IgE-mediated food allergy

[IgE- and non-IgE-mediated food allergies - an overview]

Food allergies are divided into 2 main categories: IgE-mediated and non-IgE-mediated food allergies. Both forms can have significant health effects but differ in mechanism, symptoms, and management. The manifestation of the 2 forms differs between children and adults. These differences can be observed in the prevalence and the type of most common allergens and clinical presentation. The prevalence of food allergies has increased worldwide in recent decades. IgE-mediated allergies are the best researched and documented. They are particularly common in children, while non-IgE-mediated allergies are less well understood and diagnosed, leading to uncertainty about their prevalence. They often manifest as gastrointestinal symptoms that can occur hours to days after ingestion and are often difficult to distinguish from other food intolerances. The occurrence of food allergies varies significantly geographically. Differences in dietary habits, food composition, and environmental factors can partly explain these differences. There are also indications that genetics may play a role. IgE-mediated and non-IgE-mediated food allergies represent a significant and growing challenge for the global healthcare system. This article provides an in-depth review of both types of food allergy, discussing their potential causes, diagnostic possibilities, and available therapeutic strategies. Some diseases represent a mixed form of IgE and non-IgE-mediated immunological adverse reactions. Eosinophilic oesophagitis is the most common eosinophilic disease, and the diagnosis and treatment options are explained in more detail below.

The impact of high-IgE levels on metabolome and microbiome in experimental allergic enteritis

BACKGROUND

The pathological mechanism of the gastrointestinal forms of food allergies is less understood in comparison to other clinical phenotypes, such as asthma and anaphylaxis Importantly, high-IgE levels are a poor prognostic factor in gastrointestinal allergies.

METHODS

This study investigated how high-IgE levels influence the development of intestinal inflammation and the metabolome in allergic enteritis (AE), using IgE knock-in (IgEki) mice expressing high levels of IgE. In addition, correlation of the altered metabolome with gut microbiome was analysed.

RESULTS

Ovalbumin-sensitized and egg-white diet-fed (OVA/EW) BALB/c WT mice developed moderate AE, whereas OVA/EW IgEki mice induced more aggravated intestinal inflammation with enhanced eosinophil accumulation. Untargeted metabolomics detected the increased levels of N-tau-methylhistamine and 2,3-butanediol, and reduced levels of butyric acid in faeces and/or sera of OVA/EW IgEki mice, which was accompanied with reduced Clostridium and increased Lactobacillus at the genus level. Non-sensitized and egg-white diet-fed (NC/EW) WT mice did not exhibit any signs of AE, whereas NC/EW IgEki mice developed marginal degrees of AE. Compared to NC/EW WT mice, enhanced levels of lysophospholipids, sphinganine and sphingosine were detected in serum and faecal samples of NC/EW IgEki mice. In addition, several associations of altered metabolome with gut microbiome-for example Akkermansia with lysophosphatidylserine-were detected.

CONCLUSIONS

Our results suggest that high-IgE levels alter intestinal and systemic levels of endogenous and microbiota-associated metabolites in experimental AE. This study contributes to deepening the knowledge of molecular mechanisms for the development of AE and provides clues to advance diagnostic and therapeutic strategies of allergic diseases.

Food allergy spectrum in the tropic: clinical and epidemiological profiles in a colombian hospital. A cross-sectional study

Introduction

Food allergy affects 2-10% of the general population; it is more frequent among children than among adults, and it is one of the leading causes of anaphylaxis. Diagnosis of food allergy requires a detailed medical history, skin tests, specific immunoglobulin E (IgE) tests for the food involved, and an oral challenge as final confirmation.

Objectives

This study aimed to describe the clinical and epidemiological characteristics of patients who underwent oral food challenges for suspected food allergies in a reference center in Colombia.

Methodology

An observational, descriptive, cross-sectional and retrospective study was conducted. Data were retrospectively collected from patients who were evaluated in the allergology service and suspected of food allergy from 2011 to 2018. Quantitative variables are presented as means or medians depending on the normality of the distribution (assessed by the Shapiro-Wilk test), and categorical variables are presented as frequencies and percentages.

Results

A total of 215 controlled open challenges were performed on 176 patients, most of whom were children (69%). Thirty-one patients (17%) required another oral challenge with a second food, and 11 (6.25%) required another oral challenge with three foods. Twelve oral challenges (5.58%) were positive. Of these, five challenges were positive for cow's milk, 5 were positive for shrimp, and 2 were positive for legumes (peanuts and lentils).

Conclusion

The frequency of confirmed food allergies and the profile of food allergies in our population differs from that reported in other parts of the world.

The origins and longevity of IgE responses as indicated by serological and cellular studies in mice and humans

The existence of long-lived IgE antibody-secreting cells (ASC) is contentious, with the maintenance of sensitization by the continuous differentiation of short-lived IgE+ ASC a possibility. Here, we review the epidemiological profile of IgE production, and give an overview of recent discoveries made on the mechanisms regulating IgE production from mouse models. Together, these data suggest that for most individuals, in most IgE-associated diseases, IgE+ ASC are largely short-lived cells. A subpopulation of IgE+ ASC in humans is likely to survive for tens of months, although due to autonomous IgE B cell receptor (BCR) signaling and antigen-driven IgE+ ASC apoptosis, in general IgE+ ASC probably do not persist for the decades that other ASC are inferred to do. We also report on recently identified memory B cell transcriptional subtypes that are the likely source of IgE in ongoing responses, highlighting the probable importance of IL-4Rα in their regulation. We suggest the field should look at dupilumab and other drugs that prohibit IgE+ ASC production as being effective treatments for IgE-mediated aspects of disease in most individuals.

Carrot-Induced Systemic Reaction: A Unique Presentation of Pollen-Food Allergy Syndrome in a Young Boy

Pollen-food allergy syndrome (PFAS) is a common IgE-mediated allergic condition resulting from cross-reactions between pollen and plant food allergens, primarily those in the PR-10 subfamily. Mostly symptoms are limited to the mouth and throat causing oral allergy syndrome (OAS). Systemic reactions are extremely rare. We report an 11-year-old boy who experienced a unique anaphylactic reaction after consuming raw carrot juice. The patient exhibited symptoms within one minute, including abdominal pain, facial and eyelid swelling, dyspnea, a macular rash, choking sensation and drowsiness. Desloratadine alleviated these symptoms, and as his overall condition improved rapidly, there was no need for adrenaline administration. Carrot-specific IgE levels in the patient's serum were as follows: Dau c: 40.63 kUA/L and Dau c1: 31.5 kUA/L. He had previously been diagnosed with seasonal allergic rhinoconjunctivitis. The high degree of similarity among allergen components within the PR-10 subfamily contributed to cross-reactivity between birch pollen and carrots. It is important to remember that PFAS can manifest systemically, with symptoms ranging from mild skin itching to potentially fatal consequences. This highlights the need for healthcare professionals to be extra cautious and aware of this possibility, especially since carrots are commonly found in a wide range of dishes and snacks.

