The impact of government advice to pregnant mothers regarding peanut avoidance on the prevalence of peanut allergy in United Kingdom children at school entry

Biomarkers of peanut allergy in children over time

BACKGROUND

Various biomarkers are used to define peanut allergy (PA). We aimed to observe changes in PA resolution and persistence over time comparing biomarkers in PA and peanut sensitised but tolerant (PS) children in a population-based cohort.

METHODS

Participants were recruited from the EAT and EAT-On studies, conducted across England and Wales, and were exclusively breastfeed babies recruited at 3 months old and followed up until 7-12 years old. Clinical characteristics, skin prick test (SPT), sIgE to peanut and peanut components and mast cell activation tests (MAT) were assessed at 12 months, 36 months and 7-12 years. PA status was determined at the 7-12 year time point.

RESULTS

The prevalence of PA was 2.1% at 7-12 years. Between 3 and 7-12 year, two children developed PA and one outgrew PA. PA children had larger SPT, higher peanut-sIgE, Ara h 2-sIgE and MAT (all p < .001) compared to PS children from 12 months onwards. SPT, peanut-sIgE, Ara h 2-sIgE and MAT between children with persistent PA, new PA, outgrown PA and PS were statistically significant from 12 months onwards (p < .001). Those with persistent PA had SPT, peanut-sIgE and Ara h 2-sIgE that increased over time and MAT which was highest at 36 months. New PA children had increased SPT and peanut-sIgE from 36 months to 7-12 years, but MAT remained low. PS children had low biomarkers across time.

CONCLUSIONS

In this cohort, few children outgrow or develop new PA between 36 months and 7-12 years. Children with persistent PA have raised SPT, peanut-sIgE, Ara h 2-sIgE and MAT evident from infancy that consistently increase over time.

Prevalence estimates of eight big food allergies in Europe: Updated systematic review and meta-analysis

In 2014, the European Academy of Allergy and Clinical Immunology published prevalence estimates for food allergy (FA) and food sensitization (FS) to the so-called eight big food allergens (i.e. cow's milk, egg, wheat, soy, peanut, tree nuts, fish and shellfish) in Europe for studies published between 2000 and 2012. The current work provides 10-year updated prevalence estimates for these food allergens. A protocol was registered on PROSPERO before starting the research (reference number CRD42021266657). Six databases were searched for studies published 2012-2021, added to studies published up to 2012, resulting in a total of 93 studies. Most studies were graded as at moderate risk of bias. The overall pooled estimates for all age groups of self-reported lifetime prevalence were as follows: cow's milk (5.7%, 95% confidence interval 4.4-6.9), egg (2.4%, 1.8-3.0), wheat (1.6%, 0.9-2.3), soy (0.5%, 0.3-0.7), peanut (1.5%, 1.0-2.1), tree nuts (0.9%, 0.6-1.2), fish (1.4%, 0.8-2.0) and shellfish (0.4%, 0.3-0.6). The point prevalence of food challenge-verified allergy were as follows: cow's milk (0.3%, 0.1-0.5), egg (0.8%, 0.5-1.2), wheat (0.1%, 0.01-0.2), soy (0.3%, 0.1-0.4), peanut (0.1%, 0.0-0.2), tree nuts (0.04%, 0.02-0.1), fish (0.02%, 0.0-0.1) and shellfish (0.1%, 0.0-0.2). With some exceptions, the prevalence of allergy to common foods did not substantially change during the last decade; variations by European regions were observed.

Maternal Diet and Infant Risk of Eczema and Food Allergy: A Systematic Review

A significant portion of the pediatric population is affected by allergy diseases, which have become a worldwide public health concern. Could maternal diet during pregnancy or breastfeeding influence allergy outcomes in offspring? If this cause-and-effect relationship exists, it will be simpler to design prevention strategies to reduce the incidence of allergic disorders in children, reduce costs to the public health system and to parents, and improve the quality of life of allergic children and their parents. In this systematic review, we will visit the literature from January 2019 to December 2022 to see if any relationship was found between maternal nutrition and its consequences on children's allergy occurrence. We will focus only on food allergy and eczema outcomes in the offspring. Also, we will summarize what was found to be protective or nonprotective to better control the outcomes if applied in the future.

