The EuroPrevall birth cohort study on food allergy: baseline characteristics of 12,000 newborns and their families from nine European countries

Assessment of exposure to secondhand tobacco smoke in Spain: A scoping review

INTRODUCTION

There is no consensus on the questions that should be included in questionnaires to properly ascertain exposure to secondhand tobacco smoke (SHS). The objective of this study is to analyze the questions included in studies which have assessed SHS exposure in Spain.

METHODS

A scoping review was performed, using PubMed, Embase and Web of Science databases, selecting original articles published in English and Spanish, across the period 2012-2021. We extracted data from each study regarding its design, target population, sample size or geographical scope; we also collected data regarding how studies dealt with exposure to SHS including assessment and intensity of SHS, exposure setting, geographical scope, and the verbatim questions used.

RESULTS

Finally, 75 studies were identified. In the 23 studies carried out in children, verbatim questions were included in 8 studies, and the setting most studied was the home. SHS exposure was assessed during pregnancy and postnatally by 8 studies, the verbatim questions used were described in 2 studies, being exposure ascertained at home and workplace. In the adult population, 14 of 44 studies described the verbatim questions; the setting most studied was the home. Verbatim questions varied among studies.

CONCLUSIONS

Questionnaire-based assessment of SHS exposure is highly heterogeneous, hindering comparability between studies. Therefore, it is necessary to set a standard questionnaire to assess exposure to SHS.

Epidemiology of Paediatric Italian Food Allergy: Results of the EPIFA study

Background

Updated epidemiologic data are important for defining effective public health strategies for pediatric food allergy (FA).

Objective

The Epidemiology of Paediatric Italian Food Allergy (EPIFA) study was designed to investigate the epidemiology of pediatric FA in one of the most heavily populated Italian regions.

Methods

A retrospective cohort study was performed in collaboration with family pediatricians aimed at investigating the epidemiology of Italian pediatric FA during 2009 to 2021. Family pediatricians in the Campania region were invited to use the Google Forms platform for online compilation of data forms. Data forms were reviewed by experienced pediatric allergists at the coordinating center.

Results

A total population of 105,151 subjects (aged 0-14 years) was screened during the study period. Data from 752 FA patients were evaluated. A progressive increase in FA incidence and prevalence was observed from 2009 to 2021, with a relative increase up to 34% and 113.6%, respectively, at the end of study period. The relative increase in FA prevalence was higher in the 0-3-year-old age group in the same study period (+120.8%). The most frequent allergens were cow's milk, hen's egg, and nuts.

Conclusion

The results of the EPIFA study showed an increase in pediatric FA incidence and prevalence from 2009 to 2021 in Italy. These results underline the necessity of new effective strategies for preventing and managing these conditions.

Sociodemographic inequities in food allergy: Insights on food allergy from birth cohorts

A large and growing corpus of epidemiologic studies suggests that the population-level burden of pediatric FA is not equitably distributed across major sociodemographic groups, including race, ethnicity, household income, parental educational attainment, and sex. As is the case for more extensively studied allergic disease states such as asthma and atopic dermatitis epidemiologic data suggest that FA may be more prevalent among certain populations experiencing lower socioeconomic status (SES), particularly those with specific racial and ethnic minority backgrounds living in highly urbanized regions. Emerging data also indicate that these patients may also experience more severe FA-related physical health, psychosocial, and economic outcomes relating to chronic disease management. However, many studies that have identified sociodemographic inequities in FA burden are limited by cross-sectional designs that are subject to numerous biases. Compared with cross-sectional study designs or cohorts established later in life, birth cohorts offer advantages relative to other study designs when investigators seek to understand causal relationships between exposures occurring during the prenatal or postnatal period and the atopic disease status of individuals later in life. Numerous birth cohorts have been established across recent decades, which include evaluation of food allergy-related outcomes, and a subset of these also have measured sociodemographic variables that, together, have the potential to shed light on the existence and possible etiology of sociodemographic inequities in food allergy. This manuscript reports the findings of a comprehensive survey of the current state of this birth cohort literature and draws insights into what is currently known, and what further information can potentially be gleaned from thoughtful examination and further follow-up of ongoing birth cohorts across the globe.

Feast for thought: A comprehensive review of food allergy 2021-2023

A review of the latest publications in food allergy over the past couple of years confirmed that food allergy is a major public health concern, affecting about 8% of children and 10% of adults in developed countries. The prevalence of food allergy varies around the world, with the increase being driven mainly by environmental factors, possibly together with genetic susceptibility to environmental changes. A precise diagnosis of food allergy is extremely important. Both new tests (eg, the basophil activation test) and improved optimization of information provided by existing tests (eg, the skin prick test and measurement of specific IgE level) can contribute to improving the accuracy and patients' comfort of food allergy diagnosis. Understanding the underlying immune mechanisms is fundamental to designing allergen-specific treatments that can be safe and effective in the long term. New discoveries of the immune response to food allergens, including T-cell and B-cell responses, have emerged. Novel therapeutic approaches are being trialed at various stages of development as attempts to allow for more active intervention to treat food allergy. Prevention is key to reducing the increase in prevalence. Early introduction of allergenic foods seems to be the most effective intervention, but others are being studied, and will, it is hoped, lead to modification of the epidemiologic trajectory of food allergy over time.

Targeting Food Allergy with Probiotics

The globally dramatic increase in food allergy prevalence and severity is demanding effective preventive and therapeutic strategies. Food allergy derives from a defect of immune tolerance mechanisms. Immune tolerance is modulated by gut microbiome composition and function, and gut microbiome dysbiosis has been associated with the development of food allergy. Selected probiotic strains could regulate immune tolerance mechanisms. The mechanisms are multiple and are still not completely defined. Increasing evidence is providing useful information on the choice of optimal bacterial species/strains, dosage, and timing for intervention. The increased knowledge on the crucial role played by postbiotic gut microbiome-derived metabolites, such as butyrate, is also opening the way to a post- biotic approach in the stimulation of immune tolerance.

Assessment of Selected Intestinal Permeability Markers in Children with Food Allergy Depending on the Type and Severity of Clinical Symptoms

Background: Food allergy (FA) has a broad range of symptoms, and clinical manifestations may concern several reactions from one system or organ. Aim: The aim of the study was to assess intestinal permeability (IP) based on the analysis of serum zonulin and bacterial lipopolysaccharides (LPS) levels in children with FA, taking into account the pathomechanism of immune reaction, clinical symptoms of FA and their severity. Material and methods: The study comprised 103 patients aged 7–60 months (median 34); 49 children with IgE-mediated allergy and 25 children with non-IgE-mediated allergy; the reference group comprised 29 children with functional gastrointestinal disorders. IP markers were determined using ELISA. Results: There was no correlation between the severity of clinical symptoms and the level of IP markers in children with FA. Zonulin and LPS levels were significantly higher in children with FA and gastrointestinal symptoms. Zonulin levels in the subgroup of children with non-IgE-mediated FA and gastrointestinal symptoms were significantly higher than in the subgroup of children with IgE-mediated FA and these symptoms. The level of LPS was significantly higher in the subgroup with IgE-mediated FA and atopic dermatitis. Conclusions: Zonulin and LPS levels were significantly higher in children with FA compared to children from the reference group. Zonulin levels were significantly higher in children with non-IgE-mediated FA than in children with IgE-mediated FA.

Effects of the Mediterranean Diet during pregnancy on the onset of allergy in at risk children: A study protocol of a multi-center, randomized- controlled, parallel groups, prospective trial (the PREMEDI study)

Introduction

Maternal diet during pregnancy has been linked to offspring allergy risk and it could represent a potential target for allergy prevention. The Mediterranean Diet (MD) is considered one of the healthiest dietary models. Randomized-controlled trials on the effect of MD in preventing pediatric allergic diseases are still needed.