Efficacy and safety of oral immunotherapy for peanut, cow's milk, and hen's egg allergy: A systematic review of randomized controlled trials

BACKGROUND

Oral immunotherapy (OIT) is a promising treatment for food allergies; however, safety is a concern. We synthesized evidence from the best randomized controlled trials (RCTs) on efficacy/safety of OIT for desensitization (DS) and remission (sustained unresponsiveness (SU)) in IgE mediated allergy to peanut, hen's eggs, and cow's milk. BODY: We searched Pubmed, EMBASE, and Cochrane databases (Until Oct 22) identifying 16 eligible RCTs published in English measuring food allergy by food challenge at the beginning and at the end of the study. The Cochrane Risk of Bias tool was used to assess study quality. We found 18 eligible studies. There was evidence of efficacy for DS for all allergens: peanut (RR 11.32; 95% CI 5.93, 21.60, I2 49%, 8 studies); hen's egg (RR 4.67; 2.66, 8.21, I2 0%, 5 studies); cow's milk (RR 13.98; 3.51, 55.65, I2 0%, 4 studies) and evidence for SU for peanut (RR 7.74; 2.90, 20.69, I2 0%, 3 studies) and hen's egg (RR 6.91; 1.67, 28.57, I2 0%, 2 studies). Allergic events were increased with intervention, and risk of adrenaline use increased for peanut RR 2.96; 1.63, 5.35, I2 0%, 8 studies; egg RR 1.71; 0.42, 6.92, I2 0%, 6 studies; and milk RR 8.45; 2.02, 35.27, I2 0%, 4 studies.

CONCLUSION

We found strong evidence that peanut, hen's egg, and cow's milk OIT can induce DS and some evidence for remission. There was a high risk of allergic reactions. Generalizability to the entire food allergic population is not known.

Birth order, sibship size, and risk of atopic dermatitis, food allergy, and atopy: A systematic review and meta-analysis

BACKGROUND

Atopic dermatitis and food allergy are two frequently concomitant manifestations of the presence of atopy. A substantial number of studies have been published on the association of birth order and sibship size (number of siblings) with atopic dermatitis, food allergy, and atopy. The present work is the first systematic synthesis of the existing literature on this topic.

METHODS

Fifteen databases were searched. Screening, data extraction, and quality assessment were performed by independent pairs. Comparable numerical data were statistically synthesized using random-effects robust variance estimation.

RESULTS

In total, 114 studies were included out of 8819 papers obtained from database searches. Birth order ≥2 versus 1 was associated with lower risk of ever atopic dermatitis (pooled risk ratio [RR] 0.91, 95% CI 0.84-0.98), current food allergy (RR 0.77, 95% CI 0.66-0.90), and positive skin prick test (SPT) to common aeroallergens (RR 0.86, 95% CI 0.77-0.97). Sibship size ≥2 versus 1 was associated with decreased risk of current atopic dermatitis (RR 0.90, 95% CI 0.83-0.98), ever atopic dermatitis (RR 0.92, 95% CI 0.86-0.97), and positive SPT to common aeroallergens (RR 0.88, 95% CI 0.83-0.92). No putative associations were seen regarding atopy assessed through allergen-specific immunoglobulin E with common allergens.

CONCLUSION

The presence of siblings and being second-born or later may decrease the lifetime risk of atopic dermatitis and food allergy, albeit marginally. Similar association was seen with SPT sensitization. However, significant protection was not found for IgE sensitization.

Relationship Between Atopic Dermatitis and Food Allergy in Children

Atopic dermatitis (AD) is a chronic inflammatory skin condition characterized by a compromised skin barrier due to a variety of reasons, such as hereditary predisposition, immunological overactivity, and skin microbiome disruption. There is strong evidence linking food allergies (FA) with AD in some children, and many children with AD develop asymptomatic food sensitivity. FA and AD are two frequent childhood illnesses that are closely related. Food allergies affect 30% of kids suffering from moderate and severe eczema and can cause a variety of symptoms, including dry, cracked skin, rash, itchiness, oozing, and crusted skin. While preteens and teens with AD are commonly sensitive to environmental allergens including house dust mites, mold, pollen, or dander of animals, younger kids with AD typically exhibit sensitivity to food items like peanuts, milk, or eggs. A food challenge test (FC) should be used to confirm allergies before recommending a stringent diet that could be hazardous to the patient. While elimination diets continue to be the cornerstone of the management of FA, they should only be carried out under the guidance of a specialist. Topical treatments are crucial for all individuals with AD. Early skin care with emollients, topical steroid treatment, and early introduction of highly allergenic foods are promising methods of alleviating symptoms of AD.

Alteration of the allergenicity of cow's milk proteins using different food processing modifications

Milk is an essential source of protein for infants and young children. At the same time, cow's milk is also one of the most common allergenic foods causing food allergies in children. Recently, cow's milk allergy (CMA) has become a common public health issue worldwide. Modern food processing technologies have been developed to reduce the allergenicity of milk proteins and improve the quality of life of patients with CMA. In this review, we summarize the main allergens in cow's milk, and introduce the recent findings on CMA responses. Moreover, the reduced effects and underlying mechanisms of different food processing techniques (such as heating, high pressure, γ-ray irradiation, ultrasound irradiation, hydrolysis, glycosylation, etc.) on the allergenicity of cow's milk proteins, and the application of processed cow's milk in clinical studies, are discussed. In addition, we describe the changes of nutritional value in cow's milk treated by different food processing technologies. This review provides an in-depth understanding of the allergenicity reduction of cow's milk proteins by various food processing techniques.