Rising prevalence of food allergies in Taiwan: An epidemiological study

BACKGROUND

Food allergies are becoming more prevalent globally. The purpose of this study was to investigate the epidemiology of food allergies in Taiwan.

METHODS

In 2017, a food allergy questionnaire was administered to 6-7-year-old children, 13-14-year-old adolescents, and their parents in Taipei. The results were compared to those from a previous survey conducted in 2004.

RESULTS

A total of 16,200 questionnaires were completed, revealing a rise in the prevalence of food allergies from 7.7% to 10.4% in the pediatric group and from 6.4% to 12.5% in the adult group. Peanut allergies also increased to 1.1%. Shrimp and crabs were the most common allergens, with urticaria being the most common symptom. Shortness of breath or wheezing occurred in 10% of individuals, while 2.1% experienced syncope or shock, and 0.1% were admitted to an intensive care unit. Personal history of allergic rhinitis and atopic dermatitis, as well as family histories of food allergies, were risk factors for food allergy in 6-7-year-old children. In the 13-14-year-old group, personal history of asthma, allergic rhinitis, or atopic dermatitis, recent use of acetaminophen, and living with dogs were risk factors. Females, personal histories of asthma, allergic rhinitis, atopic dermatitis, and moist and damp at home were risk factors in adults. Breastfeeding was a protective factor in 6-7-year-old children.

CONCLUSION

The increasing prevalence of food allergies, including peanut allergies, in Taiwan warrants attention from physicians to provide appropriate care and education to patients with food allergies. The protective effect of breastfeeding against food allergies shall be emphasized.

Frequency of food allergy in Europe: An updated systematic review and meta-analysis

Food allergy (FA) is increasingly reported in Europe, however, the latest prevalence estimates were based on studies published a decade ago. The present work provides the most updated estimates of the prevalence and trends of FA in Europe. Databases were searched for studies published between 2012 and 2021, added to studies published up to 2012. In total, 110 studies were included in this update. Most studies were graded as moderate risk of bias. Pooled lifetime and point prevalence of self-reported FA were 19.9% (95% CI 16.6-23.3) and 13.1% (95% CI 11.3-14.8), respectively. The point prevalence of sensitization based on specific IgE (slgE) was 16.6% (95% CI 12.3-20.8), skin prick test (SPT) 5.7% (95% CI 3.9-7.4), and positive food challenge 0.8% (95% CI 0.5-0.9). While lifetime prevalence of self-reported FA and food challenge positivity only slightly changed, the point prevalence of self-reported FA, sIgE and SPT positivity increased from previous estimates. This may reflect a real increase, increased awareness, increased number of foods assessed, or increased number of studies from countries with less data in the first review. Future studies require rigorous designs and implementation of standardized methodology in diagnosing FA, including use of double-blinded placebo-controlled food challenge to minimize potential biases.

English Version of Clinical Practice Guidelines for the Management of Atopic Dermatitis 2021

This is the English version of the Clinical Practice Guidelines for the Management of Atopic Dermatitis 2021. Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion. In Japan, from the perspective of evidence-based medicine, the current strategies for the treatment of AD consist of three primary measures: (i) use of topical corticosteroids, tacrolimus ointment, and delgocitinib ointment as the main treatment of the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling, and advice about daily life. In the present revised guidelines, descriptions of three new drugs, namely, dupilumab, delgocitinib, and baricitinib, have been added. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice.

Breastfeeding: Maternally Transferred Allergens in Breast Milk: Protective or Sensitizing?

