New visions for food allergy: an iPAC summary and future trends

Prevalence of Parent-Reported Food Allergies and Associated Risk Predictors Among Children in Saudi Arabia

BACKGROUND AND OBJECTIVE

The worldwide prevalence of food allergies has been increasing recently. Due to limited data on food allergy (FA) in Saudi Arabia, this study was conducted to estimate the prevalence and risk factors of parent-reported food allergies and clinical manifestations in children in Taif, Saudi Arabia.

METHODOLOGY

A cross-sectional questionnaire-based observational study was conducted from July 2019 to December 2020. A total of 508 parents of school children (aged five to eight years) responded to the questions based on the child's health and food allergies.

RESULTS

FA (16.1%) was observed as the most common type of allergy among children. The prevalence of other atopic diseases was estimated at 30.5%. The most common allergy-causing foods were eggs (4.9%), peanuts (2.7%), and sesame (2.5%). Rash, itching without rash, and vomiting were the most common FA symptoms. The presence of childhood eczema (p< 0.0001), allergic rhinitis (p= 0.005), and the father's history of allergy (p= 0.005) were all significant and independent predictors/risk factors for FA among the studied children.

CONCLUSION

We noted substantial parents' concern with food allergies among children in Saudi Arabia, which necessitates the establishment of effective diagnosis and treatment strategies and primary prevention initiatives.

Managing Cow's Milk Protein Allergy with an Extensively Hydrolyzed Formula: Results from a Prospective, Non-Interventional Study in France (EVA Study)

Symptoms related cow’s milk proteins allergy (CMPA) usually improve between two to four weeks following an elimination diet, firstly with extensively hydrolyzed formulas (eHF). The aim of the EVA study was to observe the evolution of CMPA-related symptoms in real life after initiation of a whey-based extensively hydrolyzed formula (w-eHF, Althéra®, Nestlé Health Science, Switzerland). This cross-sectional prospective non-interventional study was carried out alongside paediatricians in private practice in France between June 2019 and June 2020. Infants aged 0−3 years presenting with confirmed diagnosis or clinical symptoms suggesting CMPA were enrolled. Data were collected at enrolment (baseline visit) and three to five weeks later (follow-up visit). Symptoms were assessed using the Cow’s Milk-related Symptom Score (CoMiSS®). The per protocol population included 135 infants. The average number of symptoms per infant significantly decreased under the study formula (from 2.81 to 1.36, p < 0.001) and the proportions of infants with any CMPA related symptoms decreased. Daily crying and regurgitation showed the largest decline, respectively −44.4% and −31.85% (p < 0.001). These results describe the early management of symptoms suspected to be related to CMPA in routine practice that was rarely described in the literature. The number and severity of symptoms decreased most of the cases after commencing the study formula.

IgE and mast cells: The endogenous adjuvant

Mast cells and IgE are most familiar as the effectors of type I hypersensitivity reactions including anaphylaxis. It is becoming clear however that this pair has important immunomodulatory effects on innate and adaptive cells of the immune system. In this purview, they act as endogenous adjuvants to ignite evolving immune responses, promote the transition of allergic disease into chronic illness and disrupt the development of active mechanisms of tolerance to ingested foods. Suppression of IgE-mediated mast cell activation can be exerted by molecules targeting IgE, FcɛRI or signaling kinases including Syk, or by IgG antibodies acting via inhibitory Fcγ receptors. In 2015 we reviewed the evidence for the adjuvant functions of mast cells. This update includes the original text, incorporates some important developments in the field over the past five years and discusses how interventions targeting these pathways might have promise in the development of strategies to treat allergic disease.

Oral immunotherapy with omalizumab reverses the Th2 cell-like programme of regulatory T cells and restores their function

BACKGROUND

Oral immunotherapy (OIT) successfully desensitizes patients with food allergies, but the immune mechanisms mediating its efficacy remain obscure.

OBJECTIVES

We tested the hypothesis that allergen-specific regulatory T (Treg) cell function is impaired in food allergy and is restored by anti-IgE antibody (omalizumab)-supplemented OIT.

