Randomized controlled trial of early regular egg intake to prevent egg allergy

Introduction of allergenic food to infants and allergic and autoimmune conditions: a systematic review and meta-analysis

OBJECTIVES

To evaluate the effects of early introduction to allergenic foods compared with late introduction and its impact on food allergy, food sensitisation and autoimmune disease risk.

DESIGN AND SETTING

The systematic review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Four electronic databases (MEDLINE, CENTRAL, EMBASE and CINAHL) were searched from inception till 24 October 2022 using keywords and MeSH without limitations on publication's language or date. A forward and backwards citation analysis was also conducted. Risk of bias was assessed by three authors independently, in pairs using the Cochrane Risk of Bias Tool 2. Findings were narratively and quantitatively synthesised. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach.

PARTICIPANTS

Randomised controlled trials (RCTs) on allergenic food introduction prior to 12 months of age that evaluated its effect on the development of allergic and autoimmune conditions.

INTERVENTION

Early introduction to allergenic foods to infants diet.

MAIN OUTCOME MEASURES

(1) Food allergy and sensitisation with main measures including oral food challenge, specific-IgE, skin prick testing, physician assessment and parental reporting. (2) Allergic and autoimmune conditions such as asthma and eczema.

RESULTS

Of the 9060 identified records, we included 12 RCTs. We found high to moderate certainty evidence suggested that early introduction of allergen-containing foods reduces the risk of multiple food allergies (4 RCTs, 3854 participants, RR 0.49, 95% CI 0.33 to 0.74), egg (8 RCTs, 5193 participants, RR 0.58, 95% CI 0.44 to 0.78), peanut (3 RCTs, 4183 participants, RR 0.31, 95% CI 0.17 to 0.54) and atopic dermatitis or eczema (4 RCTs, 3579 participants, RR 0.88, 95% CI 0.78 to 1.00). Effects on other food allergies including milk, wheat, fish; autoimmune conditions, and food sensitisation are very uncertain and informed by low and very-low certainty evidence. No important subgroup differences were observed related to baseline risk of allergy and age at introduction. Sensitivity analyses limited to low risk of bias RCTs showed similar results.

CONCLUSIONS

This systematic review and meta-analysis shows that early introduction of allergen-containing food from 4 to 12 months of age, was associated with lower risk of multiple food allergy and eczema. Further research on other allergenic foods, and their long-term impact on food allergy and autoimmune risk is essential for enhancing our understanding on development of these conditions and guiding future clinical recommendations.

PROSPERO REGISTRATION NUMBER

CRD42022375679.

Complementary Feeding: Tradition, Innovation and Pitfalls

According to WHO, "complementary feeding (CF) is the process starting when breast milk alone or infant formula alone is no longer sufficient to meet the nutritional requirements of infants, and therefore, other foods and liquids are needed, along with breast human milk or a breastmilk substitute". CF is one of the most important "critical and sensitive periods" in human life: indeed, timing and approaches to solid foods introduction in an infant's nutrition are of utmost importance as potential epigenetic factors from infancy to adulthood. CF is also deeply influenced by each country and single-family traditions, culture, and beliefs. The aim of our narrative review is to analyze traditional CF practices, including innovative and alternative ones that emerged in the last decades, such as baby-led weaning or plant-based weaning, and to evaluate their effects on the risk of developing non-communicable diseases. Moreover, we will discuss pitfalls and misunderstandings that pediatricians frequently have to face when dealing with complementary feeding. Health care professionals must not have prejudices against parents' wishes or traditions about CF; rather, they should support and educate them in case of any alternative CF choice, always pursuing the infant's adequate growth, neuro- and taste development, and the achievement of correct eating behavior as the primary goal.

Dietary Intervention during Weaning and Development of Food Allergy: What Is the State of the Art?

Food allergy (FA) affects approximately 6-8% of children worldwide causing a significant impact on the quality of life of children and their families. In past years, the possible role of weaning in the development of FA has been studied. According to recent studies, this is still controversial and influenced by several factors, such as the type of food, the age at food introduction and family history. In this narrative review, we aimed to collect the most recent evidence about weaning and its role in FA development, organizing the gathered data based on both the type of study and the food. As shown in most of the studies included in this review, early food introduction did not show a potential protective role against FA development, and we conclude that further evidence is needed from future clinical trials.

Anaphylaxis: A 2023 practice parameter update

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

Complementary Feeding Practices: Recommendations of Pediatricians for Infants with and without Allergy Risk

AIM

To investigate the routine guidance provided by pediatricians concerning the timing of complementary feeding (CF) for both healthy infants and those at a heightened risk of allergies.

METHODS

A total of 233 pediatricians participated in an anonymous online survey that included questions about demographics and recommendations for CF. Specifically, they provided guidance on the types of foods, preparation methods, supplements, time intervals for introducing new foods to infants at low and high allergy risk, and delayed food introductions for high-risk cases.

RESULTS

The respondents advised introducing certain foods at specific ages: fruits, starchy non-gluten grains, vegetables, olive oil, and meat were appropriate at 6 months; gluten-rich grains at 7 months; yogurt, hard-boiled eggs, and legumes at 8 months; fish at 8.5 months; and nuts at 9 months. Pediatricians, especially those with less than 15 years of practice, often introduced egg, seafood, gluten-rich grains, legumes, and nuts earlier for high-risk infants. Parenthood and male gender were associated with the earlier introduction of eggs and grains.

CONCLUSIONS

Greek pediatricians follow a structured food introduction schedule for CF in infants. Interestingly, they tend to delay the introduction of common food allergens and recommend longer intervals between introducing new foods, particularly for high-risk infants. Key Notes: Despite recent evidence-based indications on healthy complementary feeding strategies for infants, discrepancies persist among pediatricians regarding food choices and the order and timing of food introduction, both for healthy infants and those at risk of allergy. Guidance on complementary feeding by pediatricians is influenced by their individual characteristics. Pediatricians tend to delay the introduction of common food allergens and recommend longer intervals between introducing new foods, particularly for high-risk infants.

Egg-sensitised infants have elevated CD4+ effector memory T regulatory cells from birth

BACKGROUND

IgE-mediated sensitisation to egg is common in infants. In some cases, the processes leading to egg sensitisation are established in early life, even before introduction to solid foods. The underlying mechanisms remain poorly understood.

METHODS

We performed detailed immune cell phenotyping of peripheral blood mononuclear cells and determined in vitro cytokine responses following allergen specific and non-specific immune stimulation. To determine if unique immune profiles were linked to early-life egg sensitisation, we compared 92 infants at 4-6 months of age, with (EggCAP+, n = 41) and without (EggCAP-, n = 51) early egg sensitisation. Additionally, 47 cord blood samples were analysed. For a subset of participants (n = 39), matching cord blood mononuclear cells were assessed by flow cytometry to establish the impact of IgE sensitisation on immune developmental trajectories.

RESULTS

EggCAP+ infants were found to exhibit a unique immune phenotype characterised by increased levels of circulating CD4+ T regulatory cells (Treg), CD4+ effector memory (EM) Treg and increased expression of the IgE receptor, FcεR1, on basophils. The increased CD4+ EM Treg profiles were already present in cord blood samples from EggCAP+ infants. A general Th2-skewing of the immune system was observed based on increased IL-13 production following phytohemagglutinin stimulation and by comparing immune developmental trajectories, EggCAP+ infants displayed an expansion of basophils and reduced levels of CD4- T cells compared to EggCAP- infants.