According to a thorough literature search, the following allergen sources have been associated with allergy symptoms in the exclusively breastfed child: hen's egg, cow's milk, peanut, trout. Subsequently, several studies use the advantage of molecular allergology and investigate the potential transfer of single allergens into breastmilk. This is shown for caseins, whey proteins, gliadin, ovalbumin, ovomucoid, the peanut allergens Ara h 2 and Ara h 6, as well as the inhalant allergens Der p 1 and Blo t 5. It is still a matter of debate whether or not food allergens transferred via breastfeeding to the baby promote allergic sensitization or induce tolerance and via which mechanisms they may shift the immune response to the one or other side. Noteworthy, some breastfed children are described to be sensitized to foods before being exposed to solid foods, and this exposure may have occurred through breastmilk. In the light of these findings the investigation of food allergens transferred from the mother's diet into breastmilk and their impact on sensitization or allergy prevention remains a current topic in research. This review describes breastmilk in its composition and provides data on the identification of food allergens therein including human and mouse studies.

Maternal Influences and Intervention Strategies on the Development of Food Allergy in Offspring

Food allergies and other immune-mediated diseases have become serious health concerns amongst infants and children in developed and developing countries. The absence of available cures limits disease management to allergen avoidance and symptomatic treatments. Research has suggested that the presence of maternal food allergies may expose the offspring to genetic predisposition, making them more susceptible to allergen sensitization. The following review has focused on epidemiologic studies regarding maternal influences of proneness to develop food allergy in offspring. The search strategy was "food allergy OR maternal effects OR offspring OR prevention". A systematically search from PubMed/MEDLINE, Science Direct and Google Scholar was conducted. Specifically, it discussed the effects of maternal immunity, microbiota, breastfeeding, genotype and allergy exposure on the development of food allergy in offspring. In addition, several commonly utilized prenatal and postpartum strategies to reduce food allergy proneness were presented, including early diagnosis of high-risk infants and various dietary interventions.

Allergy to Peanuts imPacting Emotions And Life (APPEAL): The impact of peanut allergy on children, teenagers, adults and caregivers in the UK and Ireland

The Allergy to Peanuts imPacting Emotions And Life study (APPEAL) explored the psychosocial burden of living with self-reported peanut allergy experienced by children, teenagers, adults and caregivers in the UK and Ireland. A two-stage (quantitative survey and qualitative interview [APPEAL-1]), cross-sectional study of the psychosocial burden of peanut allergy (APPEAL-2) was conducted. Quantitative data were evaluated using descriptive statistics and qualitative data were analysed using MAXQDA software. A conceptual model specific to UK and Ireland was developed using the concepts identified during the analysis. A total of 284 adults in the UK and Ireland completed the APPEAL-1 survey and 42 individuals participated in APPEAL-2. Respondents reported that peanut allergy restricts their choices in various situations, especially with regard to choosing food when eating out (87% moderately or severely restricted), choosing where to eat (82%), special occasions (76%) and when buying food from a shop (71%). Fifty-two percent of survey participants and 40% of interview participants reported being bullied because of PA. Psychological impact of peanut allergy included feeling at least moderate levels of frustration (70%), uncertainty (79%), and stress (71%). The qualitative analysis identified three different types of coping strategies (daily monitoring or vigilance, communication and planning) and four main areas of individuals’ lives that are impacted by peanut allergy (social activities, relationships, emotions and work [adults and caregivers only]). The extent of the impact reported varied substantially between participants, with some reporting many negative consequences of living with peanut allergy and others feeling it has minimal impact on their health-related quality of life. This large survey and interview study highlight the psychosocial burden of peanut allergy for adults, teenagers, children and caregivers in the UK and Ireland. The analysis demonstrates the wide variation in level of impact of peanut allergy and the unmet need for those individuals who experience a substantial burden from living with peanut allergy.

Early-life predictors and risk factors of peanut allergy, and its association with asthma in later-life: Population-based birth cohort study

BACKGROUND

Understanding risk factors for peanut allergy (PA) is essential to develop effective preventive measures.

OBJECTIVE

To ascertain associates and predictors of PA, and the relationship between PA and asthma severity.