METHODS

Peanut-specific T effector (Teff) and Treg cell proliferative responses, activation markers and cytokine expression were analysed by flow cytometry in 13 peanut-allergic subjects before the start of omalizumab-supplemented OIT and periodically in some subjects thereafter for up to 2 years. Peripheral blood regulatory T cells (Treg cells) were analysed for their peanut-specific suppressor function before and at 1 year following OIT. This study was registered on ClinicalTrials.gov (NCT01290913).

RESULTS

Proliferation of allergen-specific Teff and Treg cells precipitously declined following the initiation of omalizumab therapy prior to OIT, followed by partial recovery after the initiation of OIT. At baseline, peanut-specific Treg cells exhibited a Th2 cell-like phenotype, characterized by increased IL-4 expression, which progressively reversed upon OIT. Peanut-specific Treg cell suppressor activity was absent at the start of omalizumab/OIT therapy but became robust following OIT. Absent peanut-specific Treg cell function could also be recovered by the acute blockade of IL-4/IL-4R receptor signalling in Treg cells, which inhibited their IL-4 production.

CONCLUSIONS AND CLINICAL RELEVANCE

OIT supplemented by omalizumab promotes allergen desensitization through an initial omalizumab-dependent step that acutely depletes allergen-reactive T cells, followed by an increase in allergen-specific Treg cell activity due to the reversal of their Th2 cell-like programme. Improved Treg cell function may be a key mechanism by which OIT ameliorates food allergy.

The diagnosis and management of food allergies. Position paper of the Food Allergy Section the Polish Society of Allergology

The paper concerns the current position of the Polish Society of Allergology Food Allergy Section on the diagnosis and management of food allergies. The aim of this position is to provide evidence-based recommendations on the diagnosis and management of patients with allergic hypersensitivity to foods. This position statement includes a systematic review of studies in three areas, namely, the epidemiology, diagnosis and management of food allergies. While taking into account the specific Polish setting, in this publication we also used the current European Academy of Allergy and Clinical Immunology (EAACI) position paper and other current position statements, including those of the United States National Institute of Allergy and Infectious Diseases (NIAID).

Protein-losing enteropathy and erythema caused by egg allergy in a breast-fed infant

A 4-month-old breast-fed girl presented with poor weight gain, and had edema and repeated erythema from 5 months of age. The diagnosis of protein-losing enteropathy (PLE) was confirmed on ^99m Tc-labeled human serum albumin scintigraphy. Specific IgE radioallergosorbent test was class 3 for egg white, class 2 for egg yolk, and negative for other foods. Elimination of egg from the mother's diet and oral epinastine hydrochloride treatment and sodium cromolyn improved hypoalbuminemia, hypogammaglobulinemia, and erythema. PLE and erythema coincident in a breast-fed infant suggests that IgE-mediated allergy may play a leading role in some cases of PLE due to food allergy in infants.

Diagnosis and treatment of pediatric food allergy: an update

The prevalence of pediatric food allergy and anaphylaxis has increased in the last decades, especially in westernized countries where this emerging phenomenon was marked as a "second wave" of the allergic epidemic. Over recent years great advances have been achieved in the field of in vitro allergy testing and component-resolved diagnosis has increasingly entered clinical practice. Testing for allergen components can contribute to a more precise diagnosis by discriminating primary from cross-reactive sensitizations and assessing the risk of severe allergic reactions.The basic concept of the management of food allergy in children is also changing. Avoidance of the offending food is still the mainstay for disease management, especially in primary health care settings, but it severely affects the patients' quality of life without reducing the risk of accidental allergic reactions. There is a growing body of evidence to show that specific oral tolerance induction can represent a promising treatment option for food allergic patients. In parallel, education of food allergic patients and their caregivers as well as physicians about anaphylaxis and its treatment is becoming recognized a fundamental need. International guidelines have recently integrated these new evidences and their broad application all over Europe represents the new challenge for food allergy specialists.