CONCLUSIONS

Immunological profiles associated with egg sensitisation are detectable in infant circulation at 4-6 months of age and at birth. Understanding the immune mechanisms underlying early-life sensitisation could provide important insights for future food allergy prevention strategies.

Effects of Early Diet on the Prevalence of Allergic Disease in Children: A Systematic Review and Meta-Analysis

Recent evidence suggests that the timing of introduction, types, and amounts of complementary foods/allergenic foods may influence the risk of allergic disease. However, the evidence has not been updated and comprehensively synthesized. The Cochrane Library, EMBASE, Web of Science, and PubMed databases were searched from the inception of each database up to 31 May 2023 (articles prior to 2000 were excluded manually). Statistical analyses were performed using RevMan 5. The GRADE approach was followed to rate the certainty of evidence. Compared with >6 mo, early introduction of eggs (≤6 mo of age) might reduce the risk of food allergies in preschoolers aged <6 y (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.53, 0.81), but had no effect on asthma or atopic dermatitis (AD). Consumption of fish at 6-12 mo might reduce the risk of asthma in children (aged 5-17 y) compared with late introduction after 12 mo (OR, 0.61; 95% CI: 0.52, 0.72). Introduction of allergenic foods for ≤6 mo of age, compared with >6 mos, was a protective factor for the future risk (children aged ≤10 y) of AD (OR, 0.93; 95% CI: 0.89, 0.97). Probiotic intervention for infants at high risk of allergic disease significantly reduced the risk of food allergy at ages 0-3 y (OR, 0.72; 95% CI: 0.56, 0.94), asthma at 6-12 y (OR, 0.61; 95% CI: 0.41, 0.90), and AD at aged <6 y (3-6 y: OR, 0.70; 95% CI: 0.52, 0.94; 0-3 y: OR, 0.73; 95% CI: 0.59, 0.91). Early introduction of complementary foods or the high-dose vitamin D supplementation in infancy was not associated with the risk of developing food allergies, asthma, or AD during childhood. Early introduction to potential allergen foods for normal infants or probiotics for infants at high risk of allergies may protect against development of allergic disease. This study was registered at PROSPERO as CRD42022379264.

Tolerance to heated egg in egg allergy: Explanations and implications for prevention and treatment

Hen's egg allergy is the second most frequent food allergy found in children. Allergic symptoms can be caused by raw or heated egg, but a majority of egg-allergic children can tolerate hard-boiled or baked egg. Understanding the reasons for the tolerance towards heated egg provides clues about the molecular mechanisms involved in egg allergy, and the differential allergenicity of heated and baked egg might be exploited to prevent or treat egg allergy. In this review, we therefore discuss (i) why some patients are able to tolerate heated egg; by highlighting the structural changes of egg white (EW) proteins upon heating and their impact on immunoreactivity, as well as patient characteristics, and (ii) to what extent heated or baked EW might be useful for primary prevention strategies or oral immunotherapy. We describe that the level of immunoreactivity towards EW helps to discriminate patients tolerant or reactive to heated or baked egg. Furthermore, the use of heated or baked egg seems effective in primary prevention strategies and might limit adverse reactions. Oral immunotherapy is a promising treatment strategy, but it can sometimes cause significant adverse events. The use of heated or baked egg might limit these, but current literature is insufficient to conclude about its efficacy.

Timing of complementary feeding for early childhood allergy prevention: An overview of systematic reviews

OBJECTIVE

To summarise and critically appraise systematic review (SR) evidence on the effects of timing of complementary feeding (CF) on the occurrence of allergic sensitisation and disease.

DESIGN

Overview of SRs. AMSTAR-2 and ROBIS were used to assess methodological quality and risk of bias (RoB) of SRs. RoB 2 Tool was used to assess RoB of primary randomised controlled trials (RCTs) (or extracted). The certainty of evidence (CoE) was assessed using GRADE. Findings were synthesised narratively.

DATA SOURCES

MEDLINE (via PubMed and Ovid), the Cochrane Library and Web of Science Core Collection (2010 to 27 February 2023).

ELIGIBILITY CRITERIA

SRs investigating the effects of timing of CF in infants or young children (0-3 years) on risk of developing food allergy (FA), allergic sensitisation, asthma, allergic rhinitis, atopic eczema and adverse events based on RCT evidence.

RESULTS

Eleven SRs were included. Only two SRs had low RoB; common issues were failure to report on funding of primary studies and failure to provide a list of excluded trials. Common limitations of included trials were lack of blinding of outcome assessment or detailed trial preregistration, and inadequate handling of high loss to follow up. Primary study overlap was very high for specific FA and slight to moderate for FA in general and other primary outcomes. Introducing specific foods (peanut, cooked egg) early probably reduces the risk of specific FA. Evidence for other allergic outcomes was mostly very uncertain and based on few primary studies. Trials varied regarding timing of CF, nature of complementary foods and population risk, which limited comparability between SRs.

CONCLUSIONS

For developing guidelines to support decision-making on the timing of CF as a preventive strategy, early introduction of specific foods (i.e. egg and peanut) seems promising and safe, whereas more extensive research is required regarding other allergic outcomes and potential adverse events.

Updates in Food Allergy Prevention in Children

Although significant evidence exists that feeding early has a role in the prevention of food allergy, this intervention in isolation may not be sufficient. Recent evidence highlights that early introduction of peanut specifically has had no significant impact on the populational prevalence of peanut allergy. Other factors that may contribute to food allergy prevention include regularity of ingestion once an allergen is introduced and consideration to the form in which the allergen is introduced (such as baked versus cooked egg). There are also many practicalities to early feeding and some discrepant viewpoints on these practicalities, which has led to poor implementation of early feeding strategies. In general, preemptive screening before food introduction is not recommended by most international allergy societies. Although there is little guidance to inform early introduction of allergens other than milk, egg, and peanut, the mechanism of sensitization is thought to be similar and there is no harm to early introduction. In terms of frequency and duration of feeding, there is little evidence to inform any concrete recommendations.

Early Introduction of Novel and Less-Studied Food Allergens in the Plant-Based Era: Considerations for US and EU Infant Formula Regulations

Early life feeding practices may affect the long-term health of individuals, particularly in terms of the development of non-communicable diseases, such as metabolic and allergic diseases. Accumulating evidence suggests that the interplay of breastfeeding and/or formula feeding followed by the introduction of solids plays a role in the occurrence of non-communicable diseases both in the short and long term. International food allergy guidelines recommend that breastfeeding women do not need to avoid food allergens and do not recommend any infant formula for allergy prevention. Guidelines regarding solid food introduction for food allergy prevention recommend the introduction of well-cooked eggs and peanuts around 4-6 months of age, and not to delay the introduction of other food allergens. There is also an increasing trend to feed infants a plant-based or plant-forward diet and have access to infant formulas based on plant-based ingredients. The use of novel plant-based infant formulas raises a few questions reviewed in this paper: (1) Do fortified, plant-based infant formulas, compliant with US Food and Drug Administration (FDA) regulations and European Food Safety Authority (EFSA) (European) guidelines, support adequate infant growth? (2) Are plant-based infant formulas suitable for the management of cow's milk allergy? (3) Does feeding with novel, plant-based infant formulas increase the risk of food allergies to the food allergens they contain? (4) Does feeding infants plant-based food allergens in early life increase the risk of allergic and severe allergic reactions? The review of the literature indicated that (1) plant-based formulas supplemented with amino acids and micronutrients to comply with FDA regulations and EFSA guidelines, evaluated in sufficiently powered growth studies, can support adequate growth in infants; (2) currently available plant-based infant formulas are suitable for the management of CMA; (3) an early introduction and continuous intake of food allergens are more likely to prevent food allergies than to increase their risk; and (4) an early introduction of food allergens in young infants is safe.