METHODS

In a population-based birth cohort, we investigated the association between objectively confirmed PA with early-life environmental exposures, filaggrin (FLG)-loss-of-function mutations and other atopic disease. We then examined the association of PA with longitudinal trajectories of sensitisation, wheeze and allergic comorbidities, which were previously derived using machine learning. Finally, we ascertained the relationship between PA and asthma severity.

RESULTS

PA was confirmed in 30/959 participants with evaluable data. In the multivariate analysis, eczema in infancy (OR=4.4, 95% CI 1.5-13.2, p=0.007), egg sensitisation at age 3 years (OR=9.7, 95% CI 3.3-29.9, p<0.001) and early-life cat ownership (OR=3.0, 95% CI 1.1-8.4, p=0.04) were independent associates of PA. In the stratified analysis among 700 participants with genetic information, in children with early-life eczema there was no difference in FLG mutations between children with and without PA (3/18 [16.7%] vs. 42/220 [19.1%], p=1.00). In contrast, among children without eczema, those with PA were almost 8-times more likely to have FLG mutations (2/6 [33.3%] vs. 27/456 [5.9%], p=0.049). We observed associations between PA and multiple allergic sensitisation profiles derived using machine learning, with ~60-fold increase in risk amongst individuals assigned to multiple early sensitisation. PA was significantly associated with persistent wheeze (but not other wheeze phenotypes), and with trajectories of atopic disease characterised by co-morbid persistent eczema and wheeze (but not with transient phenotypes). Children with PA were more likely to have asthma, but among asthmatics we found no evidence of an association between PA and asthma severity.

CONCLUSIONS

Peanut allergy is associated with multiple IgE-sensitisation and early-onset persistent eczema and wheeze. FLG loss-of-function mutations were associated with peanut allergy in children without eczema.

BSACI 2021 guideline for the management of egg allergy

This guideline advises on the management of patients with egg allergy. Most commonly egg allergy presents in infancy, with a prevalence of approximately 2% in children and 0.1% in adults. A clear clinical history will confirm the diagnosis in most cases. Investigation by measuring egg-specific IgE (by skin prick testing or specific IgE assay) is useful in moderate-severe cases or where there is diagnostic uncertainty. Following an acute allergic reaction, egg avoidance advice should be provided. Egg allergy usually resolves, and reintroduction can be achieved at home if reactions have been mild and there is no asthma. Patients with a history of severe reactions or asthma should have reintroduction guided by a specialist. All children with egg allergy should receive the MMR vaccine. Most adults and children with egg allergy can receive the influenza vaccine in primary care, unless they have had anaphylaxis to egg requiring intensive care support. Yellow Fever vaccines should only be considered in egg-allergic patients under the guidance of an allergy specialist. This guideline was prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) and is intended for allergists and others with a special interest in allergy. The recommendations are evidence based. Where evidence was lacking, consensus was reached by the panel of specialists on the committee. The document encompasses epidemiology, risk factors, diagnosis, treatment, prognosis and co-morbid associations.

White paper on peanut allergy - part 1: Epidemiology, burden of disease, health economic aspects

Peanuts are Leguminosae, commonly known as the legume or pea family, and peanut allergy is among the most common food allergies and the most common cause of fatal food reactions and anaphylaxis.

The prevalence of peanut allergy increased 3.5-fold over the past two decades reaching 1.4–2% in Europe and the United States. The reasons for this increase in prevalence are likely multifaceted. Sensitization via the skin appears to be associated with the development of peanut allergy and atopic eczema in infancy is associated with a high risk of developing peanut allergy.

Until recently, the only possible management strategy for peanut allergy was strict allergen avoidance and emergency treatment including adrenaline auto-injector in cases of accidental exposure and reaction.

This paper discusses the various factors that impact the risks of peanut allergy and the burden of self-management on peanut-allergic children and their caregivers.

