary management approach that includes allergy/immunology may be required to avoid unnecessary food restriction and guide food reintroduction. This review outlines the clinical manifestations, epidemiology, pathophysiology, diagnosis, management, and prognosis of these non-IgE-mediated food allergies.

Duration of food protein-induced allergic proctocolitis (FPIAP) and the role of intestinal microbiota

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is the leading cause of rectal bleeding in infants. Tolerance is presumed to develop until the first year of age, although natural history studies are scarce, making the determination of the ideal duration for any intervention, challenging. Intestinal microbiota (IM) is crucial in food allergy development; however, data for FPIAP remain limited. This study aimed to assess FPIAP remission after 3 months of milk avoidance and its correlation with IM longitudinal changes.

METHODS

A prospective observational study of infants aged ≤6 months with a diagnosis of FPIAP. After 3 months of management according to a clinical algorithm, infants were subjected to a milk challenge using either a cow (CM) or a goat (GM) milk formula in a random order. Stool samples were collected longitudinally for microbiome analysis.

RESULTS

Out of 61 infants, 57 were challenged (29 with CM, 28 with GM). Of these, 55 (96.5%) achieved tolerance, with no difference in tolerance rates between CM (28/29) and GM (27/28). The average age of tolerance development was 6.3 months. Enterobacteriaceae clusters (Klebsiella- and Shigella-dominated) were most often represented in samples from symptomatic infants. In contrast, Bacteroides and Bifidobacteria clusters emerged later, in apparently healthy infants.

CONCLUSION

A 3-month intervention was sufficient for almost all infants to achieve tolerance. GM was tolerated equally well to CM. Symptomatic FPIAP is associated with immature enterotypes, while disease remission coincides with microbiome changes in time.

L'allergie aux protéines du lait de vache chez les nourrissons et les enfants

L'allergie aux protéines du lait de vache (APLV) est une réaction à médiation immunitaire aux protéines du lait de vache, qui peut toucher de multiples systèmes organiques, y compris le tractus gastro-intestinal. Une réaction induite par les immunoglobulines E (IgE) entraîne l'apparition rapide de symptômes allergiques faciles à reconnaître. Cependant, des réactions tardives (non induites par les IgE ou les cellules) ou mixtes (induites par les IgE et les cellules) entraînent une série de symptômes qui ressemblent à d'autres affections et dont le moment d'apparition et la gravité sont très variables. Il est difficile de déterminer si les symptômes sont attribuables à une APLV à médiation immunitaire, à une réaction non immunologique au lait de vache ou à autre chose que l'exposition au lait de vache, mais il est essentiel d'y parvenir pour proposer une prise en charge efficace. Le tableau clinique de l'APLV non induite par les IgE peut varier, mais cette affection, généralement autorésolutive, disparaît entre l'âge de un et six ans. Il faut éviter les batteries de dosages des immunoglobulines G (IgG) pour déceler les intolérances alimentaires spécifiques aux antigènes qui ne reposent pas sur des données probantes, parce qu'elles peuvent entraîner un surdiagnostic de prétendues intolérances alimentaires. Le surdiagnostic d'APLV peut être responsable de la surutilisation de préparations fortement hydrolysées, ce qui a des répercussions financières importantes pour les familles. Le présent document de principes, qui traite de l'APLV non induite par les IgE ou les cellules, aide les professionnels de la santé à distinguer et reconnaître les diverses réactions au lait de vache, aborde le rôle des tests diagnostiques et fournit des recommandations de prise en charge en fonction des données probantes exemplaires.

Cow's milk protein allergy in infants and children

Cow's milk protein allergy (CMPA) is an immune-mediated reaction to cow's milk proteins, which can involve multiple organ systems including the gastrointestinal tract. Immunoglobulin E (IgE)-mediated response results in rapid onset of allergic symptoms that are easily recognizable. However, delayed (i.e., non-IgE/cell-mediated) or mixed (IgE- and cell-mediated) reactions produce a host of symptoms that overlap with other conditions and vary widely in onset and severity. Determining whether symptoms represent immune-mediated CMPA, non-immunologic reaction to cow's milk, or are unrelated to cow's milk exposure is challenging yet essential for effective management. While the clinical presentation of non-IgE-mediated CMPA can vary, this condition is usually self-limited and resolves by 1 to 6 years of age. Food antigen-specific immunoglobulin G (IgG) panels that are not evidence-based should be avoided because they can lead to overdiagnosis of presumed food intolerances. Overdiagnosis of CMPA can result in overuse of extensively hydrolyzed formulas and have significant cost implications for families. This statement focuses on delayed non-IgE/cell-mediated CMPA and assists health care providers to distinguish between and identify varied reactions to cow's milk, discusses the role of diagnostic testing, and provides management recommendations based on best evidence.