The SunBEAm birth cohort: Protocol design

Background

Food allergy (FA) and atopic dermatitis (AD) are common conditions that often present in the first year of life. Identification of underlying mechanisms and environmental determinants of FA and AD is essential to develop and implement effective prevention and treatment strategies. Objectives: We sought to describe the design of the Systems Biology of Early Atopy (SunBEAm) birth cohort.

Methods

Funded by the National Institute of Allergy and Infectious Diseases (NIAID) and administered through the Consortium for Food Allergy Research (CoFAR), SunBEAm is a US population-based, multicenter birth cohort that enrolls pregnant mothers, fathers, and their newborns and follows them to 3 years. Questionnaire and biosampling strategies were developed to apply a systems biology approach to identify environmental, immunologic, and multiomic determinants of AD, FA, and other allergic outcomes.

Results

Enrollment is currently underway. On the basis of an estimated FA prevalence of 6%, the enrollment goal is 2500 infants. AD is defined on the basis of questionnaire and assessment, and FA is defined by an algorithm combining history and testing. Although any FA will be recorded, we focus on the diagnosis of egg, milk, and peanut at 5 months, adding wheat, soy, cashew, hazelnut, walnut, codfish, shrimp, and sesame starting at 12 months. Sampling includes blood, hair, stool, dust, water, tape strips, skin swabs, nasal secretions, nasal swabs, saliva, urine, functional aspects of the skin, and maternal breast milk and vaginal swabs.

Conclusions

The SunBEAm birth cohort will provide a rich repository of data and specimens to interrogate mechanisms and determinants of early allergic outcomes, with an emphasis on FA, AD, and systems biology.

Infant egg consumption during introduction to solid food remains low in the United Kingdom but increases with infant age and a baby-led weaning approach

BACKGROUND

As a nutritious food-providing protein, essential fatty acids, vitamin D, iodine and choline eggs have historically been central to an infant weaning diet. However, food poisoning scares and allergy concerns have contributed to low consumption among infants aged 6-12 months.

METHODS

This paper presents a secondary data analysis of infant egg exposure and intake using three weaning data sets: a 7-day food frequency questionnaire (n = 297), a 24-h recall (n = 180) and a 3-day weighed food diary (n = 71). Egg introduction, frequency of consumption and intake in grams were analysed for infants aged 6-8, 9-10 and 11-12 months). Comparisons were made by whether infants were following a baby-led approach to weaning (where infants self-feed family foods) or a traditional approach where pureed foods are given alongside finger foods. Data were collected in the United Kingdom between 2015 and 2018.

RESULTS

Our data showed that despite introduction being recommended from the start of weaning at 6 months of age by the Department of Health, just 54% of infants aged 6-8 months had ever been offered eggs. Average egg intake was one to two times per week, increasing with age. However, in terms of frequency and grams consumed, our data suggest a small increase in consumption compared with previous research, although limitations of our smaller sample size should be noted. Finally, a baby-led approach was associated with increased exposure and consumption; baby-led infants consumed eggs twice as frequently as spoon-fed infants.

CONCLUSIONS

The findings have important implications for public health messaging and for supporting families in introducing solid foods.

Recent advances in cellular and molecular mechanisms of IgE-mediated food allergy

Food allergy is a public health issue the prevalence of which is steadily increasing. New discoveries have contributed to the understanding of the molecular and cellular mechanisms that lead to IgE-mediated food allergy. Novel scientific findings have defined roles for specific cell types, such as T follicular helper cells, in induction of high-affinity IgE by B cells. Also, not only mast cells and basophils contribute to food anaphylaxis, but also other cell types, such as neutrophils and macrophages. Elucidation of mechanisms involved in sensitization to food allergens through organs including the skin is key to deepening our understanding of the "dual exposure" hypothesis, which suggests that allergic sensitization is mainly acquired through inflamed skin while the oral route induces tolerance. This review considers the latest scientific knowledge about the molecular and cellular mechanisms of IgE-mediated food allergy. It reveals crucial components involved in the sensitization and elicitation phases and emerging approaches in anaphylaxis pathophysiology.

Timing of Allergenic Food Introduction and Risk of Immunoglobulin E-Mediated Food Allergy: A Systematic Review and Meta-analysis

Importance

Earlier egg and peanut introduction probably reduces risk of egg and peanut allergy, respectively, but it is uncertain whether food allergy as a whole can be prevented using earlier allergenic food introduction.

Objective

To investigate associations between timing of allergenic food introduction to the infant diet and risk of food allergy.

Data Sources

In this systematic review and meta-analysis, Medline, Embase, and CENTRAL databases were searched for articles from database inception to December 29, 2022. Search terms included infant, randomized controlled trial, and terms for common allergenic foods and allergic outcomes.

Study Selection

Randomized clinical trials evaluating age at allergenic food introduction (milk, egg, fish, shellfish, tree nuts, wheat, peanuts, and soya) during infancy and immunoglobulin E (IgE)-mediated food allergy from 1 to 5 years of age were included. Screening was conducted independently by multiple authors.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was used. Data were extracted in duplicate and synthesized using a random-effects model. The Grading of Recommendations, Assessment, Development, and Evaluation framework was used to assess certainty of evidence.

Main Outcomes and Measures

Primary outcomes were risk of IgE-mediated allergy to any food from 1 to 5 years of age and withdrawal from the intervention. Secondary outcomes included allergy to specific foods.

Results

Of 9283 titles screened, data were extracted from 23 eligible trials (56 articles, 13 794 randomized participants). There was moderate-certainty evidence from 4 trials (3295 participants) that introduction of multiple allergenic foods from 2 to 12 months of age (median age, 3-4 months) was associated with reduced risk of food allergy (risk ratio [RR], 0.49; 95% CI, 0.33-0.74; I2 = 49%). Absolute risk difference for a population with 5% incidence of food allergy was -26 cases (95% CI, -34 to -13 cases) per 1000 population. There was moderate-certainty evidence from 5 trials (4703 participants) that introduction of multiple allergenic foods from 2 to 12 months of age was associated with increased withdrawal from the intervention (RR, 2.29; 95% CI, 1.45-3.63; I2 = 89%). Absolute risk difference for a population with 20% withdrawal from the intervention was 258 cases (95% CI, 90-526 cases) per 1000 population. There was high-certainty evidence from 9 trials (4811 participants) that introduction of egg from 3 to 6 months of age was associated with reduced risk of egg allergy (RR, 0.60; 95% CI, 0.46-0.77; I2 = 0%) and high-certainty evidence from 4 trials (3796 participants) that introduction of peanut from 3 to 10 months of age was associated with reduced risk of peanut allergy (RR, 0.31; 95% CI, 0.19-0.51; I2 = 21%). Evidence for timing of introduction of cow's milk and risk of cow's milk allergy was very low certainty.

Conclusions and Relevance

In this systematic review and meta-analysis, earlier introduction of multiple allergenic foods in the first year of life was associated with lower risk of developing food allergy but a high rate of withdrawal from the intervention. Further work is needed to develop allergenic food interventions that are safe and acceptable for infants and their families.

[Early introduction of potentially allergenic foods in pediatric patients under six months of age]

OBJECTIVE

To review the available evidence on the early introduction of allergenic foods and the possible protection in the development of food allergy in later stages.