Methods and analysis

The Mediterranean Diet during Pregnancy study (PREMEDI) will be a 9-month multi-center, randomized-controlled, parallel groups, prospective trial. Healthy women (20–35 years) at their first trimester of pregnancy at risk for atopy baby, will be randomly allocated to Group 1 (standard obstetrical and gynecological follow-up and nutritional counseling to promote MD) or Group 2 (standard obstetrical and gynecological follow-up alone). 138 mother-child pair per group will be needed to detect a reduction in cumulative incidence of ≥1 allergic disease at 24 months of age. The primary study aim will be the evaluation of the occurrence of allergic disorders in the first 24 months of life. The secondary aims will be the evaluation of maternal weight gain, pregnancy/perinatal complications, growth indices and occurrence of other chronic disorders, mother-child pair adherence to MD and gut microbiome features, breastfeeding duration and breast milk composition, epigenetic modulation of genes involved in immune system, and metabolic pathways in the offspring.

Ethics and dissemination

The study protocol has been approved by the Ethics Committee of the University of Naples Federico II (number 283/21) and it will be conducted in accordance with the Helsinki Declaration (Fortaleza revision, 2013), the Good Clinical Practice Standards (CPMP/ICH/135/95), the Italian Decree-Law 196/2003 regarding personal data and the European regulations on this subject. The study has been registered in the Clinical Trials Protocol Registration System.

Clinical trial registration

[http://clinicaltrials.gov], identifier [NCT05119868].

Food allergy in infants assessed in two German birth cohorts 10 years after the EuroPrevall Study

BACKGROUND

The prevalence of food allergies (FA) in children increased rapidly at the turn of the century. The EuroPrevall study identified Germany as a country with very high prevalence of FA at that time. Using two large German birth cohorts, we provide an update of the status quo 10 years later.

METHODS

KUNO Kids and Ulm SPATZ Health studies are two ongoing prospective birth cohorts. Information on FA was obtained by questionnaires at birth and after 6, 12, and 24 months. Univariable and multivariable logistic regression analyses were performed to investigate risk factors during pregnancy, birth, and early childhood.

RESULTS

In 1139 and 1006 children from KUNO Kids and SPATZ, the point prevalence of parent-reported FA symptoms at the ages of 1 and 2 years was 13.2% (95% CI: 11.2-15.2) and 13.9% (95% CI: 11.5-17.2) in KUNO Kids. Doctor's diagnosed FA at 1 and 2 years was 2.4% (95% CI: 1.6-3.4) and 2.7% (95% CI: 1.2-4.3) in KUNO Kids and 2.3% (95% CI: 1.3-3.6) and 3% (95% CI: 2.0-4.5) in SPATZ. Cow's milk and citrus fruits were most frequently suspected by parents to cause FA symptoms. Atopy in the child was associated with a higher frequency of FA at any time, whereas atopy in first-degree relatives was only associated with FA at year 1. Smoke exposure during pregnancy was a risk for FA at age 2.

CONCLUSION

The prevalence of food allergy seems to have plateaued in the last 10 years in Germany. FA is often suspected by parents but only rarely diagnosed by oral food challenge. Risk factor analysis may help to establish personalized health approaches.

Safety of Vitamin D Food Fortification and Supplementation: Evidence from Randomized Controlled Trials and Observational Studies

The safety considerations of food-based solutions for vitamin D deficiency prevention, such as fortification and supplementation, are critical. On the basis of collective data from 20 randomized controlled trials (RCTs) and 20 national healthy surveys, as well as prospective cohort studies (PCSs) across the ODIN project (“Food-based solutions for optimal vitamin D nutrition and health through the life cycle”, FP7-613977), we analyzed the potential safety issues arising from vitamin D intakes and/or supplementation. These adverse consequences included high serum 25-hydroxyvitamin D (S-25(OH)D) concentrations (>125 nmol/L), high serum calcium concentrations, and vitamin D intakes in excess of the tolerable upper intake levels (ULs). In the RCTs (n = 3353, with vitamin D doses from 5–175 µg/day), there were no reported adverse effects. The prevalence of high S-25(OH)D was <10% when vitamin D supplements were administered, and <0.1% for fortified foods. Elevated serum calcium was observed among <0.5% in both administration types. No ODIN RCT participants exceeded the age-specific ULs. In observational studies (n = 61,082), the prevalence of high 25(OH)D among children/adolescents, adults, and older adults was <0.3%, with no evidence of adverse effects. In conclusion, high S-25(OH)D concentrations >125 nmol/L were rare in the RCTs and PCSs, and no associated adverse effects were observed.

Primary and pollen-associated hazelnut allergy in school-aged children in Germany: A birth cohort study

BACKGROUND

Primary hazelnut allergy is a common cause of anaphylaxis in children, as compared to birch-pollen associated hazelnut allergy. Population-based data on hazelnut and concomitant birch-pollen allergy in children are lacking. We aimed to investigate the prevalence of primary and pollen-associated hazelnut allergy and sensitization profiles in school-aged children in Berlin, Germany.

METHODS

1570 newborn children were recruited in Berlin in 2005-2009. The school-age follow-up (2014-2017) was based on a standardized web-based parental questionnaire and clinical evaluation by a physician including skin prick tests, allergen specific immunoglobulin E serum tests and placebo-controlled double-blind oral food challenges, if indicated.

RESULTS

1004 children (63.9% response) participated in the school-age follow-up assessment (52.1% male). For 1.9% (n = 19, 95%-confidence interval 1.1%-2.9%) of children their parents reported hazelnut-allergic symptoms, for half of these to roasted hazelnut indicating primary hazelnut allergy. Symptoms of birch-pollen allergy were reported for 11.6% (n = 116 95%-CI 9.7%-13.7%) of the children. Both birch-pollen allergy and hazelnut allergy associated symptoms affected 0.6% (n = 6, 95%-CI 0.2%-1.3%) of children. Assessment of allergic sensitization was performed in 261 participants and showed that almost 20% of these children were sensitized to hazelnut, being the most frequent of all assessed food allergens, or birch-pollen, the majority to both.

CONCLUSIONS

Based on parental reports hazelnut-allergic symptoms were far less common than sensitization to hazelnut. This needs to be considered by physicians to avoid unnecessary changes in diet due to sensitization profiles only, especially when there is a co-sensitization to hazelnut and birch-pollen.

Prevalence and early-life risk factors of school-age allergic multimorbidity: The EuroPrevall-iFAAM birth cohort

Background

Coexistence of childhood asthma, eczema and allergic rhinitis is higher than can be expected by chance, suggesting a common mechanism. Data on allergic multimorbidity from a pan‐European, population‐based birth cohort study have been lacking. This study compares the prevalence and early‐life risk factors of these diseases in European primary school children.

Methods

In the prospective multicentre observational EuroPrevall‐iFAAM birth cohort study, we used standardized questionnaires on sociodemographics, medical history, parental allergies and lifestyle, and environmental exposures at birth, 12 and 24 months. At primary school age, parents answered ISAAC‐based questions on current asthma, rhinitis and eczema. Allergic multimorbidity was defined as the coexistence of at least two of these.

Results

From 10,563 children recruited at birth in 8 study centres, we included data from 5,572 children (mean age 8.2 years; 51.8% boys). Prevalence estimates were as follows: asthma, 8.1%; allergic rhinitis, 13.3%; and eczema, 12.0%. Allergic multimorbidity was seen in 7.0% of the whole cohort, ranging from 1.2% (Athens, Greece) to 10.9% (Madrid, Spain). Risk factors for allergic multimorbidity, identified with AICc, included family‐allergy‐score, odds ratio (OR) 1.50 (95% CI 1.32–1.70) per standard deviation; early‐life allergy symptoms, OR 2.72 (2.34–3.16) for each symptom; and caesarean birth, OR 1.35 (1.04–1.76). Female gender, OR 0.72 (0.58–0.90); older siblings, OR 0.79 (0.63–0.99); and day care, OR 0.81 (0.63–1.06) were protective factors.

Conclusion

Allergic multimorbidity should be regarded as an important chronic childhood disease in Europe. Some of the associated early‐life factors are modifiable and may be considered for prevention strategies.