Anaphylaxis: A 2023 practice parameter update

This practice parameter update focuses on 7 areas in which there are new evidence and new recommendations. Diagnostic criteria for anaphylaxis have been revised, and patterns of anaphylaxis are defined. Measurement of serum tryptase is important for diagnosis of anaphylaxis and to identify underlying mast cell disorders. In infants and toddlers, age-specific symptoms may differ from older children and adults, patient age is not correlated with reaction severity, and anaphylaxis is unlikely to be the initial reaction to an allergen on first exposure. Different community settings for anaphylaxis require specific measures for prevention and treatment of anaphylaxis. Optimal prescribing and use of epinephrine autoinjector devices require specific counseling and training of patients and caregivers, including when and how to administer the epinephrine autoinjector and whether and when to call 911. If epinephrine is used promptly, immediate activation of emergency medical services may not be required if the patient experiences a prompt, complete, and durable response. For most medical indications, the risk of stopping or changing beta-blocker or angiotensin-converting enzyme inhibitor medication may exceed the risk of more severe anaphylaxis if the medication is continued, especially in patients with insect sting anaphylaxis. Evaluation for mastocytosis, including a bone marrow biopsy, should be considered for adult patients with severe insect sting anaphylaxis or recurrent idiopathic anaphylaxis. After perioperative anaphylaxis, repeat anesthesia may proceed in the context of shared decision-making and based on the history and results of diagnostic evaluation with skin tests or in vitro tests when available, and supervised challenge when necessary.

Perspectives on Non-IgE-Mediated Gastrointestinal Food Allergy in Pediatrics: A Review of Current Evidence and Guidelines

Food allergy is an immune-mediated disease that can result in considerable morbidity and even mortality, with a significant negative impact on patients' quality of life. It is characterized by allergic symptoms that can occur shortly after a relevant food allergen ingestion, or can be delayed or chronic, which make it more difficult for diagnosis. The symptoms of this disease can range from mild to severe, and rarely can cause anaphylaxis, a life-threatening allergic reaction. The prevalence of non-immunoglobulin E (IgE)-mediated food allergy is poorly established outside of cow's milk allergy, with an adjusted incidence ranging between 0.13% and 0.72%. Several disorders are classified as non-immunoglobulin E (IgE)-mediated food allergies that predominantly affect the gastrointestinal tract including food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), food protein-induced allergic enteropathy (FPE), and food protein-induced dysmotility disorders (GORD and constipation). Eosinophilic esophagitis (EoE) is listed in this group, even though it considered by some authorities to be mixed reaction with both IgE and cell-mediated immune response to be involved in the reaction. The most common types of non-IgE-mediated food allergy are food protein-induced enterocolitis syndrome (FPIES) and food protein-induced allergic proctocolitis (FPIAP). These disorders typically present in infancy and are often triggered by cow's milk protein. Patients with FPIES present with profuse emesis and dehydration, while FPIAP patients present with hematochezia in otherwise healthy infants. Since there are no specific confirmatory non-invasive diagnostic laboratory tests, the diagnosis is usually made clinically when typical symptoms improve upon the removal of the culprit food. Food reintroduction should be attempted, when possible, with documentation of symptoms of relapse to confirm the diagnosis. The management includes dietary avoidance, supportive treatment in the case of accidental exposure, and nutritional counseling. This review focuses on the clinical manifestations, epidemiology, management, and recent guidelines of the most common non-IgE-mediated food hypersensitivity disorders (FPIES, FPIAP, and FPE).

Complementary food introduction practices in infants with intestinal failure

BACKGROUND

Oral intake in infants with intestinal failure (IF) may be limited due to intolerance or feeding difficulties. Guidelines for the introduction of semisolid or solid complementary foods (CFs) to infants with IF do not exist. CF intake and caloric contribution from CF is difficult to assess due to malabsorption and incomplete recording. The aim of this study was to identify institutional approaches to introducing CF to infants with IF.

METHODS

The American Society for Parenteral and Enteral Nutriton (ASPEN) Pediatric Intestinal Failure Section Registered Dietitian/Nutritionist (RDN) working group designed a 10-question online cloud-based survey to assess group member practice related to the introduction of CF to infants with IF.

RESULTS

Twenty-six surveys were completed. Thirteen (50%) RDNs recommend introduction of CF between 4 and 6 months of age. Nineteen (76%) recommend adding pureed foods to gastrostomy tube feedings. Seventeen (65%) follow standard infant feeding practice guidelines with half citing the American Academy of Pediatrics. Approximately half (44%) recommend introducing vegetables first and the majority (80%) recommend delaying the introduction of fruits. The vast majority (92%) recommend specific foods to minimize stool output including green beans, bananas, infant cereals, and meats/protein.

CONCLUSION

Institutional practices related to the introduction of CF to infants with IF vary. Similarities with first food choice and foods to avoid were observed. Evidenced-based practice guidelines for the introduction of CF to infants with IF need to be established to determine best practices for reducing stool output, encouraging weaning from parenteral nutrition, and achieving enteral autonomy.

Dietary Factors May Delay Tolerance Acquisition in Food Protein-Induced Allergic Proctocolitis

BACKGROUND

Dietary and environmental factors may influence tolerance acquisition in food protein-induced allergic proctocolitis (FPIAP). This retrospective observational study explored the role of maternal diet during pregnancy and breastfeeding in tolerance acquisition in infantile FPIAP.