METHODS

An exploratory review of randomized clinical trials whose study population included infants less than 6 months of age at enrollment with or without a diagnosis of food allergy was conducted. For the purposes of this review, eggs, peanuts, and wheat were included as potentially allergenic foods. The following databases were consulted: Medline, EBSCO, OVID, Science Direct and JSTOR (Journal Storage), Scielo, LILACS, Redalyc and Imbiomed from August to December 2021.

RESULTS

429 articles were identified, 412 were excluded, and the final analysis included 9 studies that met the inclusion criteria. Six trials correspond to allergy to eggs, two to peanuts and one to wheat. The age of introduction differs in all trials. The earliest exposure was at 3.5 months and the latest at 5.5 months. The reduction in the risk of developing food allergy occurred in children at risk of allergy. Adverse reactions were common, particularly with the introduction of egg.

CONCLUSIONS

We found no evidence that early introduction (< 6 months of age) of allergenic foods reduces the risk of developing food allergy in infants without risk factors.

Quality of systematic reviews on timing of complementary feeding for early childhood allergy prevention

BACKGROUND

Only rigorously prepared analyses can provide the highest level of evidence to inform decision-making. Several recent systematic reviews (SRs) examined the hypothesis that the early introduction of specific allergenic complementary foods (CFs) to infants may lead to a lower incidence of one or more allergic outcomes. However, the methodological rigour and quality of reporting of SRs in this area has not yet been systematically evaluated.

METHODS

We comprehensively searched PubMed, Medline (Ovid), and Web of Science Core Collection on 13th January 2022, using a pre-specified and tested search syntax for SRs with RCT evidence on the early introduction of allergenic CFs as a means for allergy prevention in infants and children. We examined the quality and risk of bias (RoB) using AMSTAR-2 and ROBIS tools, examined adherence to the Preferred Reporting Items for SRs and Meta-Analyses (PRISMA), and checked whether certainty of the evidence was assessed.

RESULTS

Twelve SRs were included. Application of both tools resulted in similar overall judgements in terms of direction and extent for nine of the 12 SRs. Nine SRs were found to be of critically low to low quality according to AMSTAR-2 and to be at high RoB according to ROBIS. One SR received a moderate quality rating (AMSTAR-2) and high RoB rating (ROBIS). However, for two SRs, judgements between AMSTAR-2 and ROBIS were at stark variance. Only two SRs fully adhered to the PRISMA checklist. Six SRs evaluated the certainty of the body of RCT evidence. Several SRs failed to consider unpublished studies either by an explicit a priori exclusion or by inadequate search strategies.

CONCLUSIONS

Well-conducted SRs are important for decision-making and informing guideline development, the quality of their methodology should therefore be considered. The methodological rigour and the reporting quality of SRs on the timing of CF for allergy prevention must be improved.

REGISTRATION

https://osf.io/7cs4b .

A systematic review of quality and consistency of clinical practice guidelines on the primary prevention of food allergy and atopic dermatitis

Background and aims

With an increasing number of Clinical Practice Guidelines (CPGs) addressing primary prevention of food allergy and atopic dermatitis, it is timely to undertake a comprehensive assessment of the quality and consistency of recommendations and evaluation of their implementability in different geographical settings.

Methods

We systematically reviewed CPGs from 8 international databases and extensive website searches. Seven reviewers screened records in any language and then used the AGREE II and AGREE REX instruments to critically appraise CPGs published between January 2011 and April 2022.

Results

Our search identified 2138 relevant articles, of which 30 CPGs were eventually included. Eight (27%) CPGs were shortlisted based on our predefined quality criteria of achieving scores >70% in the "Scope and Purpose" and "Rigour of Development" domains of the AGREE II instrument. Among the shortlisted CPGs, scores on the "Applicability" domain were generally low, and only 3 CPGs rated highly in the "Implementability" domain of AGREE-REX, suggesting that the majority of CPGs fared poorly on global applicability. Recommendations on maternal diet and complementary feeding in infants were mostly consistent, but recommendations on use of hydrolysed formula and supplements varied considerably.

Conclusion

The overall quality of a CPG for Food Allergy and Atopic Dermatitis prevention did not correlate well with its global applicability. It is imperative that CPG developers consider stakeholders' preferences, local applicability, and adapt existing recommendations to each individual population and healthcare system to ensure successful implementation. There is a need for development of high-quality CPGs for allergy prevention outside of North America and Europe.

PROSPERO registration number

CRD42021265689.

Early, continuing exposure to cow's milk formula and cow's milk allergy: The COMEET study, a single center, prospective interventional study

BACKGROUND

Cow's milk allergy (CMA) is a common food allergy among infants. Information regarding the best timing for first exposure to cow's milk formula (CMF) is controversial and more evidence is required. Few randomized control trials have tried to accurately assess the timing and preventive effect of exposure to CMF on small cohorts.

OBJECTIVE

This study assessed the association between early, continuing exposure to CMF on the basis of the parents' preferences and the development of immunoglobulin E (IgE)-mediated CMA in a large birth cohort.

METHODS

Newborns were prospectively recruited shortly before birth and divided into 2 groups according to parental feeding preference for the first 2 months of life: (1) exclusive breastfeeding (EBF); or (2) at least 1 meal of CMF (with or without breastfeeding) daily. Infants were followed up monthly until the age of 12 months.

RESULTS

Among 1992 infants participating in the study, 1073 (53.86%) were in the EBF group until 2 months of age. IgE-mediated CMA was confirmed in 0.85% (n = 17); all were in the EBF group. Within this group, the prevalence of IgE-mediated CMA was 1.58% compared with 0 in the other groups (relative risk, 29.98; P < .001). Post hoc analysis revealed IgE-mediated CMA prevalence of 0.7% in the per-protocol EBF group vs 3.27% among breastfed infants who were exposed to a small amount of CMF during the first 2 months of life. A family atopic background did not affect the results.

CONCLUSION

Early, continuing exposure to CMF from birth has the potential to prevent the development of IgE-mediated CMA and should be encouraged. However, the exposure needs to be consistent because occasional exposure increases the risk of developing IgE-mediated CMA and should be avoided.

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

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

Frequency of Infant Egg Consumption and Risk of Maternal-Reported Egg Allergy at 6 Years

BACKGROUND

Recent research suggests that early egg introduction during infancy may help to prevent egg allergy development. However, the infant egg consumption frequency that is sufficient to induce this immune tolerance remains uncertain.

OBJECTIVES

We examined the associations between the infant egg consumption frequency and maternal-reported child egg allergy at 6 y.

METHODS

We analyzed data of 1252 children from the Infant Feeding Practices Study II (2005-2012). Mothers reported the frequency of infant egg consumption at 2, 3, 4, 5, 6, 7, 9, 10, and 12 mo old. Mothers reported the status of their child's egg allergy at the 6-y follow-up. We used Fisher exact test, Cochran-Armitage Trend Test, and log Poisson regression models to compare 6-y egg allergy risk by the frequency of infant egg consumption.

RESULTS

The risk of maternal-reported egg allergy at 6 y significantly (P-trend = 0.004) decreased with infant egg consumption frequency at 12 mo: 2.05% (11/537) for infants not consuming eggs, 0.41% (1/244) for those consuming eggs <2 times per wk, and 0.21% (1/471) for those consuming eggs ≥2 times per wk. A similar but nonsignificant trend (P-trend=0.109) was observed for egg consumption at 10 mo (1.25%, 0.85%, and 0%, respectively). After adjusting for socioeconomic confounders, breastfeeding, complementary food introduction, and infant eczema, infants who consumed eggs ≥2 times per wk at 12 mo had a significantly lower RR of maternal-reported egg allergy at 6 y (confounder-adjusted RR: 0.11; 95% CI: 0.01, 0.88; P = 0.038), whereas those who consumed <2 times per wk (confounder-adjusted RR: 0.21; 95% CI: 0.03, 1.67; P = 0.141) did not have a significantly lower risk than those who did not consume eggs at all.