Oral Metronidazole Desensitization for Immunoglobulin E (IgE)-Mediated Hypersensitivity

Low efficacy has been reported for the treatment of Trichomonas vaginalis with antimicrobial agents other than the 5-nitroimidazole class. Patients with immunoglobulin E (IgE)-mediated hypersensitivity reactions to drugs in this class, including metronidazole and tinidazole, may benefit from a desensitization treatment. We present two patients with past medical histories of IgE-mediated hypersensitivity reactions to metronidazole who were successfully treated with metronidazole using a modified protocol. The first patient was a 39-year-old female diagnosed with trichomoniasis who had a previous reaction to metronidazole characterized by urticaria and pruritus. The second patient was a 53-year-old female who had a history of untreated trichomoniasis due to a previous anaphylactic reaction to metronidazole. Both patients were successfully treated in the intensive care unit (ICU) without signs and symptoms of the reaction. Physicians may use a desensitization protocol for patients with a presumed IgE-mediated hypersensitivity when only the 5-nitroimidazole class is efficacious for the treatment of trichomoniasis.

It takes a village: perceptions of Winnipeg parents, students, teachers and school staff regarding the impact of food allergy on school-age students and their families

Background

The entire school community contributes to the safety of students with food allergy. We sought to determine the food allergy perceptions and education needs of parents, students and school staff, with the goal of enhancing food allergy education in schools.

Methods

With ethics approval from the University of Manitoba and participating school divisions, elementary school principals emailed SurveyMonkey^® Questionnaire Links to their parent/caregiver contact list and school staff. We compared anonymous responses of parents of children with and without food allergy, students with and without food allergy, and parents and school staff using chi-squared tests.

Results

Participants included 561 parents of school-age children (ages 7–12 years, 19% with food allergy), 61 students (23% with food allergy), and 203 school staff (62% teachers, 88% with experience managing food allergies in the classroom). Parents of children with and without food allergy considered food allergy when sending food to school (98% vs. 96%, p = 0.39). More parents of children with food allergy thought that greater information and awareness about food allergy was needed (74% vs. 44%, p < 0.0001). Students with food allergy were most interested (100%) in having other students learn not to bully and how to help during a reaction. Students without food allergy were most interested in learning how to prevent a reaction (70%). Fewer parents than school staff thought that food allergies in the classroom impacted teachers’ time (2.1% vs. 21%, p < 0.0001) and that teachers knew how to treat allergic reactions to foods (34% vs. 94%, p < 0.0001). More parents than school staff thought that banning foods from classrooms kept allergic students safe (65% vs. 34%, p = 0.006) and that having a Food Allergy Educator speak at school would be helpful (99% vs. 67%, p < 0.0001).

Conclusions

Food allergy education is necessary for the entire school community and should include parents of school-aged children with and without food allergy, students with and without food allergy, and teachers and school staff. These members of the school community recognized their own and others’ needs for increased food allergy education and awareness in the school setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00682-2.

The Role of Lipids in Allergic Sensitization: A Systematic Review

Background: Immunoglobulin E (IgE)-mediated allergies are increasing in prevalence, with IgE-mediated food allergies currently affecting up to 10% of children and 6% of adults worldwide. The mechanisms underpinning the first phase of IgE-mediated allergy, allergic sensitization, are still not clear. Recently, the potential involvement of lipids in allergic sensitization has been proposed, with reports that they can bind allergenic proteins and act on immune cells to skew to a T helper type 2 (Th2) response. Objectives: The objective of this systematic review is to determine if there is strong evidence for the role of lipids in allergic sensitization. Methods: Nineteen studies were reviewed, ten of which were relevant to lipids in allergic sensitization to food allergens, nine relevant to lipids in aeroallergen sensitization. Results: The results provide strong evidence for the role of lipids in allergies. Intrinsic lipids from allergen sources can interact with allergenic proteins to predominantly enhance but also inhibit allergic sensitization through various mechanisms. Proposed mechanisms included reducing the gastrointestinal degradation of allergenic proteins by altering protein structure, reducing dendritic cell (DC) uptake of allergenic proteins to reduce immune tolerance, regulating Th2 cytokines, activating invariant natural killer T (iNKT) cells through CD1d presentation, and directly acting upon toll-like receptors (TLRs), epithelial cells, keratinocytes, and DCs. Conclusion: The current literature suggests intrinsic lipids are key influencers of allergic sensitization. Further research utilising human relevant in vitro models and clinical studies are needed to give a reliable account of the role of lipids in allergic sensitization.

Tree Nuts and Peanuts as a Source of Beneficial Compounds and a Threat for Allergic Consumers: Overview on Methods for Their Detection in Complex Food Products

Consumption of tree nuts and peanuts has considerably increased over the last decades due to their nutritional composition and the content of beneficial compounds. On the other hand, such widespread consumption worldwide has also generated a growing incidence of allergy in the sensitive population. Allergy to nuts and peanuts represents a global relevant problem, especially due to the risk of the ingestion of hidden allergens as a result of cross-contamination between production lines at industrial level occurring during food manufacturing. The present review provides insights on peanuts, almonds, and four nut allergens—namely hazelnuts, walnuts, cashew, and pistachios—that are likely to cross-contaminate different food commodities. The paper aims at covering both the biochemical aspect linked to the identified allergenic proteins for each allergen category and the different methodological approaches developed for allergens detection and identification. Attention has been also paid to mass spectrometry methods and to current efforts of the scientific community to identify a harmonized approach for allergens quantification through the detection of allergen markers.

Protocol for a systematic review of the diagnostic test accuracy of tests for IgE-mediated food allergy

BACKGROUND

The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of updating the guidelines on the diagnosis and management of food allergy. The existing guidelines are based on a systematic review of the literature until 30 September 2012. Therefore, a new systematic review must be undertaken to inform the new guidelines. This systematic review aims to assess the accuracy of index tests to support the diagnosis of IgE-mediated food allergy.

METHODS

The databases Cochrane CENTRAL (Trials), MEDLINE (OVID) and Embase (OVID) will be searched for diagnostic test accuracy studies from 1 October 2012 to 30 June 2021. Inclusion and exclusion criteria will be used to select appropriate studies. Data from these studies will be extracted and tabulated, and then reviewed for risk of bias and applicability using the QUADAS-2 tool. All evaluations will be done in duplicate. Studies with a high risk of bias and low applicability will be excluded. Meta-analysis will be performed if there are three or more studies of the same index test and food.

RESULTS

A protocol for the systematic review and meta-analyses is presented and was registered using Prospero prior to commencing the literature search.

DISCUSSION

Oral food challenges are the reference standard for diagnosis but involve considerable risks and resources. This protocol for systematic review aims to assess the accuracy of various tests to diagnose food allergy, which can be useful in both clinical and research settings.