METHODS

Breastfed infants with FPIAP from six diverse regions in Greece were divided into two groups, based on development of tolerance to the trigger food: Group A (n = 43), before, and Group B (n = 53), after, the 6th month of age. Maternal diet during pregnancy and breastfeeding was elicited using the Mediterranean Diet Score Questionnaire and the Mediterranean Oriented Culture Specific Semi-Quantitative Food Frequency Questionnaire.

RESULTS

Mean age at diagnosis of FPIAP (1.5 months) and weaning (5.5 months) were the same in both groups. The main trigger was cow's milk. Group A received infant milk formula earlier than Group B. Group B had a higher incidence of asthma/wheeze, siblings with milk allergy, maternal smoking and rural residence. On multivariate analysis, earlier resolution of FPIAP was associated with higher maternal education and with salt intake and consumption of goat/sheep cheese during pregnancy and olive oil during breastfeeding. Consumption of multivitamins during pregnancy and meat, winter fruits, green vegetables, butter, salt, "ready-to-eat" meals and pastries during breastfeeding were correlated with longer duration of symptoms.

CONCLUSIONS

Mothers of children with FPIAP to cow's milk protein can be advised to eat more yogurt, cheese and olive oil during subsequent pregnancies, and avoid multivitamins, grilled food, "ready-to-eat" meals, pastries, meat and alcohol during breastfeeding, to reduce the duration of FPIAP presenting in future infants.

Children with Delayed-Type Cow's Milk Protein Allergy May Be at a Significant Risk of Developing Immediate Allergic Reactions Upon Re-introduction

Background

Cow's Milk Protein Allergy (CMPA) is the most common food allergy in children. The reaction is classified into IgE-mediated immediate reaction and delayed-onset, according to the underlying immune mechanism, and hence, the timing of the symptoms. Case reports suggest that children, with delayed CMPA reactions on elimination diet, may develop severe immediate reactions on reintroduction.

Aim

The objective of this study was to evaluate the incidence and the risk factors of developing immediate reactions to milk and dairy products in children with CMPA whose initial presentations were of delayed type.

Methods

A retrospective chart review of children, aged 0-12 years, presented with delayed type CMPA reactions to the allergy-clinical immunology clinics, was performed. The diagnosis was made clinically, and with appropriate allergy tests when indicated.

Results

Sixty children were included. Males:female ratio was 1.7:1. Family history of atopy was in 72%, and 57% had personal history of atopy. Sixty percent were not breast fed. The most common concomitant food allergy was egg. The most common initial presentation was diarrhea without protein loss or bleeding followed by exacerbation of atopic dermatitis upon exposure to dairy products. Immediate reactions developed in 21.6% upon re-exposure. There were significant associations with concomitant food allergy (OR 56.6 (3.15-1016.1) P<0.0001), especially eggs (OR 12.85 (3.09-53.5) P<0.01).

Conclusion

Children with CMPA, who present with delayed-type allergic reactions, may be at a significant risk of developing immediate reactions upon reintroduction. Evaluation of possible IgE-mediated allergic reactions before reintroduction may be advisable.

Assessment of intracellular zinc levels in infants with food protein-induced allergic proctocolitis

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is characterized by bloody stools in well-appearing infants. Zinc is a micronutrient that plays a crucial role in immune modulation and is essential for cellular function during immune response. Although there are studies on the assessment of intracellular zinc levels in allergic diseases, no data is available on erythrocyte zinc levels of patients with FPIAP.

OBJECTIVE

This study aimed to assess the erythrocyte zinc levels of children with allergic proctocolitis and compare zinc levels with clinical and demographic characteristics.

METHODS

This was a case-control study that prospectively compared 50 patients with FPIAP and 50 healthy children without malnutrition. The erythrocyte zinc levels of children were determined using atomic absorption spectrophotometry.

RESULTS

Fifty patients with FPIAP, including 28 (51%) girls, with median age of 7.1 ± 2.9 (3-14) months and 50 healthy children, including 26 (53.1%) girls, with median age of 7.7 ± 2.8 (3-13) months were included in the study. Seventy percent (n = 35) of the patients with FPIAP started to have symptoms while they were exclusively breastfeeding. Offending allergen foods were cow's milk (78%), egg (40%), sesame (10%), hazelnut (8%), almond (6%), beef (6%), and peanuts (6%, n = 3). Intracellular (erythrocyte) zinc levels in patients with FPIAP were lower than in the healthy control group (495.5 ± 134 µg/dL, 567.3 ± 154.4 µg/dL, respectively, P = 0.01). Patients with FPIAP aged younger than 6 months had lower intracellular zinc levels compared with those aged above 6 months (457 ± 137 µg/dL; 548 ± 112 µg/dL, respectively, P = 0.01). There was no relationship between zinc levels and time of symptom onset, presence of concomitant disease, being allergic to multiple foods, and family history of atopy (P > 0.05).