Changes in epidemiology and clinical practice in IgE-mediated Allergy in children

In the last decades, allergic diseases have increased exponentially and although pediatric asthma prevalence is stabilizing, it is estimated around 10% in Spain. Not the same with food allergy and anaphylaxis which are clearly increasing, becoming a significant public health problem. Taking into account epidemiological trends, the European Academy of Allergy and Clinical Immunology (EAACI) estimates that in less than 15 years more than half of the European population will suffer from some type of allergic disorder. The advances in diagnostic methods in food allergy, especially component resolved diagnosis, allow us to know the patient's sensitization profile and explain possible cross reactivity, anticipate potential risk of food trangressions, and prescribe correct avoidance diet in each patient. Thus, the development of molecular biology and nanotechnology have led to the appearance of new technologies (microarrays) which facilitate the study, specially of the polysensitized patients, allowing allergen immunotherapy (AIT) to be more personalized. The latest advances in the use of biologics are having an impact, not only in disease evolution, but also in quality of life.

[Changes in epidemiology and clinical practice in IgE-mediated allergy in children]

In the last decades, allergic diseases have increased exponentially and although pediatric asthma prevalence is stabilizing, in Spain is estimated around 10%. Not the same with food allergy and anaphylaxis which are clearly increasing, becoming a public health problem of the first magnitude. Considering epidemiological trends, the European Academy of Allergy and Clinical Immunology (EAACI) estimates that in less than 15 years more than half of European population will suffer from some type of allergy. The advances in diagnostic methods in food allergy, especially component resolved diagnosis, allow us to know the patient's sensitization profile and explain the possible cross reactivity, anticipate potential risk of food transgressions, and prescribe the correct avoidance diet in each patient. Thus, the development of molecular biology and nanotechnology have led to the appearance of new technologies (microarrays) which facilitate the study, specially of the polysensitized patients, allowing allergen immunotherapy (AIT) to be more personalized. The latest advances in the use of biologics are having an impact, not only in disease evolution, but also in patients quality of life.

The Impact of Formula Choice for the Management of Pediatric Cow's Milk Allergy on the Occurrence of Other Allergic Manifestations: The Atopic March Cohort Study

OBJECTIVES

To compare the impact of different formulas on the occurrence of other atopic manifestations and the time of immune tolerance acquisition.

STUDY DESIGN

In a 36-month prospective cohort study, the occurrence of other atopic manifestations (eczema, urticaria, asthma, and rhinoconjunctivitis) and the time of immune tolerance acquisition were comparatively evaluated in immunoglobulin E-mediated children with cow's milk allergy (CMA) treated with extensively hydrolyzed casein formula containing the probiotic L. rhamnosus GG (EHCF + LGG), rice hydrolyzed formula, soy formula, extensively hydrolyzed whey formula (EHWF), or amino acid-based formula.

RESULTS

In total, 365 subjects were enrolled into the study, 73 per formula cohort. The incidence of atopic manifestations was 0.22 (Bonferroni-corrected 95% CI 0.09-0.34) in the EHCF + LGG cohort; 0.52 (0.37-0.67) in the rice hydrolyzed formula cohort; 0.58 (0.43-0.72) in the soy formula cohort; 0.51 (0.36-0.66) in the EHWF cohort; and 0.77 (0.64-0.89) in the amino acid-based formula cohort. The incidence of atopic manifestations in the rice hydrolyzed formula, soy formula, EHWF, and amino acid-based formula cohorts vs the EHCF + LGG cohort was always greater than the prespecified absolute difference of 0.25 at an alpha-level of 0.0125, with corresponding risk ratios of 2.37 (1.46-3.86, P < .001) for rice hydrolyzed formula vs EHCF + LGG; 2.62 (1.63-4.22, P < .001) for soy formula vs EHCF + LGG; 2.31 (1.42-3.77, P < .001) for EHWF vs EHCF + LGG; and 3.50 (2.23-5.49, P < .001) for amino acid-based formula vs EHCF + LGG. The 36-month immune tolerance acquisition rate was greater in the EHCF + LGG cohort.

CONCLUSIONS

The use of EHCF + LGG for CMA treatment is associated with lower incidence of atopic manifestations and greater rate of immune tolerance acquisition.

Understanding Asthma and Allergies by the Lens of Biodiversity and Epigenetic Changes

Exposure to different organisms (bacteria, mold, virus, protozoan, helminths, among others) can induce epigenetic changes affecting the modulation of immune responses and consequently increasing the susceptibility to inflammatory diseases. Epigenomic regulatory features are highly affected during embryonic development and are responsible for the expression or repression of different genes associated with cell development and targeting/conducting immune responses. The well-known, "window of opportunity" that includes maternal and post-natal environmental exposures, which include maternal infections, microbiota, diet, drugs, and pollutant exposures are of fundamental importance to immune modulation and these events are almost always accompanied by epigenetic changes. Recently, it has been shown that these alterations could be involved in both risk and protection of allergic diseases through mechanisms, such as DNA methylation and histone modifications, which can enhance Th2 responses and maintain memory Th2 cells or decrease Treg cells differentiation. In addition, epigenetic changes may differ according to the microbial agent involved and may even influence different asthma or allergy phenotypes. In this review, we discuss how exposure to different organisms, including bacteria, viruses, and helminths can lead to epigenetic modulations and how this correlates with allergic diseases considering different genetic backgrounds of several ancestral populations.

IgE-reactivity profiles to allergen molecules in Russian children with and without symptoms of allergy revealed by micro-array analysis

BACKGROUND

The analysis of longitudinal birth cohorts with micro-arrayed allergen molecules has provided interesting information about the evolution of IgE sensitization in children. However, so far no cross-sectional study has been performed comparing IgE sensitization profiles in children with and without symptoms of allergy. Furthermore, no data are available regarding molecular IgE sensitization profiles in children from Russia.

METHODS

We recruited two groups of age- and gender-matched children, one (Group 1: n = 103; 12.24 ± 2.23 years; male/female: 58/45) with symptoms and a second (Group 2: n = 97; 12.78 ± 2.23 years; male/female: 53/44), without symptoms of allergy according to international ISAAC questionnaire. Children were further studied regarding symptoms of allergy (rhinitis, asthma, atopic dermatitis) according to international guidelines, and skin prick testing with a panel of aeroallergen extracts was performed before sera were analyzed in an investigator-blinded manner for IgE specific to more than 160 micro-arrayed allergen molecules using ImmunoCAP ISAC technology.

RESULTS

IgE sensitization = or >0.3 ISU to at least one of the micro-arrayed allergen molecules was found in 100% of the symptomatic children and in 36% of the asymptomatic children. Symptomatic and asymptomatic children showed a comparable IgE sensitization profile; however, frequencies of IgE sensitization and IgE levels to the individual allergen molecules were higher in the symptomatic children. Aeroallergen sensitization was dominated by sensitization to major birch pollen allergen, Bet v 1, and major cat allergen, Fel d 1. Food allergen sensitization was due to cross-sensitization to PR10 pollen and food allergens whereas genuine peanut sensitization was absent.

CONCLUSION

This is the first study analyzing molecular IgE sensitization profiles to more than 160 allergen molecules in children with and without symptoms of allergy. It detects similar molecular IgE sensitization profiles in symptomatic and asymptomatic children and identifies Bet v 1 and Fel d 1 as the predominant respiratory allergen molecules and PR10 proteins as the major food allergens and absence of genuine peanut allergy in Moscow region (Russia).

Early-onset-early-resolving atopic dermatitis does not increase the risk of development of allergic diseases at 3 Years old

BACKGROUND

Epidemiological findings showed the increased risk of allergic rhinitis (AR) and asthma in the children with preceding atopic dermatitis (AD). In this study, we aimed to observe the development of allergic diseases in infantile AD patients.

METHODS

We followed up the prospective observational cohort enrolling two-to four-month-old exclusively breastfed infants. The presence of physician-diagnosed asthma, AR and AD at age 3 was recorded with the laboratory tests for atopic sensitization.

RESULTS

Fifty infantile AD patients and 48 healthy controls were enrolled. The sex, age and parental atopy history were not significantly different between the two groups. At age 3, 21 (42%) patients had persistent AD in the infantile AD group while only 2 (4.2%) patients had newly diagnosed AD in the control group (p < 0.001). The early-onset-early-resolving AD (subsides before age 2) did not increase the risk of AR and asthma development, and the sensitization to allergens. However, the early-onset-persistent AD (persists after age 2) increased the risk of AR development and sensitization to inhalant allergens (adjusted odds ratio 2.83, 7.07, respectively). The parental atopy status was associated with any allergic disease at age 3 (p = 0.020). The maternal atopy history was the significant factor associated with AD, AR and eosinophilia at age 3 (p = 0.004, 0.014, 0.031, respectively).