Breeding Canola (Brassica napus L.) for Protein in Feed and Food

Interest in canola (Brassica napus L.). In response to this interest, scientists have been tasked with altering and optimizing the protein production chain to ensure canola proteins are safe for consumption and economical to produce. Specifically, the role of plant breeders in developing suitable varieties with the necessary protein profiles is crucial to this interdisciplinary endeavour. In this article, we aim to provide an overarching review of the canola protein chain from the perspective of a plant breeder, spanning from the genetic regulation of seed storage proteins in the crop to advancements of novel breeding technologies and their application in improving protein quality in canola. A review on the current uses of canola meal in animal husbandry is presented to underscore potential limitations for the consumption of canola meal in mammals. General discussions on the allergenic potential of canola proteins and the regulation of novel food products are provided to highlight some of the challenges that will be encountered on the road to commercialization and general acceptance of canola protein as a dietary protein source.

Potential Biomarkers, Risk Factors and their Associations with IgE-mediated Food Allergy in Early Life: A Narrative Review

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. In the past few decades, the prevalence of allergic disease has been on the rise worldwide. Identified risk factors for food allergy include family history, mode of delivery, variations in infant feeding practices, prior diagnosis of other atopic diseases such as eczema, and social economic status. Identifying reliable biomarkers which predict the risk of developing food allergy in early life would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. There is also the potential to identify new therapeutic targets. This narrative review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy and synthesizes the currently available data indicating potential biomarkers. While there is a large body of research evidence available within each field of potential risk factors, there are very limited number of studies which span multiple methodological fields, for example including immunology, microbiome, genetic/epigenetic factors and dietary assessment. We recommend that further collaborative research with detailed cohort phenotyping is required to identify biomarkers, and whether these vary between at-risk populations and the wider population. The low incidence of oral food challenge confirmed food allergy in the general population, and the complexities of designing nutritional intervention studies will provide challenges for researchers to address in generating high quality, reliable and reproducible research findings.

STATEMENT OF SIGNIFICANCE

Food allergy affects the quality of life of millions of people worldwide and presents a significant psychological and financial burden for both national and international public health. Identifying reliable biomarkers which predict the risk of developing food allergy would be valuable in both preventing morbidity and mortality and by making current interventions available at the earliest opportunity. This review provides details on the genetic, epigenetic, dietary and microbiome influences upon the development of food allergy. This helps in identifying reliable biomarkers to predict the risk of developing food allergy, which could be valuable in both preventing morbidity and mortality and by making interventions available at the earliest opportunity.

NIgPred: Class-Specific Antibody Prediction for Linear B-Cell Epitopes Based on Heterogeneous Features and Machine-Learning Approaches

Upon invasion by foreign pathogens, specific antibodies can identify specific foreign antigens and disable them. As a result of this ability, antibodies can help with vaccine production and food allergen detection in patients. Many studies have focused on predicting linear B-cell epitopes, but only two prediction tools are currently available to predict the sub-type of an epitope. NIgPred was developed as a prediction tool for IgA, IgE, and IgG. NIgPred integrates various heterologous features with machine-learning approaches. Differently from previous studies, our study considered peptide-characteristic correlation and autocorrelation features. Sixty kinds of classifier were applied to construct the best prediction model. Furthermore, the genetic algorithm and hill-climbing algorithm were used to select the most suitable features for improving the accuracy and reducing the time complexity of the training model. NIgPred was found to be superior to the currently available tools for predicting IgE epitopes and IgG epitopes on independent test sets. Moreover, NIgPred achieved a prediction accuracy of 100% for the IgG epitopes of a coronavirus data set. NIgPred is publicly available at our website.

Tick Saliva and the Alpha-Gal Syndrome: Finding a Needle in a Haystack

Ticks and tick-borne diseases are significant public health concerns. Bioactive molecules in tick saliva facilitate prolonged blood-feeding and transmission of tick-borne pathogens to the vertebrate host. Alpha-gal syndrome (AGS), a newly reported food allergy, is believed to be induced by saliva proteins decorated with a sugar molecule, the oligosaccharide galactose-⍺-1,3-galactose (α-gal). This syndrome is characterized by an IgE antibody-directed hypersensitivity against α-gal. The α-gal antigen was discovered in the salivary glands and saliva of various tick species including, the Lone Star tick (Amblyomma americanum). The underlying immune mechanisms linking tick bites with α-gal-specific IgE production are poorly understood and are crucial to identify and establish novel treatments for this disease. This article reviews the current understanding of AGS and its involvement with tick species.

Electrochemical and optical biosensing platforms for the immunorecognition of hazelnut Cor a 14 allergen

Two immunosensors were advanced to target hazelnut Cor a 14 based on electrochemical and optical transduction. Both approaches were developed with two types of custom-made antibodies, namely anti-Cor a 14 IgG (rabbit) and anti-Cor a 14 IgY (hen's egg) targeting the Cor a 14 allergen. Antibody immobilisation was performed via EDC/NHS onto disposable screen-printed electrodes. The detection limit (LOD) of the electrochemical immunoassay for Cor a 14 was 5-times lower than the optical, being down to 0.05 fg mL^-1 with a dynamic range of 0.1 fg mL^-1 to 0.01 ng mL^-1. Antibody selectivity was verified against non-target 2S albumins (potential cross-reactive plant species). Anti-Cor a 14 IgY exhibited the best specificity, presenting minor cross-reactivity with peanut/walnut. Preliminary results of the application of anti-Cor a 14 IgY electrochemical immunosensor to incurred foods established a LOD of 1 mg kg^-1 of hazelnut in wheat (0.16 mg kg^-1 hazelnut protein).

Colonic mucosal eosinophilia in children without inflammatory bowel disease

Children undergoing colonoscopy and mucosal biopsies may show increased colonic mucosal eosinophils, which may or may not be associated with inflammatory bowel disease. There is not much clinical data on American children who have isolated increased colonic mucosal eosinophils. We sought to study the clinical correlates of children without inflammatory bowel disease who show increased mucosal eosinophils to understand their clinical presentation, etiological associations, and outcome. A retrospective analysis of children seen at a tertiary-level Children's hospital was performed by reviewing their medical charts and extracting pertinent data. There were 110 children in the study who had increased colonic mucosal eosinophils. Most children presented with abdominal pain, but several of them also had constipation, blood in stools, and diarrhea. Food allergies, irritable bowel syndrome, asthma, and lactase deficiency were the top four conditions present in these patients. Pathology of the colonic distribution revealed involvement of more than two colonic regions in 86% of the subjects, and only two subjects showing epithelial or crypt involvement by eosinophils. All subjects had a good outcome. Children with colonic mucosal eosinophilia (CME) who do not have an inflammatory bowel disease most frequently present with abdominal pain and primarily an increase of lamina propria eosinophils in two or more colonic regions. Based on the etiological associations we noted in the study, a work-up of children with CME may encompass detailed history for functional gastrointestinal disorders and lactose intolerance, testing for food and environmental allergies, stool examination for parasites, and peripheral blood counts. Almost all children had resolution of symptoms in the studied period suggesting that CME in children has a good clinical outcome.