CONCLUSIONS

FPIAP is a food allergy with limited information on its pathogenesis. Considering the beneficial effects on gastrointestinal system epithelia, zinc may be involved in the pathogenesis of FPIAP. Future comprehensive prospective research on this subject is of importance.

Alterations of the gut microbiota and short chain fatty acids in necrotizing enterocolitis and food protein-induced allergic protocolitis infants: A prospective cohort study

Background

Even though presenting with similar clinical manifestations, necrotizing enterocolitis (NEC) and food protein-induced allergic protocolitis (FPIAP) have completely different treatments and prognosis. Our study aimed to quantify and evaluate differences in gut microbiota and short chain fatty acids (SCFAs) between infants with NEC and FPIAP to better identify these two diseases in clinical settings.

Methods

A total of 43 infants with NEC or FPIAP in Children's Hospital of Chongqing Medical University, China between December 2020 and December 2021 were enrolled. Stool samples were prospectively collected and froze. Infants defined as NEC were those who presented with clinical courses consistent with NEC and whose radiographs fulfilled criteria for Bell's stage 2 or 3 NEC, while those who were healthy in appearance and had blood in the stool (visible or may be microscopic), had normal bowel sounds in physical examination, were resolved after eliminating the causative food, and/or had recurrence of symptoms after oral food challenge (OFC) were defined as FPIAP. Primers specific for bacterial 16S rRNA genes were used to amplify and pyrosequence fecal DNA from stool samples. Gas chromatography-mass spectrometry (GC-MS) technology was used to determine the concentrations of SCFAs.

Results

Among the 43 infants, 22 were diagnosed with NEC and 21 were diagnosed with FPIAP. The microbial community structure in NEC infant stools differed significantly from those in FPIAP infant stools. NEC infants had significantly higher proportion of Actinobacteria and reduced proportion of Bacteroidetes compared with FPIAP infants, and the proportions of Halomonas, Acinetobacter, Bifidobacterium, and Stenotrophomonas in NEC infants were significantly higher than that of FPIAP infants. In addition, infants with NEC had significantly lower levels of acetic acid, propionic acid, butyric acid, isovaleric acid, and total SCFAs, and higher level of hexanoic acid as compared to the infants of the FPIAP group.

Conclusions

The differences of gut microbiota composition and concentrations of SCFAs might represent suitable biomarker targets for early identification of NEC and FPIAP.

Cow’s milk-induced gastrointestinal disorders: From infancy to adulthood

Milk is related to many gastrointestinal disorders from the cradle to the grave due to the many milk ingredients that can trigger gastrointestinal discomfort and disorders. Cow’s milk protein allergy (CMPA) is the most common food allergy, especially in infancy and childhood, which may persist into adulthood. There are three main types of CMPA; immunoglobulin E (IgE)-mediated CMPA, non-IgE-mediated CMPA, and mixed type. CMPA appears before the first birthday in almost all cases. Symptoms may start even during the neonatal period and can be severe enough to simulate neonatal sepsis. CMPA (often non-IgE mediated) can present with symptoms of gastroesophageal reflux, eosinophilic esophagitis, hemorrhagic gastritis, food protein-induced protein-losing enteropathy, and food protein-induced enterocolitis syndrome. Most CMPAs are benign and outgrown during childhood. CMPA is not as common in adults as in children, but when present, it is usually severe with a protracted course. Lactose intolerance is a prevalent condition characterized by the development of many symptoms related to the consumption of foods containing lactose. Lactose intolerance has four typical types: Developmental, congenital, primary, and secondary. Lactose intolerance and CMPA may be the underlying pathophysiologic mechanisms for many functional gastrointestinal disorders in children and adults. They are also common in inflammatory bowel diseases. Milk consumption may have preventive or promoter effects on cancer development. Milk may also become a source of microbial infection in humans, causing a wide array of diseases, and may help increase the prevalence of antimicrobial resistance. This editorial summarizes the common milk-related disorders and their symptoms from childhood to adulthood.

Detecting the Bitterness of Milk-Protein-Derived Peptides Using an Electronic Tongue

Bitterness is a considerable limiting factor for the application of bioactive peptides in the food industry. The objective of this study was to compare the level of bitterness of milk-protein-derived peptides using an electronic tongue (E-tongue). Liquid milk protein concentrate (LMPC) was prepared from ultra-heat-treated skimmed cow’s milk. It was initially hydrolyzed with different concentrations of trypsin, namely, 0.008 g·L−1, 0.016 g·L−1 and 0.032 g·L−1. In a later exercise, tryptic-hydrolyzed LMPC (LMPC-T) was further hydrolyzed using Lactobacillus bulgaricus and Streptococcus thermophilus. The effect of glucose in microbial hydrolysis was studied. The bitterness of peptides was evaluated with respect to quinine, a standard bittering agent. The level of bitterness of the peptides after microbial hydrolysis of LMPC-T (LMPC-T-F and LMPC-T-FG) was evaluated using a potentiometric E-tongue equipped with a sensor array that had seven chemically modified field-effect transistor sensors. The results of the measurements were evaluated using principal component analysis (PCA), and subsequently, a classification of the models was built using the linear discriminant analysis (LDA) method. The bitterness of peptides in LMPC-T-F and LMPC-T-FG was increased with the increase in the concentration of trypsin. The bitterness of peptides was reduced in LMPC-T-FG compared with LMPC-T-F. The potential application of the E-tongue using a standard model solution with quinine was shown to follow the bitterness of peptides.