CONCLUSIONS

Consumption of eggs ≥2 times per wk in late infancy is associated with a reduced risk of developing egg allergy later in childhood.

Delayed egg introduction beyond infancy and increased egg allergy risk in childhood

AIM

Egg is a major food allergen in childhood. Recent studies suggest that early introduction of allergenic foods can decrease the risk of developing egg allergy. The impact of early egg introduction in the general population is unclear. We examined associations between age of infant egg introduction and childhood egg allergy outcomes in a general population.

METHODS

The study population consisted of 1217 neonates from Project Viva, a longitudinal pre-birth cohort in eastern Massachusetts area, USA. Mothers reported age of infant egg introduction and child egg allergy using questionnaires and specific IgE to egg white was assayed. We estimated associations between age of infant egg introduction and egg allergy outcomes using Log-binomial regression models, adjusting for socio-demographics and health confounders.

RESULTS

Egg allergy at 2 years was significantly higher (8.0% vs. 1.4%, P < 0.0001) in children who had delayed egg introduction beyond infancy, compared with children who were introduced to egg during infancy (adjusted relative risk or aRR 7.58; 95% CI 3.08, 18.61). At 12 years, the risk of egg allergy remained significantly higher (3.9% vs. 1.1%, P = 0.048) in children with delayed egg introduction compared with children introduced to egg during infancy (aRR 4.07; 95% CI 1.20, 13.87).

CONCLUSIONS

Infants with delayed introduction of eggs after 12 months had increased risk of egg allergy in childhood (2 years) and the relationship persisted in early adolescence (12 years). Our findings suggest that introduction to eggs before 12 months could contribute to the prevention of egg allergy.

Nutritional Management of Children with Food Allergies

Purpose of the Review

The purpose of the review is to review the evidence for the nutritional management of paediatric food allergy and provide a practical approach for healthcare professionals working in this area.

Recent Findings

Dietary elimination remains the mainstay for management of food allergies in children. However, the elimination of food allergens increases the risk for growth faltering, micronutrient deficiencies and feeding difficulties. Breastmilk remains the ideal source of nutrition for infants, but when not available, the vast majority will tolerate an extensively hydrolysed formula, and rice hydrolysate has also been suggested as a suitable alternative. Only in severe cases, including anaphylaxis, eosinophilic oesophagitis and growth faltering, is an amino acid formula indicated. The early introduction of peanut and egg and avoiding the delay in the introduction of other allergens, when not already allergic, has been highlighted by recent studies.

Summary

Whilst the elimination of allergens increases the risk of developing poor growth, micronutrient deficiencies and feeding difficulties, optimal, early dietary input, including advice on active introduction of allergens and alternative feeds, ideally from a registered dietitian/nutritionist, may be prevent and improve outcomes.

How a Family History of Allergic Diseases Influences Food Allergy in Children: The Japan Environment and Children's Study

The influence of family allergic history on food allergy in offspring in Japan is unknown. We analyzed data from a nationwide birth cohort study using logistic regression models to examine the associations of maternal, paternal, and both parental histories of allergic diseases (food allergy, atopic dermatitis, asthma, and rhinitis) with their child’s food allergy at 1.5 and 3 years of age. This analysis included 69,379 singleton full-term mothers and 37,179 fathers and their children. All parental histories of allergic diseases showed significant positive associations with their child’s food allergy. When both parents had a history of allergic diseases, the adjusted odds ratio (aOR) tended to be higher than when either parent had allergic diseases (p for trend < 0.0001). The highest aOR was detected when both parents had food allergy (2.60; 95% confidential interval, 1.58−4.27), and the aOR was 1.71 when either parent had food allergy (95% confidential interval, 1.54−1.91). The aORs were attenuated but still had significant positive associations after adjusting for the child’s atopic dermatitis, a risk factor for allergy development. In conclusion, all parental allergic diseases were significantly positively associated with their child’s food allergy. The effect of family history showed a stepwise increase in risk from either parent to both parents, and the highest risk of allergic disease was a parental history of food allergy.

Predictors and biomarkers of food allergy and sensitization in early childhood

OBJECTIVE

To review existing literature on the early risk factors for and biomarkers of food allergy (FA) and food sensitization (FS) and highlight opportunities for future research that will further the understanding of FA pathogenesis in infancy and toddlerhood.

DATA SOURCES

PubMed search of English-language articles related to FA and atopic disease.

STUDY SELECTIONS

Human studies with outcomes related to FA, FS, and other atopic disease in childhood were selected and reviewed. Studies published after 2015 were prioritized.

RESULTS

The prevalence of FA has greatly increased in recent decades and is now a global public health concern. A complex network of early life risk factors has been associated with development of FA and FS in childhood. Food allergy has a genetic component, but recent evidence suggests that interactions between risk alleles and other environmental exposures are important for disease pathogenesis, potentially through epigenetic mechanisms. Lifestyle factors, such as delivery mode, antibiotic use, and pet exposure also influence FA risk, which may be through their effect on the early life gut microbiome. How these early life risk factors, along with route and timing of antigen exposure, collectively target the developing immune system remains an ongoing and important area of study.

CONCLUSION

The current body of evidence emphasizes the first 1000 days of life as a critical period for FA development. More observational studies and adequately powered clinical trials spanning early pregnancy through childhood are needed to identify novel biomarkers and risk factors that can predict susceptibility toward or protection against FA.

How primary care providers can help prevent food allergies

PURPOSE OF REVIEW

IgE-mediated food allergy rates have increased in recent decades, yet treatment options remain limited. Prevention strategies are thus essential. We will review recent research and consensus guidelines for food allergy prevention.

RECENT FINDINGS

Research has continued to support that early introduction of allergens via the gastrointestinal tract induces tolerance and prevents development of food allergy. In contrast, allergen sensitization may occur via transcutaneous allergen exposure. This is supported by research that shows a decreased risk of food allergy with aggressive treatment of atopic dermatitis. More recent research suggests that transcutaneous sensitization could also be facilitated by frequent emollient use in the absence of atopic dermatitis but definitive research is lacking. Murine models have shown a likely role of dysbiosis, or disruption of the body's normal healthy microbiome, in development of food allergy, yet human studies have yet to show a conclusive benefit of probiotics in the prevention of food allergy.

SUMMARY

Important approaches for food allergy prevention are: introduction of peanut and cooked egg at 4-6 months, early introduction of other allergenic foods, and early diagnosis and treatment of atopic dermatitis (because of a predisposition to food sensitization through the damaged skin barrier). More research is needed to clarify the role, if any, of emollient use and probiotics.