A case of hand urticaria, lip angioedema, and oropharyngeal pruritus induced by Japanese radish through IgE-mediated immediate allergic reaction

Background

Although Japanese radish (Raphanus sativus L.) is a common Japanese ingredient, there are few reports of IgE-mediated immediate food allergy caused by Japanese radish.

Case presentation

A 48-year-old woman developed urticarial lesions on her hands after grating Japanese radish and also developed lip edema and oral itching when she ate a salad composed of raw Japanese radishes. Skin prick testing was positive to extract of grated Japanese radish. Moreover, immunoblotting analysis showed IgE reactivity in the patient’s serum to a single band at the 18 kDa in grated Japanese radish, suggesting that the heat-labile 18 kDa protein of raw Japanese radish may be a radish-specific antigen.

Conclusions

To the best of our knowledge, this is the first case report of a patient with hand urticaria, lip angioedema, and oropharyngeal pruritus to raw Japanese radish through IgE-mediated immediate allergic reaction.

A Snapshot on Food Allergies: A Case Study on Edible Flowers

This perspective study addresses the main causes of adverse reactions to foods in humans, by taking into account the main allergic reactions that may occur as a result of food ingestion, as well the main allergens present in food and how their allergenicity change as a result of food preparation. In addition, European legislation on food labeling and novel foods was taken into account. The case study of this perspective is on the potential allergenicity of edible flowers as well as evidence of phytochemistry and toxic compounds and the risk associated with their ingestion. Regarding edible flowers, a key issue to address is if they are safe to consume or not. In the framework of the project “Innovative activities for the development of the cross-border supply chain of the edible flower” (ANTEA), we considered 62 different species and varieties of edible flowers. The results obtained by consulting two databases on allergens, COMPRISE and Allergen Nomenclature, marked two alerts for two species of edible flowers selected in the project. Moreover, based on edible flower consumption, about ten grams per serving, and on their protein content, we can also state that the risk of allergic reactions due to edible flower ingestion is very low.

Adult-onset IgE-mediated food allergy at a Winnipeg allergy clinic: a case series

BACKGROUND

It is a putatively understood phenomenon that the overall prevalence of allergic disease has been increasing in recent decades-particularly in industrialized nations. Despite this, there is a relative scarcity of data concerning the development of food-related allergic disease in the adult population. In addition, the paucity of data as it pertains to the Canadian population is particularly marked when compared to other nations. We sought to determine common culprit foods and the reactions they elicited in a series of 14 patients seen in the Winnipeg allergy and immunology clinic.

METHODS

We conducted a retrospective review of patients identified by academic allergists in Winnipeg, Manitoba as fitting criteria for adult-onset IgE-mediated food allergy from May 2018-July 2020. We included patients with IgE-mediated symptoms, including the pollen-food syndrome which developed at the age of 16 or later. We collected data regarding the food which induced the reaction, what the reaction was, and any concomitant atopic disease.

RESULTS

The most common culprit food identified was shellfish, followed by finfish, pollen-food syndrome, and wheat/flour. The most common reaction experienced was anaphylaxis, followed by food-dependent exercise-induced anaphylaxis and isolated (muco)cutaneous symptoms. With regard to concomitant atopic disease, allergic rhinitis/rhinoconjunctivitis stood out as the most prevalent.

CONCLUSIONS

Adult-onset food allergy-particularly with resultant anaphylaxis-is an important phenomenon to recognize, even when patients have previously tolerated the food in question.

Food protein-induced allergic proctocolitis may have distinct phenotypes

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is a non-immunoglobulin E (IgE)-mediated food allergy, which presents with bloody mucoid stool in infants. Although IgE-mediated allergy and sensitizations to offending foods have been described in other non-IgE-mediated food allergies, it has not been investigated in FPIAP.

OBJECTIVE

To investigate IgE-mediated allergy and sensitization to offending foods in FPIAP.

METHODS

Patients (n = 204) were retrospectively recruited and grouped as FPIAP (n = 180; FPIAP with or without the symptoms of IgE-mediated food hypersensitivity to offending and nonoffending foods at initial consultation), FPIAP-IgE sensitization to offending foods (n = 17), and FPIAP-transition to IgE-mediated allergy to offending foods (n = 7). The study was performed in accordance with the protocol approved by the local ethical committee of the Hacettepe University.

RESULTS

The median age of onset of symptoms and the development of tolerance was 2 months (interquartile range [IQR], 1.0-3.0) and 12 months (IQR, 10.0-14.0), respectively, and of the patients with skin prick test or serum specific IgE tests (n = 196), 38 (19.4%) had evidence of IgE sensitization to offending foods at the initial consultation or during follow-up; 17 (8.6%) had IgE sensitization, 7 (3.6%) indicated a transition to IgE-mediated allergy to FPIAP-induced foods. The median age of tolerance development of the FPIAP-transition group (19 months, IQR, 18.0-29.0) was significantly later than that of the FPIAP group (11 months, IQR, 10.0-14.0; P < .001) and the FPIAP-IgE sensitization group (11.0 months, IQR, 9.5-12.0; P < .001). Tolerance was observed within the study period in almost all the patients.

CONCLUSION

Children with FPIAP may have sensitization or develop IgE-mediated allergy over time to offending foods. In addition, IgE sensitization in FPIAP does not have an unfavorable effect on tolerance development; however, the transition to an IgE-mediated phenotype may delay tolerance for a brief time.

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.