Food protein-induced enterocolitis syndrome presenting after necrotizing enterocolitis in a preterm neonate: a case report

When bloody stools occur in a very-low-birth-weight infant in the neonatal intensive care unit (NICU), necrotizing enterocolitis (NEC) is a prime consideration, though food protein-induced enterocolitis syndrome (FPIES) can be causative and is difficult to distinguish from NEC. Food allergy is an adverse reaction following exposure to food due to an abnormal immunologic response to food, and cow's milk allergy (CMA) is the most likely form of food allergy in infants. The clinical features and proper management of patients with FPIES are important to differentiate FPIES from NEC. However, there are very few study reports of preterm infants presenting with food allergy-induced enterocolitis after NEC. Here, we report a case of a very-low-birth-weight infant born at 28 weeks of gestational age who developed recurrent episodes of bloody stools when he was fed cow's milk or given breast milk fortified with milk after NEC recovery on day of life (DOL) 29, 46, and 54. A male preterm infant born at 28 weeks of gestational age presented with bloody stools on DOL 7. He was diagnosed with early-onset NEC with abdominal tenderness, sluggish bowel sounds, increased C-reactive protein (CRP) level and pneumatosis intestinalis (PI). After recovery from NEC on DOL 20, the infant developed three recurrent episodes of bloody stools after being fed cow's milk or breast milk fortified with dairy milk. He was suspected of having recurrent episodes of NEC, but the infant was fairly healthy and did not present abdominal tenderness or abnormal bowel sounds on physical examination. Consecutive blood tests revealed normal CRP levels and increasing eosinophil levels. Abdominal radiograph revealed mild thickening of the small bowel, with no evidence of PI. The infant was finally diagnosed with FPIES in addition to NEC. After the infant received hydrolyzed formula, the bloody stool symptoms were finally resolved. Our case suggests that infants with recurrent episodes of bloody stools with increasing systemic eosinophils count should be considered for the diagnosis of FPIES with cow's milk formula. Rapid improvement and non-progression of systemic symptoms and signs after removing exposure to milk protein may differentiate FPIES from NEC.

Epidemiology of non-IgE-mediated food allergies: what can we learn from that?

PURPOSE OF REVIEW

To underline the main characteristics of the non-Immunoglobulin E (IgE)-mediated food allergies (food protein-induced allergic proctocolitis food protein-induced enteropathy and food protein-induced enterocolitis syndrome ), which are common diseases in primary care and in allergy and gastroenterology specialty practices evaluating children.

RECENT FINDINGS

Non-IgE-mediated food allergies comprise a spectrum of diseases with peculiar features affecting infants and young children. The most prominent features of these diseases are symptoms that affect mainly the gastrointestinal tract.

SUMMARY

It is of paramount importance to provide the clinicians with the tools for non-IgE-mediated food allergy recognition in clinical practice to avoid the misdiagnosis with unnecessary laboratory tests and detrimental treatments.

Gastrointestinal immunopathology of food protein-induced enterocolitis syndrome and other non-immunoglobulin E-mediated food allergic diseases

OBJECTIVE

To provide a concise summary of the current literature regarding gastrointestinal immunopathology of food protein-induced enterocolitis syndrome (FPIES) and other non-immunoglobulin E (IgE)-mediated food allergic diseases.

DATA SOURCES

Data were extracted from PubMed, MEDLINE, and ScienceDirect databases.

STUDY SELECTIONS

Original articles, review articles, and guidelines published in the past 5 years in peer-reviewed journals were first summarized. The original articles cited were then reviewed and relevant results were extracted.

RESULTS

Patients with FPIES and non-IgE-mediated food allergic diseases developed vomiting, diarrhea, and food aversion expelled food allergen from their bodies. Aside from T helper type 2 (T_H2) immunity, T_H1, T_H17, innate immunity, and epithelial mucosal barrier defect were also found to be important in the pathogenesis. Eosinophils, widely identified in the biopsy samples, were key players or were late-recruited cells for tissue repairs in those diseases. Intestinal dysbiosis and their metabolites stimulated enterochromaffin cells or enteroendocrine cells to produce serotonin, interfering with intestinal motility and subsequently affecting brain function. FPIES and non-IgE-mediated food allergic diseases were likely part of the atopic march. Allergic inflammation in intestinal mucosa might result in subsequent inflammation in the airway mucosa, suggesting the theory of "one mucosa, one disease."

CONCLUSION

The immune responses of FPIES and non-IgE-mediated food allergic diseases were not limited to the gastrointestinal tract, but also trigger wider inflammatory responses beyond it. Further research will be required to determine the systemic effect and intestinal microbiome of those diseases.