The history of pediatric allergy in Europe - from a working group to ESPACI and SP-EAACI

A Working Group on Pediatric Allergology was formed in 1984, which rapidly developed to become the European Society on Pediatric Allergology and Clinical Immunology (ESPACI) in 1988 with its own journal, Pediatric Allergology and Immunology. ESPACI worked together with the European Academy of Allergology and Clinical Immunology (EAACI) to form a Section of Pediatrics within EAACI (SP-EAACI) in 1996. The ESPACI and the SP-EAACI formally merged in 2001. Within the EAACI organization, the Pediatric Section has continued to grow. The Pediatric Section is working to develop pediatric allergology across Europe, focusing on postgraduate education, facilitating the research agenda and advocating for children and adolescents with allergies.

A microbiota signature associated with experimental food allergy promotes allergic sensitization and anaphylaxis

BACKGROUND

Commensal microbiota play a critical role in maintaining oral tolerance. The effect of food allergy on the gut microbial ecology remains unknown.

OBJECTIVE

We sought to establish the composition of the gut microbiota in experimental food allergy and its role in disease pathogenesis.

METHODS

Food allergy-prone mice with a gain-of-function mutation in the IL-4 receptor α chain (Il4raF709) and wild-type (WT) control animals were subjected to oral sensitization with chicken egg ovalbumin (OVA). Enforced tolerance was achieved by using allergen-specific regulatory T (Treg) cells. Community structure analysis of gut microbiota was performed by using a high-density 16S rDNA oligonucleotide microarrays (PhyloChip) and massively parallel pyrosequencing of 16S rDNA amplicons.

RESULTS

OVA-sensitized Il4raF709 mice exhibited a specific microbiota signature characterized by coordinate changes in the abundance of taxa of several bacterial families, including the Lachnospiraceae, Lactobacillaceae, Rikenellaceae, and Porphyromonadaceae. This signature was not shared by similarly sensitized WT mice, which did not exhibit an OVA-induced allergic response. Treatment of OVA-sensitized Il4raF709 mice with OVA-specific Treg cells led to a distinct tolerance-associated signature coincident with the suppression of the allergic response. The microbiota of allergen-sensitized Il4raF709 mice differentially promoted OVA-specific IgE responses and anaphylaxis when reconstituted in WT germ-free mice.

CONCLUSION

Mice with food allergy exhibit a specific gut microbiota signature capable of transmitting disease susceptibility and subject to reprogramming by enforced tolerance. Disease-associated microbiota may thus play a pathogenic role in food allergy.

Severe reaction in a child with asymptomatic codfish allergy: food challenge reactivating recurrent pancreatitis

An 8-year-old child during the first year of life manifested severe atopic dermatitis and chronic diarrhea with mucorrhea and rectal bleeding; a fish-free diet was started based on weakly positive skin-prick tests to codfish extract. At the age of 4 years the child began to suffer of recurrent pancreatitis. When he came to our attention for the evaluation of his fish allergy, he was asymptomatic; a weak reactivity to codfish was observed (SPTs: cod, 4 mm, sIgE ImmunoCAP: cod, 1.30kU/l). The food challenge test with cod was negative. When the child ate cod again, within 5 minutes, developed anaphylactic reaction and complained of abdominal pain compatible with pancreatitis (enzyme serum levels risen and parenchymal oedema at ultrasonography), that resolved within 7 days after specific therapy. This case raises two issues: the elimination diet in asymptomatic food allergy on the basis only of SPT and the ethicality of food challenge in gastrointestinal chronic disease.

Real-life epidemiology of food allergy testing in Finnish children

BACKGROUND

The cumulative incidence of parental-reported symptoms of food allergy (FA) during the first years of life is estimated to exceed 30%. However, the occurrence and determinants of FA testing in a general child population have remained unknown.

METHODS

The study population comprised all 5920 children aged 0-4 yr in the province of South Karelia, Finland, identified from the nationwide population register. The study included a questionnaire survey and a retrospective collection of FA test results (skin prick tests, IgE antibodies, or open food challenges) from the patient records of the entire study population. The questionnaire and patient record data were linked together on an individual basis with the parents' permission.