Evidence-based and mechanistic insights into exclusion diets for IBS

Exclusion diets are becoming increasingly popular in the management of irritable bowel syndrome (IBS). Several mechanisms exist by which food items might cause gastrointestinal symptoms, such as direct osmotic effects of food in the gut lumen, changes to the gut microbiota and immune activation. These effects have been demonstrated in animal models and in human studies, particularly in the case of gluten-free diets and diets low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs). Indeed, randomized controlled trials (RCTs) suggest that gluten-free diets and low-FODMAP diets improve IBS symptoms, and guidelines recommend the latter approach for treating symptoms in some patients with IBS. Designing such RCTs is challenging as participants need to eat so an 'inert' placebo is not an option. Blinding is also an issue with these studies; in the future, new exclusion diets should not advertise what the diet consists of until it is proved to reduce symptoms. In this Review, we outline the advantages and disadvantages of each choice of control group and emphasize the importance of collecting mechanistic data (regarding direct effects of food on the gut lumen, changes in gut microbiota and intestinal inflammation) as well as symptom data in RCTs of exclusion diets in IBS.

Food Elimination in the Management of Refractory Chronic Rhinosinusitis: A Pilot Study

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most commonly reported chronic diseases. Refractory CRS represents a subgroup of patients who continue to be symptomatic even after adequate medical and surgical therapy. These patients started to form a significant portion of patients with CRS. Food elimination as a therapeutic method to control symptoms of different chronic diseases, such as eosinophilic esophagitis, asthma, and atopic dermatitis, has been described in the literature with variable success rates.

OBJECTIVES

To evaluate the effectiveness of food elimination therapy as adjuvant treatment in refractory patients having CRS with positive food sensitization.

DESIGN

Prospective open-label study.

SETTING

Tertiary academic center.

METHODS

Consecutive adult patients with refractory nonobstructive CRS (patients who had persistent sinonasal symptoms despite endoscopic sinus surgery and patent sinuses ostia with adequate medical treatment) with positive food sensitization were included. Subjects were asked to eliminate the sensitized food from their diet. Clinical outcome was assessed using the Lund-Kennedy symptom and Lund-Kennedy endoscopic appearance scores.

RESULTS

Twenty-two patients were initially enrolled in the study. Six patients were excluded; 4 were lost to follow-up, and 2 did not eliminate the causal food for the required period. The average age of the patients was 36 years old. There were 10 female and 6 male patients. Nasal discharge and facial pressure were the most common presenting symptoms. Shellfish, egg, and meat mix were the most common eliminated foods. There was a significant difference in the patients' Lund-Kennedy symptom and Lund-Kennedy endoscopic appearance scores at 6 and 12 weeks after food elimination therapy.

CONCLUSIONS

Food elimination in refractory CRS is an effective adjuvant treatment and should be considered in the treatment algorithm of patients with persistent symptoms after successfully performed sinus surgery.

Food Allergy Insights: A Changing Landscape

The panorama of food allergies (FA) has changed profoundly in recent years. In light of recent advances in knowledge of pathogenetic mechanisms and a greater attention to the multifaceted range of possible clinical manifestations, there is a need for a critical review of past classifications. Changes in nutrition, environment and lifestyles around the world are modifying the global FA epidemiology and new FA phenotypes are also emerging. Furthermore, both biotechnological advances in this field and recent personalized therapies have improved the diagnostic and therapeutic approach to FA. Consequently, both the prevention and clinical management of FA are rapidly changing and new therapeutic strategies are emerging, even revolutionizing the current medical practice. Given the significant increase in the prevalence of FA in recent years, the objective of this review is to provide an updated and complete overview of current knowledge in its etiopathogenesis, diagnostics and therapy, useful not only for a better understanding of this frequent and complex pathology but also for practical guidance in its clinical management.

Effect of Biospray Dressings on Eosinophil Infiltration in the Nasal Mucosa and Serum IgE Levels After Nasal Provocation in Experimental Allergic Rhinitis

Purpose

To investigate the effect of biospray dressing on the extent of eosinophil infiltration in the nasal mucosa and the level of serum IgE in experimental allergic rhinitis with nasal provocation.

Method

Twenty-four BALB/c mice were randomly divided into the normal control group, allergic rhinitis (AR) group, dexamethasone (DEX) treatment group, and biospray dressing (BD) group. The mice in the latter 3 groups were prepared for animal models of AR according to standard protocols. Mice in the BD group were administered a nasal spray before the nasal provocation, and those in the DEX group were administered an intraperitoneal injection of DEX. The nasal mucosa and serum were collected from each group. Nasal mucosa eosinophil infiltration was evaluated using hematoxylin and eosin staining, and enzyme-linked immunosorbent assay (ELISA) was performed to analyze the serum IgE expression.

Results

Eosinophil infiltration (AR vs BD P = .009) in the nasal mucosa and serum IgE expression (AR vs BD P = .001) were significantly lower in the BD group than in the AR group. There were no significant differences in the extent of eosinophil infiltration in the nasal mucosa or serum IgE expression between the BD and DEX groups.

Conclusion

Biospray dressings can significantly reduce allergen provocation in the nasal cavity and have a protective effect on the nasal mucosa. They can be used for the prevention and treatment of AR.

New Perspectives in Food Allergy

The improvement of the knowledge of the pathophysiological mechanisms underlying the tolerance and sensitization to food antigens has recently led to a radical change in the clinical approach to food allergies. Epidemiological studies show a global increase in the prevalence of food allergy all over the world and manifestations of food allergy appear increasingly frequent also in elderly subjects. Environmental and nutritional changes have partly changed the epidemiology of allergic reactions to foods and new food allergic syndromes have emerged in recent years. The deepening of the study of the intestinal microbiota has highlighted important mechanisms of immunological adaptation of the mucosal immune system to food antigens, leading to a revolution in the concept of immunological tolerance. As a consequence, new prevention models and innovative therapeutic strategies aimed at a personalized approach to the patient affected by food allergy are emerging. This review focuses on these new perspectives and their practical implications in the management of food allergy, providing an updated view of this complex pathology.

Allergen components in diagnosing childhood hazelnut allergy: Systematic literature review and meta-analysis

BACKGROUND

Hazelnut-specific IgE antibodies (sIgEs) in serum support the diagnosis of hazelnut allergy, but extract-based tests have low diagnostic specificity, commonly leading to over-diagnosis. Measuring sensitization to individual allergen components may enhance the diagnosis of hazelnut allergy. We systematically examined data on diagnostic accuracy of sIgE to commercially available hazelnut components to compare their individual contributions in diagnosing hazelnut allergy.

METHODS

Seven databases were searched for diagnostic studies on patients suspected of having hazelnut allergy. Studies employing component-specific IgE testing on patients whose final diagnosis was determined by oral food challenges were included in the meta-analysis. Study quality was assessed as recommended by Cochrane.