Relevance of Early Introduction of Cow’s Milk Proteins for Prevention of Cow’s Milk Allergy

Food allergy incidence has increased worldwide over the last 20 years. For prevention of food allergy, current guidelines do not recommend delaying the introduction of allergenic foods. Several groundbreaking studies, such as the Learning Early About Peanut Allergy study, showed that the relatively early introduction of this allergenic food between 4–6 months of age reduces the risk of peanut allergy. However, less is known about the introduction of cow’s milk, as many children already receive cow’s-milk-based formula much earlier in life. This can be regular cow’s milk formula with intact milk proteins or hydrolyzed formulas. Several recent studies have investigated the effects of early introduction of cow’s-milk-based formulas with intact milk proteins on the development of cow’s milk allergy while breastfeeding. These studies suggest that depending on the time of introduction and the duration of administration of cow’s milk, the risk of cow’s milk allergy can be reduced (early introduction) or increased (very early introduction followed by discontinuation). The aim of this narrative review is to summarize these studies and to discuss the impact of early introduction of intact cow’s milk protein—as well as hydrolyzed milk protein formulas—and the development of tolerance versus allergy towards cow’s milk proteins.

PrEggNut Study: protocol for a randomised controlled trial investigating the effect of a maternal diet rich in eggs and peanuts from <23 weeks' gestation during pregnancy to 4 months' lactation on infant IgE-mediated egg and peanut allergy outcomes

INTRODUCTION

Clinical studies supported by immunological data indicate early life intervention strategies to be promising in reducing the growing global burden of food allergies. The events that predispose to food allergy, including the induction of allergen-specific immune responses, appear to be initiated early in development. Early exposure to food allergens in utero and via breast milk is likely to be important in initiating oral tolerance. We aim to determine the effectiveness of higher maternal food allergen consumption during pregnancy and lactation on infant food allergy outcomes.

METHODS AND ANALYSIS

This is a multisite, parallel, two-arm (1:1 allocation), single-blinded (outcome assessors, statistical analyst and investigators), randomised controlled trial. Pregnant women (<23 weeks' gestation) whose (unborn) infants have at least two biological family members (mother, father or siblings) with medically diagnosed allergic disease are eligible to participate. After obtaining written informed consent, pregnant women are randomised to either a high egg and peanut diet (at least 6 eggs and 60 peanuts per week) or standard (low) egg and peanut diet (no more than 3 eggs and 30 peanuts per week). The women are asked to follow their allocated diet from <23 weeks' gestation to 4 months' lactation. The primary outcome is food challenge proven IgE-mediated egg and/or peanut allergy in the infants at 12 months of age. Key secondary outcomes include infant sensitisation to egg and/or peanut and infant eczema. Our target sample size is 2136 women. Analyses will be performed on an intention-to-treat basis according to a pre-specified statistical analysis plan.

ETHICS AND DISSEMINATION

Ethical approval has been granted from the Women's and Children's Health Network Human Research Ethics Committee (approval number HREC/18/WCHN/42). Trial results will be presented at scientific conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry ACTRN12618000937213.

Dietary exposures and allergy prevention in high-risk infants

Infants at high risk for developing a food allergy have either an atopic condition (such as eczema) themselves or an immediate family member with such a condition. Breastfeeding should be promoted and supported regardless of issues pertaining to food allergy prevention, but for infants whose mothers cannot or choose not to breastfeed, using a specific formula (i.e., hydrolyzed formula) is not recommended to prevent food allergies. When cow's milk protein formula has been introduced in an infant's diet, make sure that regular ingestion (as little as 10 mL daily) is maintained to prevent loss of tolerance. For high-risk infants, there is compelling evidence that introducing allergenic foods early-at around 6 months, but not before 4 months of age-can prevent common food allergies, and allergies to peanut and egg in particular. Once an allergenic food has been introduced, regular ingestion (e.g., a few times a week) is important to maintain tolerance. Common allergenic foods can be introduced without pausing for days between new foods, and the risk for a severe reaction at first exposure in infancy is extremely low. Pre-emptive in-office screening before introducing allergenic foods is not recommended. No recommendations can be made at this time about the role of maternal dietary modification during pregnancy or lactation, or about supplementing with vitamin D, omega 3, or pre- or probiotics as means to prevent food allergy.

Egg Allergy in Children and Weaning Diet

Eggs are a fundamental food in the human diet, and together with cow’s milk, they are the most common food allergen. This work highlights the main nutritional characteristics of eggs to show how their absence from a child’s diet can constitute a serious deficiency. We then analyze the risk factors that facilitate the onset of egg allergy. The third part of the paper reports possible interventions to lower the appearance of food allergy that have been occurred in trials. The last part of the paper is a synthesis of this research study that has been taken from several of the latest guidelines or from position papers.

Early introduction of very small amounts of multiple foods to infants: A randomized trial

BACKGROUND

We investigated whether multiple food allergies could be safely prevented by simultaneously administering very small amounts of multiple foods.

METHODS

Infants 3-4 months old with atopic dermatitis from 14 primary care pediatric clinics in Japan were enrolled in this randomized, placebo-controlled trial. The infants were administered either mixed allergenic food powder (MP) containing egg, milk, wheat, soybean, buckwheat, and peanuts, or placebo powder (PP). The amount of powder was increased in a stepwise manner on weeks 2 and 4, and continued until week 12. The occurrence of food allergy episodes after powder intervention was assessed at 18 months old. This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry (number UMIN000027837).

RESULTS

A total of 163 participants were randomly allocated to either the MP group (n = 83) or the PP group (n = 80). The incidence of food allergy episodes by 18 months was significantly different between the MP and PP groups (7/83 vs. 19/80, respectively; risk ratio 0.301 [95% CI 0.116-0.784]; P = 0.0066). Egg allergies were reduced in the MP group. In addition, food allergy episodes from any of the other five foods were significantly reduced, although the reductions in those due to individual foods were not significant.

CONCLUSIONS

Gradually increasing the intake of very small amounts of multiple foods in early infancy can safely reduce the incidence of egg allergies. Other foods may also suppress food allergies, but no definitive conclusions could be reached.

Current Insights into Atopic March

The incidence of allergic diseases is increasing, and research on their epidemiology, pathophysiology, and the prevention of onset is urgently needed. The onset of allergic disease begins in infancy with atopic dermatitis and food allergy and develops into allergic asthma and allergic rhinitis in childhood; the process is defined as “atopic march”. Atopic march is caused by multiple immunological pathways, including allergen exposure, environmental pollutants, skin barrier dysfunction, type 2 inflammation, and oxidative stress, which promote the progression of atopic march. Using recent evidence, herein, we explain the involvement of allergic inflammatory conditions and oxidative stress in the process of atopic march, its epidemiology, and methods for prevention of onset.

Clinical Manifestations of Pediatric Food Allergy: a Contemporary Review

Food allergies (FAs) are an emerging health care issue, and a "second wave of the allergy epidemic" was named. There are extensive data that documented the prevalence rate as high as approximately 10%. FAs are immunological adverse reactions, including IgE-mediated mechanisms, cell-mediated mechanisms, or mixed IgE- and cell-mediated mechanisms. A diagnosis of FA is made by specific symptoms encounter with food, detailed past history, sensitization tests, and oral food challenges (OFCs) if necessary. The component-resolved diagnostics (CRD) test can distinguish true or cross-reaction. "Minimal elimination" from the results of CRD and OFC could avoid unnecessary food restriction. Strict food limitation is harsh and stressful on patients and their families. Children with FAs experience a higher rate of post-traumatic stress symptoms (PTSS) and bullying than others. In the last 20 years, oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) are treatment strategies. OIT and EPIT are the most two encouraging treatments for FA. This review aims to introduce FAs in diverse clinical disorders, new perspectives, and their practical implications in diagnosing and treating FA.

Overview of oral tolerance induction for prevention of food allergy-Where are we now?