CONCLUSION

The early-onset-early-resolving AD was not associated with allergic diseases development at age 3. The parental atopy history and early-onset-persistent AD might be the risk factors for development of allergic diseases at age 3.

Frequency of food allergy in school-aged children in eight European countries-The EuroPrevall-iFAAM birth cohort

BACKGROUND

The prevalence of food allergy (FA) among European school children is poorly defined. Estimates have commonly been based on parent-reported symptoms. We aimed to estimate the frequency of FA and sensitization against food allergens in primary school children in eight European countries.

METHODS

A follow-up assessment at age 6-10 years of a multicentre European birth cohort based was undertaken using an online parental questionnaire, clinical visits including structured interviews and skin prick tests (SPT). Children with suspected FA were scheduled for double-blind, placebo-controlled oral food challenges (DBPCFC).

RESULTS

A total of 6105 children participated in this school-age follow-up (57.8% of 10 563 recruited at birth). For 982 of 6069 children (16.2%), parents reported adverse reactions after food consumption in the online questionnaire. Of 2288 children with parental face-to-face interviews and/or skin prick testing, 238 (10.4%) were eligible for a DBPCFC. Sixty-three foods were challenge-tested in 46 children. Twenty food challenges were positive in 17 children, including seven to hazelnut and three to peanut. Another seventy-one children were estimated to suffer FA among those who were eligible but refused DBPCFC. This yielded prevalence estimates for FA in school age between 1.4% (88 related to all 6105 participants of this follow-up) and 3.8% (88 related to 2289 with completed eligibility assessment).

INTERPRETATION

In primary school children in eight European countries, the prevalence of FA was lower than expected even though parents of this cohort have become especially aware of allergic reactions to food. There was moderate variation between centres hampering valid regional comparisons.

Prevalence and clinical features of adverse food reactions in Portuguese adolescents

Background & aims

The objective of the present study was to determine, for the first time, the prevalence and clinical features of food allergy in Portuguese adolescents.

Methods

Cross-sectional study performed in various secondary schools in central Portugal. Randomly selected adolescents replied to a validated food allergy questionnaire. Those who reported an adverse food reaction were seen at participating hospitals, where clinical history was taken, skin prick (SPT) and prick-prick skin (SPPT) tests were performed, and food allergen-specific IgE levels (sIgE) were determined. An open oral challenge was performed in selected cases. Cases of positive clinical history of immediate (up to 2 h after ingestion) reaction in association with positive food sIgE levels and/or SPT were classified as IgE-associated probable food allergy and as confirmed IgE-mediated food allergy if food challenges were positive. Cases of positive clinical history of delayed (more than 2 h after ingestion) and negative food sIgE levels independently of positive SPT or SPPT results, were classified as non-IgE associated probable food allergy.

Results

The prevalence of probable food allergy in Portuguese adolescents was 1.41% (95% CI: 0.90–2.03%), with fresh fruits, shellfish, nuts, and peanut as the most frequently implicated foods. IgE-mediated probable food allergy occurred in 1.23% (95% CI: 0.67–1.72%) of cases, with fresh fruits, shellfish, and nuts mainly involved. Cutaneous symptoms were most frequently reported.

Conclusions

The prevalence of probable food allergies in Portuguese adolescents is low, is mostly related to fresh fruits, shellfish, nuts, and peanut, and most frequently involves cutaneous symptoms.

Late introduction of solids into infants' diets may increase the risk of food allergy development

Background

This study investigated risk factors associated with food allergy or food intolerance among school children in two Swedish towns.

Methods

Questionnaires were used to collect data on self-reported food allergy or intolerance (SRFA) in children aged 7–8 years from Mölndal in southwestern Sweden and Kiruna in northern Sweden. It included questions about specific food allergy or intolerance to cows’ milk, hens’ eggs, fish, peanuts, tree nuts, and cereals and also age of onset, type of symptoms and age of cessation. Information was also gathered on family allergy history, dietary habits, and certain lifestyle aspects.

Results

Of 1838 questionnaires distributed, 1029 were returned: 717/1354 (53%) from Mölndal and 312/484 (64%) from Kiruna. The cumulative incidence of SRFA was 19.6% with a significantly higher cumulative incidence in Kiruna (28.5%) than in Mölndal (15.7%), P < .001. Solids were introduced at a later age in Kiruna. Introduction of solids into a child’s diet from the age of 7 months or later, and maternal history of allergic disease, were both risk factors associated with a higher risk of food allergy or intolerance.

Conclusion

Late introduction of solids into an infant’s diet may be one risk factor for developing food allergy or intolerance. Later introduction of solids in Kiruna may be one explanation for the higher cumulative incidence of SRFA in that region.

Postbiotics: A novel strategy in food allergy treatment

During the last two decades, the prevalence and severity of clinical appearances of food allergy (FA) have a significant rise. FA derives from a breakdown of immune tolerance. In recent year's clinical evidence have shown that the probiotics have significant influences on FA by improving the immune tolerance. Besides, postbiotics due to their unique characteristics (safe profile, more shelf life, resistance to mammalian enzymes and stable to digestive system conditions), may have safety superiority against their parent live cells and as a novel strategy can be applied for improvement immune tolerance and treatment of FA without any undesirable side-effects or human opportunistic infections, particularly in infants and pediatrics.

Anaphylaxis diagnosis and management in the Emergency Department of a tertiary hospital in the Philippines

Background

In the Emergency Department (ED), diagnosis and management of anaphylaxis are challenging with at least 50% of anaphylaxis episodes misdiagnosed when the diagnostic criteria of current guidelines are not used.

Objective

Objective of our study was to assess anaphylaxis diagnosis and management in patients presenting to the ED.

Methods

Retrospective chart review conducted on patients presenting to The Medical City Hospital ED, the Philippines from 2013–2015 was done. Cases were identified based on International Statistical Classification of Diseases, 10th revision coding for either anaphylaxis or other allergic related diagnosis. Cases fitting the definition of anaphylaxis as identified by the National Institute of Allergy and Infectious Disease and the Food Allergy and Anaphylaxis Network (NIAID/FAAN) were included. Data collected included demographics, signs and symptoms, triggers and management.

Results

A total of 105 cases were evaluated. Incidence of anaphylaxis for the 3-year study period was 0.03%. Of the 105 cases, 35 (33%) were diagnosed as “urticaria” or “hypersensitivity reaction” despite fulfilling the NIAID/FAAN anaphylaxis criteria. There was a significant difference in epinephrine administration between those given the diagnosis of anaphylaxis versus misdiagnosed cases (61 [87%] vs. 12 [34%], χ² = 30.77, p < 0.01); and a significant difference in time interval from arrival at the ED to epinephrine administration, with those diagnosed as anaphylaxis (48%) receiving epinephrine within 10 minutes, versus ≥ 60 minutes for most of the misdiagnosed group (χ² = 52.97, p < 0.01).

Conclusion

Despite current guidelines, anaphylaxis is still misdiagnosed in the ED. Having an ED diagnosis of anaphylaxis significantly increases the likelihood of epinephrine administration, and at a shorter time interval.

Risk Factors for Hen's Egg Allergy in Europe: EuroPrevall Birth Cohort

BACKGROUND

Hen's egg is one of the commonest causes of food allergy, but there are little data on its risk factors.

OBJECTIVE

To assess the risk factors, particularly eczema, for hen's egg allergy in the EuroPrevall birth cohort.

METHODS

In the pan-European EuroPrevall birth cohort, questionnaires were undertaken at 12 and 24 months or when parents reported symptoms. Children with suspected egg allergy were invited for skin prick testing, specific IgE assessment, and double-blind, placebo-controlled food challenge (DBPCFC) as indicated. Each egg allergy case (positive DBPCFC or egg-induced anaphylaxis) was allocated up to 2 age- and country-matched controls.