RESULTS

Seven cross-sectional studies and one case-control study were identified, seven presenting data on children (N = 635), and one on a mixed age population. Overall, the diagnostic accuracies of sIgE to both Cor a 9 and Cor a 14 were significantly higher than for Cor a 1-sIgE (P < .05). In children, the specificity of Cor a 14-sIgE at 0.35 kU_A /L cutoff was 81.7% (95% CI 77.1, 85.6), and 67.3% (60.3, 73.6) for Cor a 9-sIgE. The specificities for Cor a 1-sIgE and hazelnut-sIgE were 22.5% (7.4, 51.2) and 10.8% (3.4, 29.8), respectively. The sensitivity of Cor a 1-sIgE (60.2% [46.9, 72.2]) was lower than for hazelnut extract-sIgE (95.7% [88.7, 98.5]), while their specificities did not differ significantly.

CONCLUSION

sIgE to Cor a 14 and Cor a 9 hazelnut storage proteins increases diagnostic specificity in assessing hazelnut allergy in children. The combined use of hazelnut extract and hazelnut storage proteins may improve diagnostic value.

Likely questionnaire-diagnosed food allergy in 78, 890 adults from the northern Netherlands

BACKGROUND

It is challenging to define likely food allergy (FA) in large populations which limited the number of large studies regarding risk factors for FA.

OBJECTIVE

We studied the prevalence and characteristics of self-reported FA (s-rFA) in the large, population-based Dutch Lifelines cohort and identified associated risk factors.

METHODS

Likely food allergic cases (LikelyFA) were classified based on questionnaire reported characteristics consistent with FA. Subjects with atypical characteristics were classified as Indeterminate. We investigated 13 potential risk factors for LikelyFA such as birth mode and living on a farm and addressed health-related quality of life (H-RQOL).

RESULTS

Of the 78, 890 subjects, 12.1% had s-rFA of which 4.0% and 8.1% were classified as LikelyFA and Indeterminate, respectively. Younger age, female sex, asthma, eczema and nasal allergy increased the risk of LikelyFA (p-value range <1.00*10-250-1.29*10-7). Living in a small city/large village or suburb during childhood was associated with a higher risk of LikelyFA than living on a farm (p-value = 7.81*10-4 and p = 4.84*10-4, respectively). Subjects classified as Indeterminate more often reported depression and burn-out compared to those without FA (p-value = 1.46*10-4 and p = 8.39*10-13, respectively). No association was found with ethnicity, (duration of) breastfeeding, birth mode and reported eating disorder. Mental and physical component scores measuring H-RQOL were lower in both those classified as LikelyFA and Indeterminate compared to those without FA.

CONCLUSION

The prevalence of s-rFA among adults is considerable and one-third reports characteristics consistent with LikelyFA. Living on a farm decreased the risk of LikelyFA. The association of poorer H-RQOL as well as depression and burn-out with questionable self-perceived FA is striking and a priority for future study.

Association of the STAT6 rs3024974 (C/T) Polymorphism with IgE-Mediated Food Sensitization among West Bengal Population in India

INTRODUCTION

Genetic polymorphisms associated with IgE-mediated food sensitization have been a robust area of research for decades. A genome-wide search for susceptible loci regulating the IgE response (atopy) identified the candidate gene STAT6, which is important in the context of food allergic manifestations.

OBJECTIVE

The present study was designed to investigate the sensitization of West Bengal population against some common allergenic food items and to study the role of the STAT6 gene polymorphism in elevating food-specific IgE levels among sensitized individuals.

METHODS

Skin prick test was performed for 6 food items among 501 patients (126 children, 85 adolescents, and 290 adults)from West Bengal, India. Among them, 165 patients were selected for measurement of total IgE and food-specific IgE levels along with 165 controls. Finally, the STAT6 (rs3024974 (C/T) polymorphism was genotyped in 139 cases and control subjects.

RESULTS

Shrimp was identified as a dominant food allergen in adolescents and adults, whereas milk sensitization was highest in children. Food-sensitized patients with onset during childhood had significantly higher total IgE levels compared to patients with onset during adulthood (p < 0.00001). The frequency of the rs3024974 CC genotype in both cases and control subjects (55.40 and 46.76%, respectively) was higher than that of CT or TT. Patients with childhood onset bearing the CC genotype had significantly higher specific IgE levels in comparison to those with adult onset (p = 0.001).

CONCLUSION

Food sensitization has a genetic background and the rs3024974 polymorphism is associated with susceptibility and reaction severity in food-sensitized patients in West Bengal population in India.

Cost-effectiveness of using an extensively hydrolyzed casein formula supplemented with Lactobacillus rhamnosus GG in managing IgE-mediated cow's milk protein allergy in the UK

Objective: To estimate the cost-effectiveness of using an extensively hydrolyzed casein formula (eHCF) plus the probiotic Lactobacillus rhamnosus GG (eHCF plus LGG; Nutramigen* LGG^®) compared to an eHCF alone as first-line dietary management for Immunoglobulin E (IgE)-mediated cow's milk protein allergy (CMPA) in the UK. Methods: Decision modelling was undertaken to estimate the probability of IgE-mediated cow's milk allergic infants being symptom free (i.e. not experiencing urticaria, eczema, asthma or rhinoconjunctivitis) and developing tolerance to cow's milk by 5 years. The model also estimated the cost (at 2016/2017 prices) of healthcare resource use funded by the UK's National Health Service (NHS) over 5 years after starting a formula, as well as the relative cost-effectiveness of the two dietary formulae. Results: At 5 years after the start of a formula the probability of being symptom free was estimated to be 0.97 and 0.76 among infants who were originally fed eHCF plus LGG and an eHCF alone, respectively. This encompassed the probability of children being asthma free at 5 years after the start of treatment, which was 0.99 and 0.91 in the eHCF plus LGG and eHCF alone groups, respectively. Additionally, the probability of acquiring tolerance to cow's milk was estimated to be 0.94 and 0.66 among infants who were originally fed eHCF plus LGG and an eHCF alone, respectively. The estimated total healthcare cost over 5 years of initially feeding infants with eHCF plus LGG was less than that of feeding infants with an eHCF alone (£4229 versus £5136 per patient). Conclusions: First-line management of newly diagnosed infants with IgE-mediated CMPA with eHCF plus LGG instead of an eHCF alone improves outcome, releases healthcare resources for alternative use, reduces the NHS cost of patient management and thereby affords a cost-effective dietetic strategy to the NHS.