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.

Daily Dilemmas in Pediatric Gastrointestinal Pathology

The evaluation of gastrointestinal pathology in children often requires a different approach from that in adults. In this concise review, the authors outline 3 diagnostic challenges that are often encountered in daily practice; these include eosinophilic diseases, duodenal intraepithelial lymphocytosis with preserved villous architecture, and terminal ileal inflammation in the setting of idiopathic inflammatory bowel disease.

Risk Factors Influencing Tolerance and Clinical Features of Food Protein-induced Allergic Proctocolitis

OBJECTIVE

Continued progress in our understanding of the food protein-induced allergic proctocolitis (FPIAP) will provide the development of diagnostic tests and treatments. We aimed to identify precisely the clinical features and natural course of the disease in a large group of patients. Also, we investigated the predicting risk factors for persistent course since influencing parameters has not yet been established.

METHODS

Infants who were admitted with rectal bleeding and had a diagnosis of food protein-induced allergic proctocolitis in 5 different allergy or gastroenterology outpatient clinics were enrolled. Clinical features, laboratory tests, and prognosis were evaluated. Risk factors for persistent course were determined by logistic regression analyses.

RESULTS

Among the 257 infants, 50.2% (n = 129) were girls and cow's milk (99.2%) was the most common trigger. Twenty-four percent of the patients had multiple food allergies and had more common antibiotic use (41.9% vs 11.8%), atopic dermatitis (21% vs 10.2%), wheezing (11.3% vs 1.5%), colic (33.8% vs 11.2%), and IgE sensitization (50% vs 13.5%) compared to the single-food allergic group (P < 0.001, P = 0.025, P = 0.003, P < 0.001, respectively). In multivariate logistic regression analysis, presence of colic (odds ratio [OR]: 5.128, 95% confidence interval [CI]: 1.926-13.655, P = 0.001), IgE sensitization (OR: 3.964, 95% CI: 1.424-11.034, P = 0.008), and having allergy to multiple foods (OR: 3.679, 95% CI: 1.278-10.593, P = 0.001] were found to be risk factors for continuing disease after 1 year of age.

CONCLUSION

Although most children achieve tolerance at 1 year of age, IgE sensitization, allergy to multiple foods, and presence of colic were risk factors for persistent course and late tolerance. In this context, these children may require more close and extended follow-up.

A Slice of Food Protein-Induced Enterocolitis Syndrome (FPIES): Insights from 441 Children with FPIES as Provided by Caregivers in the International FPIES Association

BACKGROUND

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food allergy. There is little known about the demographic characteristics, food triggers, and risk factors for FPIES.

OBJECTIVE

To characterize the demographic characteristics, food triggers, risk factors, and management in children with FPIES.

METHODS

We retrospectively analyzed surveys completed by 410 caregiver-members of the International FPIES Association, both at a conference for families affected by FPIES and online.

RESULTS

Most of the children were female (50.7%), white (86.2%), and atopic (54.8%), with a median age of 2 years (ranging from 2 months to 19 years). The most common food groups avoided were grains (60.0%), cow's milk (52.4%), vegetables (42.7%), and fruits (38.0%). Avocado was the most commonly avoided fruit. Avoiding avocado was associated with increased likelihood of avoiding banana (P < .001). Of these children, 69.4% avoided at least 2 food groups because of FPIES, and 20.3% had a first-degree relative with FPIES. Having a first-degree relative with FPIES was associated with increased likelihood of avoiding multiple food groups (P = .035).

CONCLUSIONS

The most common food group avoided was grains, consistent with recent literature. Avocado avoidance was higher than previously reported, and this is the first report of an association between avocado and banana avoidance in FPIES. Avoiding multiple food groups because of FPIES was more common than previously reported. A large proportion of children in our cohort had first-degree relatives with FPIES, and, furthermore, having a first-degree relative with FPIES was significantly associated with the affected child avoiding multiple food groups.

Nutrition and Avoidance Diets in Children With Food Allergy

Food allergy (FA) is a significant health issue which considerably influences the quality of life of both children and their family. The increasing prevalence of FA, documented in the last 3 decades, has led to the reassessment of FA prevention strategies and particularly to giving up the approach based on delaying the introduction of potential food allergens. Several observational and interventional studies demonstrated a potential effectiveness of the early food introduction strategy in FA prevention, although strong evidence from randomized controlled trials are lacking and, sometimes, contrasting. The current approach to FA is mainly based on avoidance diet and the use of rescue medications in case of allergic reaction, although active allergen immunotherapy has recently become an increasingly important therapeutic strategy to approach IgE-mediated FA, potentially able to induce improvement through desensitization to a specific food. This review provides an overview on the historical evolution of recommendations about FA and on evidence published in the last 15 years on nutritional intervention strategy, i.e., early introduction of allergen or avoidance diet, in the prevention and management of IgE-mediated and non-IgE-mediated FA in children.