Oral tolerance induction through early introduction of allergenic food has proven effective in randomized controlled trials. This new approach to weaning has been incorporated into many national and international infants' feeding guidelines. However, there are questions that require further discussion, such as, which foods should be introduced early, should the intervention be targeted to infants at high-risk or to the general population, and what is the ideal timing for early food introduction. This review examines the extent to which recent trials address these critical questions and highlights areas where further research is required.

Allergen shedding in human milk: Could it be key for immune system education and allergy prevention?

In addition to being a source of nutrients for the developing newborn, human milk contains thousands of bioactive compounds, which influence infant health in the short-term as exemplified by its major benefits on infectious disease prevention. Many of the human milk compounds also have the required characteristics to instruct immune development and guide long-term health. Prebiotics, probiotics, and varied antimicrobial molecules all have the potential to shape the composition and function of the establishing gut microbiota, which is known to be a major determinant of immune function. Another and less explored way human milk can instruct long-term immunity is through antigen shedding. Here, we will review the evidence that antigens from maternal environment and more specifically from allergen sources are found in human milk. We will discuss data from rodent models and birth cohorts showing that allergen shedding in breast milk may influence long-term allergy risk. We will uncover the variables that may underlie heterogeneity in oral tolerance induction and allergy prevention in children breast-fed by allergen-exposed mothers. We will focus on the parameters that control antigen transfer to breast milk, on the unique biological characteristics of allergens in breast milk, and on the milk bioactive compounds that were found to influence immune response in offspring. We propose this understanding is fundamental to guide maternal interventions leading to lifelong allergen tolerance.

Update of the S2k guideline on the management of IgE-mediated food allergies

Not available.

Early Introduction of Food Allergens and Risk of Developing Food Allergy

There is increasing evidence that early introduction of allergenic foods may decrease the risk of developing IgE-mediated food allergy. Patterns of food introduction before the 2015 publication of the Learning Early about Peanut Allergy (LEAP) trial are not well-studied, but are important as a baseline for evaluating subsequent changes in infant feeding practices and potentially food allergy. We performed a retrospective longitudinal study using data from a multicenter cohort of infants hospitalized with bronchiolitis between 2011–2014. The primary outcomes were IgE-mediated egg or peanut allergy by age 3 years. Of 770 participants included in the analysis, 635 (82%) introduced egg, and 221 (27%) introduced peanut by age 12 months per parent report. Four participants had likely egg allergy, and eight participants had likely peanut allergy by age 3 years. Regular infant egg consumption was associated with less egg allergy. The association was suggestive for infant peanut consumption with zero peanut allergy cases. Overall, our results suggest that early introduction of peanut was uncommon before 2015. Although limited by the small number of allergy cases, our results suggest that early introduction of egg and peanut are associated with a decreased risk of developing food allergy, and support recent changes in practice guidelines.

EAACI guideline: Preventing the development of food allergy in infants and young children (2020 update)

BACKGROUND

This guideline from the European Academy of Allergy and Clinical Immunology (EAACI) recommends approaches to prevent the development of immediate-onset / IgE-mediated food allergy in infants and young children. It is an update of a 2014 EAACI guideline.

METHODS

The guideline was developed using the AGREE II framework and the GRADE approach. An international Task Force with representatives from 11 countries and different disciplinary and clinical backgrounds systematically reviewed research and considered expert opinion. Recommendations were created by weighing up benefits and harms, considering the certainty of evidence and examining values, preferences and resource implications. The guideline was peer-reviewed by external experts, and feedback was incorporated from public consultation.

RESULTS

All of the recommendations about preventing food allergy relate to infants (up to 1 year) and young children (up to 5 years), regardless of risk of allergy. There was insufficient evidence about preventing food allergy in other age groups. The EAACI Task Force suggests avoiding the use of regular cow's milk formula as supplementary feed for breastfed infants in the first week of life. The EAACI Task Force suggests introducing well-cooked, but not raw egg or uncooked pasteurized, egg into the infant diet as part of complementary feeding. In populations where there is a high prevalence of peanut allergy, the EAACI Task Force suggests introducing peanuts in an age-appropriate form as part of complementary feeding. According to the studies, it appears that the most effective age to introduce egg and peanut is from four to 6 months of life. The EAACI Task Force suggests against the following for preventing food allergy: (i) avoiding dietary food allergens during pregnancy or breastfeeding; and (ii) using soy protein formula in the first 6 months of life as a means of preventing food allergy. There is no recommendation for or against the following: use of vitamin supplements, fish oil, prebiotics, probiotics or synbiotics in pregnancy, when breastfeeding or in infancy; altering the duration of exclusive breastfeeding; and hydrolysed infant formulas, regular cow's milk-based infant formula after a week of age or use of emollients.

CONCLUSIONS

Key changes from the 2014 guideline include suggesting (i) the introduction of peanut and well-cooked egg as part of complementary feeding (moderate certainty of evidence) and (ii) avoiding supplementation with regular cow's milk formula in the first week of life (low certainty of evidence). There remains uncertainty in how to prevent food allergy, and further well-powered, multinational research using robust diagnostic criteria is needed.

Optimizing Patient Care in Egg Allergy Diagnosis and Treatment

Egg allergy occurs frequently in childhood with a reported prevalence of 1.3–1.6%. Providing optimal care to egg-allergic patients requires knowledge of the most up-to-date developments in both diagnosis and management, as well as effective communication skills, which will engage the patient in the shared decision-making process. This review aims to provide up-to-date information on egg allergy and also serve as a concise guide on optimal patient diagnosis and management. The field of food allergy has seen multiple advances in recent years, including use of component resolved diagnostics, early egg introduction into the infant diet as a way of preventing egg allergy, baked egg introduction and oral immunotherapy as a form of active therapy. Faced with a variety of options and treatment paths, it is important to ensure that patients and families taking part in the decision-making process have fully understood the potential outcomes and trade-offs and can undertake a detailed discussion of all options that are available to them. Shared decision-making remains the cornerstone of optimal patient care.

Differences in oral food challenge reaction severity based on increasing age in a pediatric population

BACKGROUND

Food allergy reactions range from mild to severe with differences in age appearing to be an important factor associated with reaction severity.

OBJECTIVE

To define differences in oral food challenge (OFC) reaction severity in pediatric patients from infancy to adolescence using objective clinical outcomes and standardized reaction grading tools.

METHODS

Retrospective review of all positive OFC results at 2 large institutions between September 2016 and February 2019. Reaction severity was defined by presence of cardiovascular, neurologic, lower respiratory, or laryngeal symptoms, epinephrine requirement, and grading using 2 established food allergy reaction scales.

RESULTS

Infants and toddlers had fewer reactions involving cardiovascular, neurologic, lower respiratory, or laryngeal symptoms compared with older age groups. Epinephrine was also required less frequently during reactions in infants and toddlers, compared with older age groups. There was no difference in reaction severity in infants and toddlers based on clinical history of eczema. Increasing age was significantly correlated with increased epinephrine requirement (R² = 0.12, P = .002), elevated Consortium of Food Allergy Research score (R² = .012, P = .003), and approached significance for increased Practical Allergy score (R² = .005, P = .05). History of asthma and sesame allergy were identified to be positively correlated with more severe reactions.

CONCLUSION

Infants and young toddlers have less severe reactions during OFCs compared with older age groups supporting early food introduction practices. In children under 12 months of age, severe reactions are most rare calling into question screening practices using specific allergy testing before food introduction. Standardized reaction grading tools may be valuable instruments to categorize reaction severity during OFCs.