RESULTS

A total of 12,049 infants were recruited into the EuroPrevall birth cohort, and 9,336 (77.5%) were followed until 2 years. A total of 86 infants had egg allergy (84 by DBPCFC) and were matched with 140 controls. Independently associated with egg allergy were past/current eczema (adjusted odds ratio, 9.21; 95% CI, 2.65-32.04), Scoring Atopic Dermatitis (1.54 per 5 units; 1.28-1.86), antibiotics in the first week of life (6.17; 1.42-26.89), and current rhinitis (3.02; 1.04-8.78). Increasing eczema severity was associated with an increasing likelihood of egg allergy. Eczema was reported to have started 3.6 (SE, 0.5) months before egg allergy. Age of introduction of egg into the diet was not associated with egg allergy.

CONCLUSIONS

Similar to peanut allergy, eczema was strongly associated with egg allergy development and the association increased with increasing eczema severity. The age of introduction of dietary egg was not a risk factor. The potential role of antibiotics in early life as a risk factor for egg allergy needs further examination.

Aeroallergen Exposure and Spread in the Modern Era

Since the initial discovery of aeroallergens in the 20th century, our understanding of their properties including sources and factors influencing their spread continues to expand. Both habits of daily living and the presence of environmental factors such as exposure to animals or pollution can influence susceptibility to atopic disease. Because relevant allergens may vary in individuals and communities, it is necessary to understand the physical properties of environmental aeroallergens that are associated with clinical disease to explain symptoms and to implement successful integrated interventions. The objective of this review was to present an overview of aeroallergens and the environmental factors influencing their current distribution. Using historical studies along with recent advancements, we will give an up-to-date description of the physical characteristics and aerodynamics of aeroallergens in addition to location, quantities, and timing of exposure.

Dog ownership at three months of age is associated with protection against food allergy

BACKGROUND

The prevention of food allergy is a key priority for reducing the burden of allergic disease. Environmental exposures modulate the risk of developing food allergy and some of this may be mediated by the infants' developing microbiome. However, the role of potentially protective environmental exposures, such as pet ownership, is largely uninvestigated with respect to food allergy.

METHODS

We performed a secondary cohort analysis in the Enquiring About Tolerance (EAT) study, which enrolled 1303 three-month infants onto a randomized trial to prevent food allergy. A survey elicited domestic animal ownership and participants were examined for atopic dermatitis (AD) at enrolment. Sensitization to foods and aeroallergens were elicited by skin and serum testing at 3, 12 and 36 months. Food allergy status was determined by double-blind placebo-controlled food challenges between 1 and 3 years.

RESULTS

Food allergy was diagnosed amongst 6.1% (68/1124) of participants with complete data. No significant relationships were demonstrated between food allergy and caesarean delivery, infections or antibiotic exposure in early life. After adjusting for familial atopic disease, maternal dog/cat sensitization and participant AD, living with dogs was associated with a 90% reduction in the odds of infants developing food allergy (adjusted odds ratio (aOR) 0.10 (confidence interval (CI) 0.01-0.71), P = 0.02). None of the 49 infants living with at least two dogs developed food allergy, suggesting a dose-response relationship (each dog owned aOR 0.12 (CI 0.02-0.81), P = 0.03). No relationship was demonstrated between owning dogs or cats and the development of AD.

CONCLUSION

Dog ownership in infancy may prevent food allergy.

Vitamin D status in preschool children and its relations to vitamin D sources and body mass index-Fish Intervention Studies-KIDS (FINS-KIDS)

OBJECTIVES

The aims of this study were to determine vitamin D status (serum 25-hydroxyvitamin D₃ [s-25(OH)D₃]) and examine possible associations between vitamin D status and vitamin D-rich dietary sources, sun exposure, and body mass index in preschool children ages 4 to 6 y.

METHODS

This is a cross-sectional study based on baseline data (collected in January-February 2015) from the two-armed randomized controlled trial Fish Intervention Studies-KIDS (FINS-KIDS) conducted in Bergen, Norway. S-25(OH)D₃ concentration was determined by liquid chromatography-tandem mass spectrometry. Information regarding habitual dietary intake, recent sun vacations, and body mass index were assessed with questionnaires answered by the children's caregivers.

RESULTS

The children (n = 212) had a mean (standard deviation) s-25(OH)D₃ of 60.7 (13.8) nmol/L; 18.9% had s-25(OH)D₃ ≤50 nmol/L. In logistic regression models, non-overweight versus overweight status was inversely associated with s-25(OH)D₃ ≤50 nmol/L (odds ratio: 0.41; 95% confidence interval, 0.18-0.95; P = 0.037). Non-sun versus sun vacations were associated with s-25(OH)D₃ ≤75 nmol/L (odds ratio: 5.33; 95% confidence interval, 1.93-14.77; P = 0.001).

CONCLUSIONS

The majority of the preschool children (81%) had s-25(OH)D₃ >50 nmol/L. Children with overweight status had an increased risk of s-25(OH)D₃ ≤50 nmol/L, and children who had not been on sun vacations were at a greater risk of s-25(OH)D₃ ≤75 nmol/L.

Age at introduction to complementary solid food and food allergy and sensitization: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

An infant's age at introduction of complementary solids may contribute to food allergy. We aimed to synthesize the literature on the association between age at introduction of complementary solids, excluding milk products, and food allergy and sensitization.

DESIGN

We searched the electronic databases PubMed and EMBASE (January 1946-February 2017) using solid food, allergy and sensitization terms.

METHODS

Two authors selected papers according to inclusion criteria, identifying 16 cohort studies, 1 case-control study and 8 randomized controlled trials (RCTs). Pooled effects across studies were estimated using random-effects meta-analysis.

RESULTS

Cohort studies-Introducing complementary solids at age ≥ 4 months vs <4 months was not associated with food allergy (OR 1.22; 95% CI, 0.76-1.96) but was associated with food sensitization (OR 1.93; 95% CI 1.57-2.38). First exposure from age 4 to 6 months vs <4 months was not associated with food allergy (OR 1.01; 95% CI, 0.64-1.60) but was associated with food sensitization (OR 2.46; 95% CI 1.55-3.86). Randomized controlled trials-Egg exposure from age 4 months was associated with reduced egg allergy (OR 0.63, 95% CI, 0.44-0.90) and sensitization (OR 0.76, 95% CI, 0.51-0.95). Peanut exposure from age 4 months compared to delayed exposure was associated with reduced peanut allergy (OR 0.28, 95% CI 0.14-0.57).

CONCLUSIONS

We found no evidence from observational studies that introducing solids before 4 months protected against food allergy, but there was evidence for protection against food sensitization. From RCTs, introducing egg from 4 to 6 months and peanut from 4 to 11 months reduced the risk of egg allergy, peanut allergy and egg sensitization. PROSPERO systematic review registry (CRD42016033473).

Pediatric Eosinophilic Esophagitis: Results of the European Retrospective Pediatric Eosinophilic Esophagitis Registry (RetroPEER)

OBJECTIVES

Recommendations for diagnosing and treating eosinophilic esophagitis (EoE) are evolving; however, information on real world clinical practice is lacking. To assess the practices of pediatric gastroenterologists diagnosing and treating EoE and to identify the triggering allergens in European children.

METHODS

Retrospective anonymized data were collected from 26 European pediatric gastroenterology centers in 13 countries. Inclusion criteria were: Patients diagnosis with EoE, completed investigations prescribed by the treating physician, and were on stable medical or dietary interventions.

RESULTS

In total, 410 patients diagnosed between December 1999 and June 2016 were analyzed, 76.3% boys. The time from symptoms to diagnosis was 12 ± 33.5 months and age at diagnosis was 8.9 ± 4.75 years. The most frequent indications for endoscopy were: dysphagia (38%), gastroesophageal reflux (31.2%), bolus impaction (24.4%), and failure to thrive (10.5%). Approximately 70.3% had failed proton pump inhibitor treatment. The foods found to be causative of EoE by elimination and rechallenge were milk (42%), egg (21.5%), wheat/gluten (10.9%), and peanut (9.9%). Elimination diets were used exclusively in 154 of 410 (37.5%), topical steroids without elimination diets in 52 of 410 (12.6%), both diet and steroids in 183 of 410 (44.6%), systemic steroids in 22 of 410 (5.3%), and esophageal dilation in 7 of 410 (1.7%). Patient refusal, shortage of endoscopy time, and reluctance to perform multiple endoscopies per patient were noted as factors justifying deviation from guidelines.