RESULTS

A total of 5849 FA tests had been performed on 961 children. By the age of 4 yr, the cumulative incidence of FA testing was 18% for any food item; 17% for essential items (milk, egg, cereals) and 9% for other food items. Essential food items had been tested in 90% of children who reportedly had a physician-diagnosed FA for these. The incidence of testing was 30% higher in boys than in girls and twofold higher among the offspring whose either or both parents reportedly had some allergic manifestation.

CONCLUSIONS

A large proportion of children are subjected to FA testing in their early years. This result shows the need to evaluate the financial burden of FA testing and to improve current testing practices.

SKARP - A population-based cohort study of childhood food-associated symptoms perceived by parents and food allergies diagnosed by physicians: Design, methods and participation

Background: Few epidemiological studies exist on food-associated symptoms and allergies in large unselected child populations. Aims: To describe the design, methods and participation rate of the South Karelian Allergy Research Project (SKARP), a population-based epidemiological study on food-associated symptoms and physician-diagnosed food allergies. Methods: The study population of 5,973 children born between 2001 and 2006 and resident in the province of South Karelia, Finland, was identified from the nationwide population register. The parents received a questionnaire to be returned at their child’s annual visit to the child health clinic, where supplementary interviews were performed. Results of allergy tests (skin prick tests, immunoglobulin E antibodies and open food challenges) performed on participants and non-participants were collected from the relevant health care units in the area. Results: Participation rates in the questionnaire study were 54% (644/1,194) among the parents of neonates and 69% (3308/4,779) among those of the children aged 1 to 4 years. Cooperation with the child health clinics and mailing of a reminder questionnaire improved participation by 8 and 10 percentage points, respectively. The final participation rate seemed to be unaffected by whether the child had or had not been tested for suspected allergy. Conclusions: A reasonably good participation rate and almost complete coverage of allergy tests were achieved thanks to successful cooperation with the child health clinics and test laboratories. This baseline study forms a representative database to estimate the occurrence of food-associated symptoms, physician-diagnosed food allergies and allergy testing in the general population.

IgE-mediated systemic anaphylaxis and impaired tolerance to food antigens in mice with enhanced IL-4 receptor signaling

BACKGROUND

In atopic subjects food ingestion drives the production of IgE antibodies that can trigger hypersensitivity reactions. The IL-4 pathway plays a critical role in this response, and genetic polymorphisms in its components have been linked to allergy.

OBJECTIVE

We sought to test whether an activating mutation in the IL-4 receptor (IL-4R) α chain enhances allergic responses to a food antigen.

METHODS

F709 mice, in which the IL-4Rα immunoreceptor tyrosine-based inhibitory motif is inactivated, were gavage fed with ovalbumin (OVA). Reactions to OVA challenge and immune responses, including antibody production and T(H)2 responses, were assessed.

RESULTS

F709 mice, but not wild-type control animals, sensitized by means of gavage with OVA and either cholera toxin or staphylococcal enterotoxin B, displayed mast cell activation and systemic anaphylaxis on enteral challenge. Anaphylaxis was elicited even in F709 mice enterally sensitized with OVA alone. Bone marrow chimera experiments established that the increased sensitivity conferred by the F709 genotype was mediated mostly by hematopoietic cells but that nonhematopoietic cells also contributed. F709 mice exhibited increased intestinal permeability to macromolecules. The F709 genotype conferred increased OVA-specific IgE but not IgG1 responses, local and systemic T(H)2 responses, and intestinal mast cell hyperplasia compared with wild-type mice. Anaphylaxis was abrogated in F709 mice lacking IgE or the high-affinity receptor for IgE (FcεRI).

CONCLUSION

Augmented IL-4Rα signaling confers increased intestinal permeability and dramatically enhanced sensitivity to food allergens. Unlike anaphylaxis to injected antigens, which in rodents can be mediated by either IgE or IgG antibodies, the food-induced response in F709 mice is solely IgE dependent.

Immunoglobulin E-mediated food allergies among adults with allergic rhinitis

OBJECTIVE: To compare the prevalence of food allergy for peanut, shrimp, and milk in adults with allergic rhinitis and to determine predictive values of these allergens and total immunoglobulin E (IgE) to detect food allergies.

STUDY DESIGN: Cross-sectional study.