From Allergen Molecules to Molecular Immunotherapy of Nut Allergy: A Hard Nut to Crack

Peanuts and tree nuts are two of the most common elicitors of immunoglobulin E (IgE)-mediated food allergy. Nut allergy is frequently associated with systemic reactions and can lead to potentially life-threatening respiratory and circulatory symptoms. Furthermore, nut allergy usually persists throughout life. Whether sensitized patients exhibit severe and life-threatening reactions (e.g., anaphylaxis), mild and/or local reactions (e.g., pollen-food allergy syndrome) or no relevant symptoms depends much on IgE recognition of digestion-resistant class I food allergens, IgE cross-reactivity of class II food allergens with respiratory allergens and clinically not relevant plant-derived carbohydrate epitopes, respectively. Accordingly, molecular allergy diagnosis based on the measurement of allergen-specific IgE levels to allergen molecules provides important information in addition to provocation testing in the diagnosis of food allergy. Molecular allergy diagnosis helps identifying the genuinely sensitizing nuts, it determines IgE sensitization to class I and II food allergen molecules and hence provides a basis for personalized forms of treatment such as precise prescription of diet and allergen-specific immunotherapy (AIT). Currently available forms of nut-specific AIT are based only on allergen extracts, have been mainly developed for peanut but not for other nuts and, unlike AIT for respiratory allergies which utilize often subcutaneous administration, are given preferentially by the oral route. Here we review prevalence of allergy to peanut and tree nuts in different populations of the world, summarize knowledge regarding the involved nut allergen molecules and current AIT approaches for nut allergy. We argue that nut-specific AIT may benefit from molecular subcutaneous AIT (SCIT) approaches but identify also possible hurdles for such an approach and explain why molecular SCIT may be a hard nut to crack.

The influence of cultural attitudes to nut exposure on reported nut allergy: A pilot cross sectional study

Food allergies in children have become a common management and diagnostic concern and have a significant influence on general health-related quality of life. We investigated the prevalence of reported nut allergy between populations with different cultural attitudes to nuts during pregnancy and infancy. We conducted a survey to investigate the relationship between cultural differences in the consumption of nuts during pregnancy, breastfeeding and exposure to nuts in early childhood against the reported prevalence of nut allergy between three populations: Libyan, UK Libyan and a general UK population. The survey was administered to a representative sample of UK and Libyan parents with children aged between 3 and 16 years who were asked to report prevalence of nut allergy and to describe the factors that might affect this such as cultural behaviours and diet. A total of 1,123 parents responded. Nut allergy was defined as an allergic reaction that required medical treatment. The reported rates of nut allergy showed a significant difference in nut allergy between the Libyan populations and the general UK population with an increased odds ratio of nut allergy of ~10 when comparing the Native Libyan population to the UK population. The UK Libyan population reported the same low rate of allergic reactions as the Libyan population which were both significantly lower than the UK population (p < .0001). The Libyan populations showed significant differences from the UK population in exposure to nuts during pregnancy, breastfeeding and early infancy. The development of peanut and almond allergy through tolerance induction could be prevented by frequent and early ingestion of a moderate quantity of nuts during infancy and by maternal ingestion during pregnancy or lactation.

Clinical practice guidelines for the management of atopic dermatitis 2018

Atopic dermatitis (AD) is a disease characterized by relapsing eczema with pruritus as a primary lesion. The current strategies to treat AD in Japan from the perspective of evidence-based medicine consist of three primary measures: (i) the use of topical corticosteroids and tacrolimus ointment as the main treatment for the inflammation; (ii) topical application of emollients to treat the cutaneous barrier dysfunction; and (iii) avoidance of apparent exacerbating factors, psychological counseling and advice about daily life. The guidelines present recommendations to review clinical research articles, evaluate the balance between the advantages and disadvantages of medical activities, and optimize medical activity-related patient outcomes with respect to several important points requiring decision-making in clinical practice.

Timing of Introduction, Sensitization, and Allergy to Highly Allergenic Foods at Age 3 Years in a General-Population Canadian Cohort

BACKGROUND

Early dietary introduction of highly allergenic foods has been associated with decreased risk of food allergy in high-risk infants.