CONCLUSIONS

In this "real world" pediatric European cohort, milk and egg were the most common allergens triggering EoE. Although high-dose proton pump inhibitor trials have increased, attempted PPI treatment is not universal.

Non-IgE-mediated gastrointestinal allergies-Do they have a place in a new model of the Allergic March

The rise in food allergy has been described as the "second wave" of the allergy epidemic, with some developed countries reporting a prevalence of 10% of challenge-proven food allergies. Recognition of the Allergic March has played a crucial role in identifying causality in allergic conditions, linking atopic dermatitis to food allergy and food allergy to other atopic disorders, thereby highlighting opportunities in prevention and the importance of early intervention. This publication will establish the value of weaving the less well-understood, non-IgE-mediated food allergy into the Allergic March and mapping its progression through childhood and its associated co-morbidities. The proposed non-IgE-mediated Allergic March highlights the concomitant presentation of gastrointestinal symptoms and atopic dermatitis as early presenting symptoms in confirmed non-IgE-mediated allergies and the later development of atopic co-morbidities, including asthma and allergic rhinitis, similar to the IgE-mediated Allergic March. This publication highlights recent observations of a link between non-IgE-mediated food allergy in early childhood and functional gastrointestinal disorders in later life and also the reported occurrence of extra-intestinal manifestations at later ages. Although significant limitations exist in regard to the proposed evolution of the Allergic March model, the authors hope that this publication will influence the management of non-IgE-mediated gastrointestinal allergies and inform future research and interventions.

Gut Microbiome as Target for Innovative Strategies Against Food Allergy

The dramatic increase in food allergy prevalence and severity globally requires effective strategies. Food allergy derives from a defect in immune tolerance mechanisms. Immune tolerance is modulated by gut microbiota function and structure, and microbiome alterations (dysbiosis) have a pivotal role in the development of food allergy. Environmental factors, including a low-fiber/high-fat diet, cesarean delivery, antiseptic agents, lack of breastfeeding, and drugs can induce gut microbiome dysbiosis, and have been associated with food allergy. New experimental tools and technologies have provided information regarding the role of metabolites generated from dietary nutrients and selected probiotic strains that could act on immune tolerance mechanisms. The mechanisms are multiple and still not completely defined. Increasing evidence has provided useful information on optimal bacterial species/strains, dosage, and timing for intervention. The increased knowledge of the crucial role played by nutrients and gut microbiota-derived metabolites is opening the way to a post-biotic approach in the stimulation of immune tolerance through epigenetic regulation. This review focused on the potential role of gut microbiome as the target for innovative strategies against food allergy.

Current Trends in Tolerance Induction in Cow's Milk Allergy: From Passive to Proactive Strategies

This review addresses the current strategies of inducing tolerance development in infant and childhood cow's milk protein allergy (CMPA). The change in prevention strategies for CMPA has been emphasized based on the lack of evidence to support the efficacy of food allergen avoidance in infancy and the concept of the dual-allergen-exposure hypothesis, which suggests that allergen exposure through the skin leads to sensitization, whereas early oral consumption of allergenic food protein induces oral tolerance. The new approach is based on the likelihood of early introduction of allergenic foods to the infant's diet to reduce the development of food allergies through oral tolerance induction. The latest treatment guidelines recommend the continuation of breast feeding and the elimination of cow's milk and products from the maternal diet in exclusively breast-fed infants with CMPA, the use of an extensively hydrolyzed infant formula (eHF) with proven efficacy in CMPA as the first elimination diet in formula-fed infants with CMPA and the use of amino acid-based formula (AAF) in severe cases, such as anaphylaxis, enteropathy, eosinophilic esophagitis, and food protein-induced enterocolitis syndrome (FPIES), as well as cases of multiple system involvement, multiple food allergies, and intolerance to extensively hydrolyzed formula (eHF). In conclusion, this paper presents the current knowledge on tolerance development in infants and children with CMPA to increase the awareness of the clinicians concerning the new approaches in CMPA treatment Tolerance development is considered a relatively new concept in CMPA, inducing a shift in interventions in CMPA from a passive (avoidance of responsible allergen) toward a proactive (tolerance induction) strategy.

Food Allergy Prevalence in Salvadoran Schoolchildren Estimated by Parent-Report

The prevalence of food allergy (FA) has not been estimated at a population level in Central American countries and, consequently, the magnitude and relevance of the problem in the Central American region remains unknown. Thus, our aim was to evaluate the parent-reported prevalence of FA in a population of schoolchildren from the Central American country El Salvador. A Spanish version of a structured questionnaire was utilized. Five hundred and eight (508) parents returned the questionnaire with valid responses (response rate, 32%). The estimated prevalence rates (95% CI) were: adverse food reactions 15.9 (13.0–19.3), “perceived FA, ever” 11.6 (9.1–14.6), “physician-diagnosed FA, ever” 5.7% (4.0–8.0), “immediate-type FA, ever” 8.8% (6.6–11.6), “immediate-type FA, current” 5.3% (3.6–7.6), and anaphylaxis 2.5% (1.5–4.3). The most common food allergens were milk (1.7%), shrimp (1.3), chili (0.7%), chocolate (0.7%), and nuts (0.3%). Most of the “food-dependent anaphylaxis” cases (60.5%) sought medical attention, but only one case reported the prescription of an epinephrine autoinjector. Mild and severe FA cases are not uncommon among Salvadoran schoolchildren and both the prescription of epinephrine autoinjectors by healthcare personnel and the use of the autoinjectors by anaphylactic individuals should be encouraged.

Nutritional disorders resulting from food allergy in children

The elimination of food allergens that contribute essential nutrients in paediatrics may lead to the development of nutritional disorders. The most common nutritional disorders include poor growth, micronutrient deficiencies and feeding difficulties. Of the aforementioned, growth faltering has been well studied and is seen as a common presenting factor in paediatric food allergy. However, the use of different criteria and cut-off values makes it difficult to establish the overall effect. The impact of number and type of foods eliminated and comorbidities has yielded varying results, although there seems to be a trend towards worsening growth with atopic dermatitis and the avoidance of cow's milk. Low micronutrient intake is common in paediatric food allergy; however, a low intake does not necessarily translate into a deficiency as measured by biomarkers. Vitamin D and calcium have been well studied, and a long-lasting impact on bone mineral density has been found. However, other micronutrient deficiencies have also been found and should also be considered. Feeding difficulties is a common complaint in clinical practice, but limited data have been published in food allergy. Poor growth and reflux/vomiting have been shown to be associated with feeding difficulties, in particular in non-IgE-mediated food allergies. There seems to be a long-lasting effect on feeding, in particular in cow's milk allergy, which needs to be taken into account with dietary input. The interplay between growth, feeding difficulties and micronutrient deficiencies has been implied in some studies, but cause and effect is not well established and requires further research.

Higher Polygenetic Predisposition for Asthma in Cow's Milk Allergic Children

Cow’s milk allergy (CMA) is an early-onset allergy of which the underlying genetic factors remain largely undiscovered. CMA has been found to co-occur with other allergies and immunological hypersensitivity disorders, suggesting a shared genetic etiology. We aimed to (1) investigate and (2) validate whether CMA children carry a higher genetic susceptibility for other immunological hypersensitivity disorders using polygenic risk score analysis (PRS) and prospective phenotypic data. Twenty-two CMA patients of the Dutch EuroPrevall birth cohort study and 307 reference subjects were genotyped using single nucleotide polymorphism (SNP) array. Differentially genetic susceptibility was estimated using PRS, based on multiple P-value thresholds for SNP inclusion of previously reported genome-wide association studies (GWAS) on asthma, autism spectrum disorder, atopic dermatitis, inflammatory bowel disease and rheumatoid arthritis. These associations were validated with prospective data outcomes during a six-year follow-up in 19 patients. We observed robust and significantly higher PRSs of asthma in CMA children compared to the reference set. Association analyses using the prospective data indicated significant higher PRSs in former CMA patients suffering from asthma and related traits. Our results suggest a shared genetic etiology between CMA and asthma and a considerable predictive sensitivity potential for subsequent onset of asthma which indicates a potential use for early clinical asthma intervention programs.