SETTING: University of Chicago Medical Center, Chicago, Illinois.

SUBJECTS AND METHODS: We retrospectively analyzed in vitro enzyme-linked immunosorbent assays of adults with rhinitis. Subjects were tested for nine inhalants and three foods (peanut, shrimp, milk) and total IgE. Subjects with food allergy history were tested with additional foods. The sensitivity (SE), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) of the allergens and total IgE to detect food allergies were calculated.

RESULTS: A total of 283 subjects received in vitro tests. Fortyone percent tested negative and 59 percent tested positive for inhalants. The prevalence of subjects with a positive peanut or shrimp allergy in the inhalant-positive population was significantly greater than subjects with milk allergy (23.4% peanut [ P = 0.008], 22.2% shrimp [ P = 0.001], and 13.2% milk [ P = 0.008], P = 0.001). For subjects with food allergy history, peanut had the best SP (100.0%), SE (28.1%), PPV (100.0%), and NPV (64.6%) in detecting allergies to other foods. In patients positive for the initial panel (inhalants and peanut), the SP, SE, PPV, and NPV of elevated total IgE was 71.4, 72.4, 77.8, and 65.2 percent, respectively.

CONCLUSION: Peanut and shrimp were the most common foods encountered in adults with allergic rhinitis. Peanut was best in predicting other food allergies. Total IgE levels with inhalants plus peanut provided the optimal combination of SE, SP, PPV, and NPV. In vitro testing may be important to identify and prevent anaphylaxis to foods in adults.

© 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Food allergy: separating the science from the mythology

Numerous genes are involved in innate and adaptive immunity and these have been modified over millions of years. During this evolution, the mucosal immune system has developed two anti-inflammatory strategies: immune exclusion by the use of secretory antibodies to control epithelial colonization of microorganisms and to inhibit the penetration of potentially harmful agents; and immunosuppression to counteract local and peripheral hypersensitivity against innocuous antigens, such as food proteins. The latter strategy is called oral tolerance when induced via the gut. Homeostatic mechanisms also dampen immune responses to commensal bacteria. The mucosal epithelial barrier and immunoregulatory network are poorly developed in newborns. The perinatal period is, therefore, critical with regard to the induction of food allergy. The development of immune homeostasis depends on windows of opportunity during which innate and adaptive immunity are coordinated by antigen-presenting cells. The function of these cells is not only orchestrated by microbial products but also by dietary constituents, including vitamin A and lipids, such as polyunsaturated omega-3 fatty acids. These factors may in various ways exert beneficial effects on the immunophenotype of the infant. The same is true for breast milk, which provides immune-inducing factors and secretory immunoglobulin A, which reinforces the gut epithelial barrier. It is not easy to dissect the immunoregulatory network and identify variables that lead to food allergy. This Review discusses efforts to this end and outlines the scientific basis for future food allergy prevention.

Evaluation of treatment satisfaction in children with allergic disease treated with an antihistamine: an international, non-interventional, retrospective study

BACKGROUND AND OBJECTIVES

Histamine H(1)-receptor antagonists (antihistamines) have been shown to be efficacious and safe in children and are recommended as first-line treatment for the symptoms of allergic rhinitis and urticaria. No published study to date has directly compared satisfaction with the different antihistamines in children in a real-life clinical setting. This study aimed to investigate parent and physician satisfaction with the efficacy and tolerability of oral antihistamine treatment in children and to compare satisfaction between levocetirizine and the other antihistamines used by children in this cohort.

METHODS

This was an international Observational Survey in Children with Allergic Rhinitis (OSCAR). Children aged 2-12 years, with a history of an allergic condition leading to a consultation, were enrolled from 424 primary-care/specialist allergy clinics across Bulgaria, India, Portugal, Romania, Russia, South Korea and Spain. At the consultation, parents and physicians of eligible children completed questionnaires evaluating their satisfaction with specific antihistamines currently employed for management of the child's allergic condition, as well as their intention for future use of that treatment. Parents' satisfaction scores for efficacy, tolerability and global satisfaction with the antihistamine used were primary study outcomes, while physicians' satisfaction scores for the same measures were secondary outcomes. Other secondary outcomes were parents' rating of the impact of the antihistamine treatment on their child's sleep and school performance, and parents' and physicians' willingness to use/recommend the same antihistamine in the future.