Food Allergy Prevention: More Than Peanut

Given an apparent increase in food allergies worldwide, the focus on prevention strategies has intensified. Following the Learning Early About Peanut study, there is now a widespread acceptance that peanut should be introduced promptly into the diet of high-risk infants. However, most food allergies are caused by triggers other than peanut and additional prevention strategies are being evaluated. The appreciation of the role of an impaired skin barrier in the process of food sensitization and subsequent allergy has led to a spectrum of dermatologically orientated studies. Other prevention strategies address the role of the microbiome, dietary components, and other modifiable risk factors. With regard to early introduction of foods other than peanut, studies are heterogeneous in design and governmental and professional society response to the early introduction trials has varied, ranging from new guidelines confining advice specifically to peanut, to ones recommending prompt introduction of a broad spectrum of allergenic foods. Much remains to be determined with regard to the acceptability and uptake of the new guidelines and their impact on infant feeding behavior and food allergy outcomes. This review discusses the panoply of prevention approaches, their promise, and limitations.

Longitudinal egg-specific regulatory T- and B-cell development: Insights from primary prevention clinical trials examining the timing of egg introduction

BACKGROUND

Egg allergy affects almost 1 in 10 Australian infants. Early egg introduction has been associated with a reduced risk in developing egg allergy; however, the immune mechanisms underlying this protection remain unclear.

OBJECTIVE

To examine the role of regulatory immune cells in tolerance induction during early egg introduction.

METHODS

Cryopreserved peripheral blood mononuclear cells (PBMC) were obtained from infants from 2 randomized controlled trials of early introduction of egg for the primary prevention of egg allergy; BEAT (at 12 months, n = 42) and STEP (at 5 months n = 82; 12 months n = 82) study cohorts. In vitro ovalbumin-stimulated PBMC were analyzed by flow cytometry for presence of ovalbumin-specific regulatory T cells, using activation markers, FoxP3, and IL-10 expression. Ovalbumin-specific regulatory B cells were identified by co-expression of fluorescence-conjugated ovalbumin and IL-10.

RESULTS

Specific, age-dependent expansion of ovalbumin-specific regulatory T cells was only observed in infants who (a) had early egg introduction and (b) did not have egg allergy at 12 months. This expansion was blunted or impaired in children who did not undergo early egg introduction and in those with clinical egg allergy at 12 months. Infants with egg allergy at 12 months of age also had reduced frequency of ovalbumin-specific regulatory B cells compared to egg-tolerant infants.

CONCLUSION

Early egg introduction and clinical tolerance to egg were associated with expansion of ovalbumin-specific T and B regulatory cells, which may be an important developmental process for tolerance acquisition to food allergens.

Tackling Food Allergy in Infancy

Atopic dermatitis and food allergy are the most common allergic conditions affecting the infant population. Both immunoglobulin E (IgE)-mediated and non-IgE-mediated food allergy are seen in infancy. Early life feeding guidelines have changed dramatically over the past 30 years, more recently because of an improved understanding of IgE-mediated food allergy. This article focuses on identification, diagnosis, management, and prevention of food allergy in the infant population.

Array-based measurements of aero-allergen-specific IgE correlate with skin-prick test reactivity in asthma regardless of specific IgG4 or total IgE measurements

Skin prick testing (SPT) and measurement of serum allergen-specific IgE (sIgE) are used to investigate asthma and other allergic conditions. Measurement of serum total IgE (tIgE) and allergen-specific IgG4 (sIgG4) may also be useful. The aim was to ascertain the correlation between these serological parameters and SPT. Sera from 60 suspected asthmatic patients and 18 healthy controls were assayed for sIgE and sIgG4 reactivity against a panel of 70 SPT allergen preparations, and for tIgE. The patients were also assessed by skin prick tests for reactivity to cat, dog, house dust mite and grass allergens. Over 50% of the patients had tIgE levels above the 75th percentile of the controls. 58% of patients and 39% of controls showed sIgE reactivity to ≥1 allergen. The mean number of allergens detected by sIgE was 3.1 in suspected asthma patients and 0.9 in controls. 58% of patients and 50% of controls showed sIgG4 reactivity to ≥1 allergen. The mean number of allergens detected by sIgG4 was 2.5 in patients and 1.7 in controls. For the patients, a strong correlation was observed between clinical SPT reactivity and serum sIgE levels to cat, dog, house dust mite (HDM) and grass allergens. SPT correlations using sIgE/sIgG4 or sIgE/tIgE ratios were not markedly higher. The measurement of serum sIgE by microarray using SPT allergen preparations showed good correlation with clinical SPT reactivity to cat, dog, HDM and grass allergens. This concordance was not improved by measuring tIgE or sIgG4.

Evaluation of the introduction of allergen-containing foods: Feeding Infants and Toddlers Study 2016

BACKGROUND

Guidelines on the early introduction of allergen-containing foods are evolving; however, little national data exist defining current allergen-feeding practices.

OBJECTIVE

To investigate the consumption rates of foods containing egg and peanut among infants and toddlers before the guideline changes in 2017.

METHODS

The Feeding Infants and Toddlers Study 2016 was conducted nationally among 3235 caregivers with a child under 4 years of age. The 24-hour dietary recalls were reviewed for peanut or egg ingredients. Participants were categorized as "consuming peanut or egg-containing foods" or "not consuming peanut or egg-containing foods." Data on physician-diagnosed food allergies and avoidance were collected.

RESULTS

The consumption rates of peanut- and egg-containing foods were low. For the age group of 4 to 5.9 months, 0.3% reported peanut consumption and 2.4% reported egg consumption. For the age group of 6 to 8.9 months, 0.9% reported eating peanut-containing foods and 13.0% egg, and for the age group of 9 to 11.9 months, 5.5% were consuming peanut-containing foods and 33.2% egg-containing foods. Peanut or egg ingredients were identified in the diet of children whose caregivers reported avoidance.

CONCLUSION

Before the publication of the 2017 Addendum Guidelines for the Prevention of Peanut Allergy, there were low rates of reported peanut consumption across the study population with less than 1% of any age group before 9 months of age and less than 6% in any age group before 12 months of age consuming peanut on the 24-hour recall day. In addition, reported egg consumption was low and increased with age. These results serve as an important baseline comparison for future studies evaluating the implementation and impact of early peanut and egg introduction.

The impact of provider training on patient education for pediatric early food introduction

BACKGROUND

Pediatric food allergies (FAs) present significant health and economic problems. Currently, there are no cures for FAs. Recent studies suggest that early introduction (EI), between 4 and 6 months of age, of commonly allergenic foods (CAFs) may reduce the risk of developing FAs. This contradicts the current standard of care, food avoidance.

LOCAL PROBLEM

A federally qualified health center saw 894 patients aged 0-24 months during a 12-month period with only 18.9% receiving nutrition education. New dietary recommendations to prevent FA were not in place.

METHODS

A retrospective chart review was used to evaluate use of an order set with patient education on EI to CAFs in the electronic medical record (EMR).

INTERVENTIONS

Providers attended training on EI to CAFs and use of the EMR order set. Data were collected on the use of the order set over a 3-month period.

RESULTS

Provider training significantly improved knowledge of FA as well as EI guidelines. After 3 months of implementation, 25.95% of eligible encounters contained the EI order set; 52% of patients received the order set during the measurement period. In the impact population, patients 4-12 months of age, 74.55% of patients received the order set.

CONCLUSIONS

Evidence-based clinical content in EMR order sets coupled with provider training ensure clinical decision support in identifying, monitoring, and optimizing quality care standards.