Pollen-Food Allergy Syndrome: A not so Rare Disease in Childhood

Seasonal allergic rhinoconjunctivitis (SAR) affects millions of people worldwide, particularly in childhood and adolescence. Pollen food allergy syndrome (PFAS) is a common adverse reaction occurring few minutes after the consumption of vegetable foods in patients with pollen-induced SAR. PFAS has rarely been investigated in the pediatric population, as it has been mainly examined as an adult disease. Recent studies suggested that PFAS might be more frequent in childhood than previously recognized. The present review aims to give an overview of the epidemiology, pathophysiology, diagnosis, management and prognosis of PFAS in children with SAR-induced by pollens.

CONCENTRATIONS OF CYSTEINYL LEUKOTRIENES IN VARIOUS BIOLOGICAL FLUIDS OF CHILDREN WITH BRONCHIAL ASTHMA, ATOPIC DERMATITIS AND FOOD PROTEIN INDUCED ENTEROCOLITIS

Clinical manifestation of food allergy is characterized by polymorphic cutaneous, respiratory and gastrointestinal syndromes. Leukotrienes occupy a key place in the pathogenesis of a wide range of inflammatory diseases, including bronchial asthma, allergic rhinitis, atopic dermatitis, hives, allergic conjunctivitis, atherosclerotic cardio-vascular lesions system, inflammatory bowel disease, multiple sclerosis, cancer, etc. Better understanding of general pathophysiological mechanisms of allergic realization put the focus on the studying of cysteinyl leukotrienes biological effects in infants with atopic dermatitis and food-protein induced enterocolitis important. Aim. To optimize the diagnosis of allergic lesions of the gastrointestinal tract in children. Methods. The study was conducted in the allergy center and children clinic of the «Institute Pediatrics, Obstetrics and Gynecology named after academician O. Lukyanova of NAMS of Ukraine». Children were included from September 2017 to June 2018. We examined 60 patients aged from 3 months to 3 years old, including 22 patients with atopic dermatitis, 18 children with food-protein induced enterocolitis, 8 patients with bronchial asthma in the stage of aggravation and 12 practically healthy children (control group). Medical examination have been perfomed, general IG E and specific serum IG E were defined by ImmunoCAP (Phadia, 100), as well as concentrations of cysteinyl leukotrienes (LTB4, LTC4, LTE4) in biological liquids (serum, saliva, urine) using immunoenzyme method using the production sets of the "Enzolifescience" (USA) company on the analyzer-photometer Multiskan Plus "Labsystems". The results of the received data were processed statistically. The probability of differences was estimated with Student’s t-test and Tau Kendall rank correlation test. The difference was considered significant at p <0.05. Results. A significant increase in the concentrations of cysteinyl leukotrienes (C4, D4, E4) in the blood, urine and saliva was found in infants with allergic skin diseases, gastro-intestinal and respiratory tract surveyed during manifestation the disease compared with the control group. Comparison of concentrations of leukotrienes in urine and saliva of children with atopic dermatitis (AD), food-protein induced enterocolitis (FPIE) and asthma did not find credible. However, in the serum of patients with asthma, the concentration of cysteinyl leukotrienes was significantly higher (703.9±68.7) pg / ml than in children with enterocolitis induced by dietary proteins (509.3±57.4) pg / ml and significantly did not differ from patients with atopic dermatitis (695.2±46.3) pg / ml. According to the results of Kendall Tau correlation test, no significant Spearman rank correlation was found between the cysteinyl leukotrienes concentration in blood and urine – r=0.14 (p>0.05), blood and saliva r=0.07 (p>0.05), urine and saliva r=–0.52 (p>0.05). Conclusions. Increase in cysteinyl leukotrienes concentrations in serum, urine and saliva of children of early age with allergic skin diseases, respiratory and gastrointestinal tract was found. The absence of significant Spearman rank correlation between concentrations of leukotrienes in blood and urine, blood and saliva, saliva and urine shows that it is possible to select any biological fluid, saliva or urine, as a non-invasive way to determine the leukotriene concentrations for monitoring activity of allergic inflammation.

Prevalence of food allergy among schoolchildren in Kuwait and its association with the coexistence and severity of asthma, rhinitis, and eczema: A cross-sectional study

BACKGROUND

Food allergy (FA) is a common public health problem that affects both children and adults. Empirical knowledge of the burden of FA in Kuwait is limited. This study sought to estimate the prevalence of FA among schoolchildren in Kuwait and assess associations between FA and the coexistence and severity of asthma, rhinitis, and eczema.

METHODS

Schoolchildren aged 11-14 years (n = 3,864) were enrolled in a cross-sectional study. Parents completed questionnaires regarding their children's early life exposures and clinical history of FA and allergic diseases. Study-defined FA was ascertained by a convincing clinical history. Associations were assessed using Poisson regression with robust variance estimation, and adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs) were estimated.

RESULTS

The 12-month prevalence of study-defined FA was estimated to be 4.1% (154/3,738), with more girls being affected than boys (aPR = 1.44, 95% CI: 1.04-1.99). Egg (2.7%), fish (1.6%), shellfish (1.3%), peanut (1.3%), and tree nut (1.2%) were the most reported offending food allergens. Underweight and adiposity, cesarean section delivery, exposure to household dogs during infancy, and parental history of doctor-diagnosed FA were associated with an increased prevalence of study-defined FA. However, later birth order was associated with a reduced prevalence of study-defined FA. The prevalence of eczema only was higher in children with study-defined FA than in those without study-defined FA (aPR = 3.49, 95% CI: 2.37-5.14). In contrast, this association was not pronounced for children who had asthma only (aPR = 1.56, 95% CI: 0.94-2.57) or rhinitis only (aPR = 1.40, 95% CI: 0.86-2.28). Study-defined FA was associated with a 9.20-fold (95% CI: 4.50-18.78) higher prevalence of coexisting asthma, rhinitis, and eczema. Moreover, study-defined FA was associated with increased severity of symptoms of asthma, rhinitis, and eczema.

CONCLUSIONS

FA affects a considerable proportion of schoolchildren in Kuwait, and the most reported offending food allergens are similar to those reported in Western countries. Study-defined FA was associated with the coexistence and increased severity of asthma, rhinitis, and eczema, indicating that FA may link the comanifestations of allergic diseases and contribute to their chronicity and severity.