RESULTS

A total of 4581 patients were enrolled; 3048 (66.5%) had allergic rhinitis (55.9% persistent allergic rhinitis and 44.1% intermittent allergic rhinitis), and 663 (14.5%) had urticaria as primary conditions. Additionally, 2465 patients (53.8%) suffered from other allergic diseases, including allergic asthma (33.3%), atopic dermatitis (17.6%), food allergy (5.3%), other allergies (5.0%) and drug hypersensitivity (2.0%). Parents' and physicians' satisfaction scores were closely concordant and demonstrated significantly greater global satisfaction for the second-generation antihistamines than for the first-generation antihistamines. Levocetirizine (n = 2339) and fexofenadine (n = 42) generally scored highest for efficacy, tolerability and global satisfaction, as well as for impact on the child's ability to function at school, quality of school activities and quality of sleep. Furthermore, >97% of parents and physicians indicated their desire to continue or recommend the use of levocetirizine in the future. Somnolence, the most commonly reported adverse event in this survey, was observed predominantly in patients treated with first-generation antihistamines. Among second-generation antihistamines, reports of somnolence were most frequent in the cetirizine group.

CONCLUSION

Second-generation antihistamines have a better risk:benefit ratio than first-generation antihistamines, indicating that the latter should be avoided or their use limited in children whenever possible. Levocetirizine and fexofenadine were perceived by parents and physicians to produce significantly higher treatment satisfaction than the majority of the other antihistamines with respect to overall efficacy and tolerability, and impact on the child's sleep and school activities. The newer antihistamine levocetirizine seems to be a preferred and appropriate future treatment choice for children with allergic diseases.

The immunologic basis for gastrointestinal food allergy

PURPOSE OF REVIEW

Food allergies are common in children, although rare in adults. They can be life threatening via anaphylaxis, especially to peanut, and cause distress to children and parents because of the disease itself, and then through the difficulty of pursuing a strict elimination diet. In parents/carers and adults, this has significant impact on quality of life. The purpose of this review is to determine the therapeutic potential and current treatments for these conditions by understanding and manipulating the immune response.

RECENT FINDINGS

The single largest change in attitude to food allergies has been the realization that delaying exposure to foods may be harmful in terms of immune sensitization. Instead, strategies aimed at early introduction of foods to induce oral tolerance are now being re-evaluated. At the same time, very encouraging results are being obtained in desensitizing allergic children via oral tolerance. The aim of this strategy is not necessarily to induce complete tolerance to foods in allergic children but to raise the threshold dose at which adverse events occur, to minimize reactions to trace amounts of allergens.

SUMMARY

Food allergies are now recognized as being a treatable component of the atopic march.

The role of diet in symptoms of irritable bowel syndrome in adults: a narrative review

This review summarizes what is known about the effect of diet on irritable bowel syndrome (IBS) symptoms emphasizing data from randomized, controlled clinical trials. Studies suggest that IBS symptoms in one quarter of patients may be caused or exacerbated by one or more dietary components. Recent studies indicate that a diet restricted in fermentable, poorly absorbed carbohydrates, including fructose, fructans (present in wheat and onions), sorbitol, and other sugar alcohols is beneficial, but confirmatory studies are needed. Despite a long history of enthusiastic use, fiber is marginally beneficial. Insoluble fiber may worsen symptoms. Some patients with IBS, especially those with constipation, will improve with increased intake of soluble fiber. Prebiotic fibers have not been adequately tested. Daily use of peppermint oil is effective in relieving IBS symptoms. The usefulness of probiotics in the form of foods such as live-culture yogurt and buttermilk for IBS symptoms is not established. In clinical practice, it is very difficult to establish that a patient's symptoms result from an adverse reaction to food. A double blind placebo-controlled food challenge is the most reliable method, but it is not suitable for routine clinical use. A modified exclusion diet and stepwise reintroduction of foods or trials of eliminating classes of food may be useful.