The Epidemiology of Food Allergy in the Global Context

There is a lack of high-quality evidence based on the gold standard of oral food challenges to determine food allergy prevalence. Nevertheless, studies using surrogate measures of food allergy, such as health service utilization and clinical history, together with allergen-specific immunoglobulin E (sIgE), provide compelling data that the prevalence of food allergy is increasing in both Western and developing countries. In Western countries, challenge-diagnosed food allergy has been reported to be as high as 10%, with the greatest prevalence noted among younger children. There is also growing evidence of increasing prevalence in developing countries, with rates of challenge-diagnosed food allergy in China and Africa reported to be similar to that in Western countries. An interesting observation is that children of East Asian or African descent born in a Western environment are at higher risk of food allergy compared to Caucasian children; this intriguing finding emphasizes the importance of genome-environment interactions and forecasts future increases in food allergy in Asia and Africa as economic growth continues in these regions. While cow’s milk and egg allergy are two of the most common food allergies in most countries, diverse patterns of food allergy can be observed in individual geographic regions determined by each country’s feeding patterns. More robust studies investigating food allergy prevalence, particularly in Asia and the developing world, are necessary to understand the extent of the food allergy problem and identify preventive strategies to cope with the potential increase in these regions.

Characterization and Detection of Food Allergens Using High-Resolution Mass Spectrometry: Current Status and Future Perspective

Allergic reactions to food are among the major food safety concerns in industrialized countries, and it is estimated that approximately 5% of the population suffers from immunoglobulin-E-mediated food allergy. High-resolution mass spectrometry has become one of the most important techniques for the molecular characterization of allergens, including structural modification, degradation in the gastrointestinal environment, or identification of suitable marker peptides for the development of novel analytical approaches, in the past decade. This perspective aims to briefly summarize the current situation and discuss future developments.

How does dose impact on the severity of food-induced allergic reactions, and can this improve risk assessment for allergenic foods?: Report from an ILSI Europe Food Allergy Task Force Expert Group and Workshop

Quantitative risk assessment (QRA) for food allergens has made considerable progress in recent years, yet acceptability of its outcomes remains stymied because of the limited extent to which it has been possible to incorporate severity as a variable. Reaction severity, particularly following accidental exposure, depends on multiple factors, related to the allergen, the host and any treatments, which might be administered. Some of these factors are plausibly still unknown. Quantitative risk assessment shows that limiting exposure through control of dose reduces the rates of reactions in allergic populations, but its impact on the relative frequency of severe reactions at different doses is unclear. Food challenge studies suggest that the relationship between dose of allergenic food and reaction severity is complex even under relatively controlled conditions. Because of these complexities, epidemiological studies provide very limited insight into this aspect of the dose-response relationship. Emerging data from single-dose challenges suggest that graded food challenges may overestimate the rate of severe reactions. It may be necessary to generate new data (such as those from single-dose challenges) to reliably identify the effect of dose on severity for use in QRA. Success will reduce uncertainty in the susceptible population and improve consumer choice.

Consensus document on dog and cat allergy

The prevalence of sensitization to dogs and cats varies by country, exposure time and predisposition to atopy. It is estimated that 26% of European adults coming to the clinic for suspected allergy to inhalant allergens are sensitized to cats and 27% to dogs. This document is intended to be a useful tool for clinicians involved in the management of people with dog or cat allergy. It was prepared from a consensus process based on the RAND/UCLA method. Following a literature review, it proposes various recommendations concerning the diagnosis and treatment of these patients, grounded in evidence and clinical experience. The diagnosis of dog and cat allergy is based on a medical history and physical examination that are consistent with each other and is confirmed with positive results on specific IgE skin tests. Sometimes, especially in polysensitized patients, molecular diagnosis is strongly recommended. Although the most advisable measure would be to avoid the animal, this is often impossible and associated with a major emotional impact. Furthermore, indirect exposure to allergens occurs in environments in which animals are not present. Immunotherapy is emerging as a potential solution to this problem, although further supporting studies are needed.

Fish oil in infancy protects against food allergy in Iceland-Results from a birth cohort study

BACKGROUND

Consumption of oily fish or fish oil during pregnancy, lactation and infancy has been linked to a reduction in the development of allergic diseases in childhood.

METHODS

In an observational study, Icelandic children (n = 1304) were prospectively followed from birth to 2.5 years with detailed questionnaires administered at birth and at 1 and 2 years of age, including questions about fish oil supplementation. Children with suspected food allergy were invited for physical examinations, allergic sensitization tests, and a double-blind, placebo-controlled food challenge if the allergy testing or clinical history indicated food allergy. The study investigated the development of sensitization to food and confirmed food allergy according to age and frequency of postnatal fish oil supplementation using proportional hazards modelling.

RESULTS

The incidence of diagnosed food sensitization was significantly lower in children who received regular fish oil supplementation (relative risk: 0.51, 95% confidence interval: 0.32-0.82). The incidence of challenge-confirmed food allergy was also reduced, although not statistically significant (0.57, 0.30-1.12). Children who began to receive fish oil in their first half year of life were significantly more protected than those who began later (P = .045 for sensitization, P = .018 for allergy). Indicators of allergy severity decreased with increased fish oil consumption (P = .013). Adjusting for parent education and allergic family history did not change the results.

CONCLUSION

Postnatal fish oil consumption is associated with decreased food sensitization and food allergies in infants and may provide an intervention strategy for allergy prevention.

Prevalence estimates and risk factors for early childhood wheeze across Europe: the EuroPrevall birth cohort

BACKGROUND

Preschool wheeze is an important problem worldwide. No comparative population-based studies covering different countries have previously been undertaken.

OBJECTIVE

To assess the prevalence of early childhood wheeze across Europe and evaluate risk factors focusing on food allergy, breast feeding and smoke exposure.

METHODS

Infants from nine countries were recruited into the EuroPrevall birth cohort. At 12 and 24 months, data on wheeze, allergic signs/symptoms, feeding, smoke exposure, infections and day care attendance were collected using questionnaires. Poisson regression was used to assess risk factors for wheeze.

RESULTS

12 049 infants were recruited. Data from the second year of life were available in 8805 (73.1%). The prevalence of wheeze in the second year of life ranged from <2% in Lodz (Poland) and Vilnius (Lithuania) to 13.1% (95% CI 10.7% to 15.5%) in Southampton (UK) and 17.2% (95% CI 15.0% 19.5%) in Reykjavik (Iceland). In multivariable analysis, frequent lower respiratory tract infections in the first and second years of life (incidence rate ratio (IRR) 1.9 (95% CI 1.3 to 2.6) and 2.5 (95% CI 1.9 to3.4), respectively), postnatal maternal smoking (IRR 1.6, 95% CI 1.1 to 2.4), day care attendance (IRR 1.6, 95% CI 1.1 to 2.5) and male gender (IRR 1.3, 95% CI 1.0 to 1.7) were associated with wheeze. The strength of their association with wheeze differed between countries. Food allergy and breast feeding were not independently associated with wheeze.

CONCLUSION

The prevalence of early childhood wheeze varied considerably across Europe. Lower respiratory tract infections, day care attendance, postnatal smoke exposure and male gender are important risk factors. Further research is needed to identify additional modifiable risk factors that may differ between countries.

The nutrition-gut microbiome-physiology axis and allergic diseases

Dietary and bacterial metabolites influence immune responses. This raises the question whether the increased incidence of allergies, asthma, some autoimmune diseases, cardiovascular disease, and others might relate to intake of unhealthy foods, and the decreased intake of dietary fiber. In recent years, new knowledge on the molecular mechanisms underpinning a 'diet-gut microbiota-physiology axis' has emerged to substantiate this idea. Fiber is fermented to short chain fatty acids (SCFAs), particularly acetate, butyrate, and propionate. These metabolites bind 'metabolite-sensing' G-protein-coupled receptors such as GPR43, GPR41, and GPR109A. These receptors play fundamental roles in the promotion of gut homeostasis and the regulation of inflammatory responses. For instance, these receptors and their metabolites influence Treg biology, epithelial integrity, gut homeostasis, DC biology, and IgA antibody responses. The SCFAs also influence gene transcription in many cells and tissues, through their inhibition of histone deacetylase expression or function. Contained in this mix is the gut microbiome, as commensal bacteria in the gut have the necessary enzymes to digest dietary fiber to SCFAs, and dysbiosis in the gut may affect the production of SCFAs and their distribution to tissues throughout the body. SCFAs can epigenetically modify DNA, and so may be one mechanism to account for diseases with a 'developmental origin', whereby in utero or post-natal exposure to environmental factors (such as nutrition of the mother) may account for disease later in life. If the nutrition-gut microbiome-physiology axis does underpin at least some of the Western lifestyle influence on asthma and allergies, then there is tremendous scope to correct this with healthy foodstuffs, probiotics, and prebiotics.