Diagnosis and management of Non-IgE gastrointestinal allergies in breastfed infants-An EAACI Position Paper

It is well-established that food proteins, such as egg, soya, cow's milk and wheat, are detectable in breastmilk for many hours or days after ingestion. Exposure to these proteins is important to the process of developing tolerance but can also sometimes elicit IgE-mediated and non-IgE-mediated allergic symptoms in breastfed infants. Non-IgE-mediated allergy, outside of food protein-induced allergic proctocolitis and eosinophilic oesophagitis, is not well understood, leading to variations in the diagnosis and management thereof. A primary objective of the European Academy for Allergy and Clinical Immunology is to support breastfeeding in all infants, including those with food allergies. A Task Force was established, to explore the clinical spectrum of non-IgE-mediated allergies, and part of its objectives was to establish diagnosis and management of non-IgE-mediated allergies in breastfed infants. Eight questions were formulated using the Patient, Intervention, Comparison, Outcome (PICO) system and Scottish Intercollegiate Guideline Network (SIGN) criteria for data inclusion, and consensus was achieved on practice points through the Delphi method. This publication aims to provide a comprehensive overview on this topic with practice points for healthcare professionals.

Severity scales of non-IgE-mediated gastrointestinal food allergies in neonates and infants

BACKGROUND

Non-IgE-mediated gastrointestinal food allergies (non-IgE-GI-FAs) are one type of food allergy found in neonates and infants. Few reports have defined the severity of non-IgE-GI-FAs in these populations.

METHODS

Grading scales of the severity of non-IgE-GI-FAs according to extra-GI symptoms, such as poor weight gain, as well as systemic symptoms, including fever and shock, were developed and retrospectively applied to patients with non-IgE-GI-FAs. The relationship between the severity of non-IgE-GI-FAs and both clinical and laboratory findings were examined.

RESULTS

Elevation of C-reactive protein levels and a decrease in total protein and albumin were observed in accordance with allergy severity. In an endoscopic examination, inflammatory findings were confirmed in large areas of the colonic mucosa in case of higher severity levels, and infiltration of inflammatory cells other than eosinophils was found in the severest grade. Extensively hydrolyzed milk or amino acid-based milk was required for all patients with the severest grade. In addition, the timing of acquiring tolerance tended to be late for this grade.

CONCLUSIONS

Classification and determination of the severity of non-IgE-GI-FAs in neonates and infants may not only contribute to elucidation of the pathogenesis but may also be useful in the clinical setting.

Deep analysis of immune response and metabolic signature in children with food protein induced enterocolitis to cow's milk

Background

Food Protein-Induced Enterocolitis Syndrome (FPIES) is considered to be a non-IgE mediated food allergy. However, its pathogenesis remains poorly understood and biomarkers are lacking. We aimed to perform in-depth characterization of humoral and cellular immune responses in children with cow’s milk (CM)-FPIES and investigated whether there is a FPIES metabolomic signature.

Methods

Children with CM-FPIES and control subjects with an IgE-mediated CM allergy (IgE-CMA), both avoiding CM, were recruited on the day of an oral food challenge. Blood samples were collected before the challenge. Total and specific levels of IgE, IgG1-4, IgA, IgM and IgD to various whey and casein allergens and to their gastroduodenal digestion products were measured in plasma, using plasma from CM-tolerant peanut allergic patients (IgE-PA, not avoiding CM) as additional controls. Cytokine secretion and cellular proliferation were analyzed after stimulation of PBMC with different CM allergens. Metabolomic profiles were obtained for plasma samples using liquid chromatography coupled to high-resolution mass spectrometry.

Results

Nine children with CM-FPIES and 12 control subjects (6 IgE-CMA and 6 IgE-PA) were included. In children with CM-FPIES, total Ig concentrations were lower than in control subjects, specific Ig against CM components were weak to undetectable, and no specific IgE against CM digestion products were detected. Moreover, in CM-FPIES patients, we did not find any Th cell proliferation or associated cytokine secretion after allergen reactivation, whereas such responses were clearly found in children with IgE-CMA. Plasma metabolic profiles were different between CM allergic patients, with significantly lower concentrations of various fatty acids and higher concentrations of primary metabolites such as amino acids in CM-FPIES compared to IgE-CMA patients.

Conclusions

In CM-FPIES, both humoral and cellular specific immune responses are weak or absent, and this is not related to CM avoidance. A metabolomic signature was identified in patients with CM-FPIES that may be useful for the diagnosis and management of this disease.

Electronic supplementary material

The online version of this article (10.1186/s13601-018-0224-9) contains supplementary material, which is available to authorized users.

Non-IgE-mediated food hypersensitivity

Non-immunoglobulin E (IgE)-mediated food hypersensitivity includes a spectrum of disorders that predominantly affect the gastrointestinal tract. This review will focus on the following more common non-IgE-mediated food hypersensitivity syndromes: food protein-induced enterocolitis syndrome (FPIES), allergic proctocolitis (AP), food protein-induced enteropathy (FPE) and celiac disease. FPIES, AP and FPE typically present in infancy and are most commonly triggered by cow’s milk protein or soy. The usual presenting features are profuse emesis and dehydration in FPIES; blood-streaked and mucousy stools in AP; and protracted diarrhea with malabsorption in FPE. Since there are no confirmatory noninvasive diagnostic tests for most of these disorders, the diagnosis is based on a convincing history and resolution of symptoms with food avoidance. The mainstay of management for FPIES, AP and FPE is avoidance of the suspected inciting food, with periodic oral food challenges to assess for resolution, which generally occurs in the first few years of life. Celiac disease is an immune-mediated injury caused by the ingestion of gluten that leads to villous atrophy in the small intestine in genetically susceptible individuals. Serologic tests and small intestinal biopsy are required to confirm the diagnosis of celiac disease, and management requires life-long adherence to a strict gluten-free diet.

The prevalence and characteristics of cow's milk protein allergy in infants and young children with iron deficiency anemia

BACKGROUND

The clinical presentation of cow's milk protein allergy (CMPA) in children varies. This retrospective study aimed to investigate the prevalence and clinical manifestations of CMPA in young children who visited for evaluation of iron deficiency anemia (IDA).

METHODS

Patients aged <4 years who were diagnosed as having IDA (serum ferritin <12 ng/mL) at the National Cheng Kung University Hospital, Taiwan in the period 2005-2015 were reviewed. Their clinical presentations, laboratory data, endoscopy findings, and prognosis were analyzed.

RESULTS

Seven of 51 IDA patients (13.7%) had CMPA. The pallor (100%), failure to thrive (43%), and general edema (43%) were the common features. Six (86%) had hypoalbuminemia and four (57%) had positive occult blood in the stool. Of the five patients who underwent skin prick test, four (80%) had positive results. Most of the colonoscopies revealed erosive and hemorrhagic colitis and lymphoid hyperplasia, but none of the biopsies demonstrated eosinophilia in the lamina propria. All of the patients recovered from their IDA within seven months of cow's milk protein elimination and iron supplementation.

CONCLUSION

CMPA should be considered in young children with undetermined IDA. Cow's milk protein elimination and iron supplementation help in the recovery.

Fecal microbiota transplantation induces remission of infantile allergic colitis through gut microbiota re-establishment

AIM

To investigate the impact of fecal microbiota transplantation (FMT) treatment on allergic colitis (AC) and gut microbiota (GM).

METHODS

We selected a total of 19 AC infants, who suffered from severe diarrhea/hematochezia, did not relieve completely after routine therapy or cannot adhere to the therapy, and were free from organ congenital malformations and other contraindications for FMT. Qualified donor-derived stools were collected and injected to the AC infants via a rectal tube. Clinical outcomes and follow-up observations were noted. Stools were collected from ten AC infants before and after FMT, and GM composition was assessed for infants and donors using 16S rDNA sequencing analysis.

RESULTS

After FMT treatment, AC symptoms in 17 infants were relieved within 2 d, and no relapse was observed in the next 15 mo. Clinical improvement was also detected in the other two AC infants who were lost to follow-up. During follow-up, one AC infant suffered from mild eczema and recovered shortly after hormone therapy. Based on the 16S rDNA analysis in ten AC infants, most of them (n = 6) had greater GM diversity after FMT. As a result, Proteobacteria decreased (n = 6) and Firmicutes increased (n = 10) in post-FMT AC infants. Moreover, Firmicutes accounted for the greatest proportion of GM in the patients. At the genus level, Bacteroides (n = 6), Escherichia (n = 8), and Lactobacillus (n = 4) were enriched in some AC infants after FMT treatment, but the relative abundances of Clostridium (n = 5), Veillonella (n = 7), Streptococcus (n = 6), and Klebsiella (n = 8) decreased dramatically.

CONCLUSION

FMT is a safe and effective method for treating pediatric patients with AC and restoring GM balance.

Epidemiology of Food Allergy

Understanding the epidemiology of food allergy is complicated by the difficulty of identifying it on a large scale. The prevalence of food allergy is higher in younger age groups and decreases with age. Allergy to peanut and egg seems to be more common in Northern Europe, the United States, Canada and Australia compared with Southern Europe, Eastern Europe and Asia, whereas shellfish and fish allergies may be more common in Asia. The rate of transient unrecognized food allergy may be high and variable recognition of food allergy may explain some of the differences seen in food allergy prevalence.

Optimizing an Aversion Feeding Therapy Protocol for a Child with Food Protein-Induced Enterocolitis Syndrome (FPIES)

This case study examines the difficulties of treating food aversion in a 9-month old child with a diagnosis of Food Protein-Induced Enterocolitis Syndrome (FPIES). Given the need to first identify a set of "safe foods" with which to work, the twin goals of doing food challenges and minimizing aversion are initially not complimentary, and require an approach outside the standard of care. The chosen plan encouraged flexibility and a positive relationship with feeding-related items, while only introducing one food item at a time. Mom and child accomplished goals surrounding food play easily. She has successfully introduced a wide variety of new foods in small quantities and is currently working on reducing dependence on breast milk. Therapists must be prepared to modify currently accepted interventions to accommodate and support the required medical intervention.