Physician's appraisal vs documented signs and symptoms in the interpretation of food challenge tests: The EuroPrevall birth cohort

BACKGROUND

Blinded food challenges are considered the current gold standard for the diagnosis of food allergies. We used data from a pan-European multicenter project to assess differences between study centers, aiming to identify the impact of subjective aspects for the interpretation of oral food challenges.

METHODS

Nine study centers of the EuroPrevall birth cohort study about food allergy recruited 12 049 newborns and followed them for up to 30 months in regular intervals. Intensive training was conducted and every center visited to ensure similar handling of the protocols. Suspected food allergy was clinically evaluated by double-blind, placebo-controlled food challenges using a nine dose escalation protocol. The primary challenge outcomes based on physician's appraisal were compared to documented signs and symptoms.

RESULTS

Of 839 challenges conducted, study centers confirmed food allergy in 15.6% to 53.6% of locally conducted challenges. Centers reported 0 to 16 positive placebo challenges. Worsening of eczema was the most common sign when challenged with placebo. Agreement between documented objective signs and the challenge outcome assigned by the physician was heterogeneous, with Cohen's kappa spanning from 0.42 to 0.84.

CONCLUSIONS

These differences suggest that the comparison of food challenge outcomes between centers is difficult despite common protocols and training. We recommend detailed symptom assessment and documentation as well as objective sign-based challenge outcome algorithms to assure accuracy and comparability of blinded food challenges. Training and supervision of staff conducting food challenges is a mandatory component of reliable outcome data.

The effect of early feeding practices on growth indices and obesity at preschool children from four European countries and UK schoolchildren and adolescents

Not only healthy growth but also childhood obesity partly originate from early life. The current work aimed to examine the association of feeding practices during infancy with growth and adiposity indices in preschool children from four European countries and in UK schoolchildren and adolescents. Existing data from four European birth cohorts (ALSPAC-UK, EDEN-France, EuroPrevall-Greece and Generation XXI-Portugal) were used. Anthropometrics and body composition indices were collected. Parallel multivariate regression analyses were performed to examine the research hypothesis. Overall, the analyses showed that breastfeeding and timing of complementary feeding were not consistently associated with height z-score, overweight/obesity, and body fat mass in children or adolescents. However, breastfeeding duration for less than 6 months was associated with lower height z-scores in 5-year-old French children (P < 0.001) but with higher height z-scores in 4-year-old UK children (P = 0.006). Furthermore, introduction of complementary foods earlier than 4 months of age was positively associated with fat mass levels in 5-year-old French children (P = 0.026).

CONCLUSION

Early feeding practices, i.e., any breastfeeding duration and age of introduction of complementary foods, do not appear to be consistently associated with height z-score, overweight/obesity, and body fat mass in preschool children from four European countries and in UK schoolchildren and adolescents. What is known? • Healthy growth and childhood obesity partly originate from early life. What is new? • Breastfeeding duration less than 6 months was associated with lower height z-scores in 5-year-old French children, while the opposite was observed in 4-year-old British children. • Introduction of complementary foods earlier than 4 months was positively associated with fat mass levels in 5-year-old French children, but not in the other three countries. • Early feeding practices did not appear to be consistently associated with growth and adiposity indices, and as such, no clear influence can be observed.

Allergic profiles of mothers and fathers in the Japan Environment and Children's Study (JECS): a nationwide birth cohort study

BACKGROUND

The Japan Environment and Children's Study (JECS) is a nationwide, multicenter, prospective birth cohort investigation launched by the Ministry of Environment in Japan. The purpose of the JECS is to evaluate the influence of prenatal and postnatal exposures to environmental factors on the postnatal health of the children. In this study, we evaluated the allergic characteristics of parents within the JECS cohort.

METHODS

This study covered a wide geographical area and encompassed 15 regional centers. We obtained information regarding doctor diagnosed allergic diseases by using maternal and/or paternal self-administered questionnaires during the first trimester of pregnancy. Blood samples were also obtained from mothers and/or fathers to detect serum IgE concentrations.

RESULTS

The prevalences of asthma, allergic rhinitis (hay fever), atopic dermatitis, and food allergy were 10.9, 36.0, 15.7 and 4.8%, respectively, among 99,013 mothers; these prevalences among 49,991 fathers were 10.8, 30.3, 11.2 and 3.3%, respectively. Any positive antigen-specific IgE sensitization was found in 73.9% of mothers. The most abundant antigen sensitization in mothers was to Japanese cedar (55.6%), followed by Der p 1 (48%); only 1.0% of mothers were sensitized to egg white.

CONCLUSIONS

This is the first epidemiological report on allergic disorders and allergen sensitization of parents during pregnancy among the Japanese general population.

Amino Acid-based Formula in Cow's Milk Allergy: Long-term Effects on Body Growth and Protein Metabolism

OBJECTIVES

The long-term effects of amino acid-based formula (AAF) in the treatment of cow's milk allergy (CMA) are largely unexplored. The present study comparatively evaluates body growth and protein metabolism in CMA children treated with AAF or with extensively hydrolyzed whey formula (eHWF), and healthy controls.

METHODS

A 12-month multicenter randomized control trial was conducted in outpatients with CMA (age 5-12 m) randomized in 2 groups, treated with AAF (group 1) and eHWF (group 2), and compared with healthy controls (group 3) fed with follow-on (if age <12 months) or growing-up formula (if age >12 months). At enrolment (T0), after 3 (T3), 6 (T6), and 12 months (T12) a clinical evaluation was performed. At T0 and T3, in subjects with CMA serum levels of albumin, urea, total protein, retinol-binding protein, and insulin-like growth factor 1 were measured.

RESULTS

Twenty-one subjects in group 1 (61.9% boys, age 6.5 ± 1.5 months), 19 in group 2 (57.9% boys, age 7 ± 1.7 months) and 25 subjects in group 3 (48% boys, age 5.5 ± 0.5 months) completed the study. At T0, the weight z score was similar in group 1 (-0.74) and 2 (-0.76), with differences compared to group 3 (-0.17, P < 0.05). At T12, the weight z score value was similar between the 3 groups without significant differences. There were no significant changes in protein metabolism in children in groups 1 and 2.

CONCLUSION

Long-term treatment with AAF is safe and allows adequate body growth in children with CMA.

A new framework for the documentation and interpretation of oral food challenges in population-based and clinical research

BACKGROUND

The conduct of oral food challenges as the preferred diagnostic standard for food allergy (FA) was harmonized over the last years. However, documentation and interpretation of challenge results, particularly in research settings, are not sufficiently standardized to allow valid comparisons between studies. Our aim was to develop a diagnostic toolbox to capture and report clinical observations in double-blind placebo-controlled food challenges (DBPCFC).

METHODS

A group of experienced allergists, paediatricians, dieticians, epidemiologists and data managers developed generic case report forms and standard operating procedures for DBPCFCs and piloted them in three clinical centres. The follow-up of the EuroPrevall/iFAAM birth cohort and other iFAAM work packages applied these methods.

RECOMMENDATIONS

A set of newly developed questionnaire or interview items capture the history of FA. Together with sensitization status, this forms the basis for the decision to perform a DBPCFC, following a standardized decision algorithm. A generic form including details about severity and timing captures signs and symptoms observed during or after the procedures. In contrast to the commonly used dichotomous outcome FA vs no FA, the allergy status is interpreted in multiple categories to reflect the complexity of clinical decision-making.

CONCLUSION

The proposed toolbox sets a standard for improved documentation and harmonized interpretation of DBPCFCs. By a detailed documentation and common terminology for communicating outcomes, these tools hope to reduce the influence of subjective judgment of supervising physicians. All forms are publicly available for further evolution and free use in clinical and research settings.