OBJECTIVE

Early introduction of highly allergenic foods for lower risk infants was examined using Canadian Healthy Infant Longitudinal Development (CHILD) Study data.

METHODS

CHILD participants were recruited from the general population before birth. Every 6 months, caregivers reported food introduction and allergic reactions. At ages 1 and 3 years, sensitization to peanut, egg, and cow's milk was measured by skin prick testing (SPT) and atopic dermatitis diagnosed at clinical visits. Multivariable logistic regression was used to examine associations between timing of introduction to peanut, egg, and cow's milk and the presence at 3 years of sensitization (positive SPT) and probable clinical IgE-mediated allergy (sensitization with no current consumption and convincing history of allergic reaction to the specific food).

RESULTS

Among 2669 CHILD participants at age 3 years, 101 (3.80%) showed sensitization to peanut, 59 (2.21%) to egg, and 30 (1.12%) to cow's milk; 46 (1.78%) showed probable clinical IgE-mediated allergy to peanut, 4 (0.16%) to egg, and 2 (0.08%) to cow's milk. Infants introduced to peanut after 12 months had increased odds of sensitization (odds ratio [OR]: 2.38, 95% confidence interval [CI]: 1.39-4.07) and probable clinical allergy (OR: 4.04, 95% CI: 1.66-9.85) to peanut at 3 years. Associations persisted after exclusion of high-risk infants with moderate-to-severe atopic dermatitis in the first year/egg sensitization at 1 year.

CONCLUSIONS

General-population infants introduced to peanut after age 12 months were more likely to have sensitization and probable clinical allergy to peanut at 3 years.

Influences of Maternal Factors Over Offspring Allergies and the Application for Food Allergy

The prevalence of food allergy has been steadily rising worldwide with the highest incidence noted among younger children, and increasingly recognized as a growing public concern. The first known ingestion of foods often causes allergic reaction, suggesting that sensitization of offspring with food allergens may occur during pregnancy and/or through breastfeeding. This creates a milieu that shapes the neonatal immune responses to these allergens. However, the effects of maternal allergen exposure and maternal sensitization with allergens on development of allergies in offspring remain controversial. This review discusses recent advances from human data in our understanding of how maternal factors, namely, food allergens, allergen-specific immunoglobulins, cytokines, genetics, and environmental factors transferred during pregnancy or breastfeeding influence offspring allergies and how such effects may be applicable to food allergy. Based on information obtained from mouse models of asthma and food allergy, the review also dissects the mechanisms by which maternal factors, including the impact of immune complexes, transforming growth factor-β, vitamin A, and regulatory T-cell responses, contribute to the induction of neonatal tolerance vs. development of allergic responses to maternally transferred allergens.

Food immunotherapy for children with food allergies: state of the art and science

PURPOSE OF REVIEW

This review examines the current literature and provides insight into the role of food immunotherapy in the management of food-allergic children. Key food immunotherapy trials, benefits, and risks of the intervention, as well as areas requiring further study are all discussed.

RECENT FINDINGS

Research studies have reported encouraging results regarding the efficacy of food immunotherapy in desensitizing food-allergic patients with an acceptable safety profile and a documented improvement in quality of life. The role of biologics and long-term effects of food immunotherapy are still under investigation.

SUMMARY

The burden of food allergy is significant, multifaceted, and well documented. Food immunotherapy is a novel treatment option and an exciting area of research that has seen tremendous progress over the last decade, presenting encouraging results for the treatment of children with food allergies.

BSACI guideline for the diagnosis and management of peanut and tree nut allergy

Peanut nut and tree nut allergy are characterised by IgE mediated reactions to nut proteins. Nut allergy is a global disease. Limited epidemiological data suggest varying prevalence in different geographical areas. Primary nut allergy affects over 2% of children and 0.5% of adults in the UK. Infants with severe eczema and/or egg allergy have a higher risk of peanut allergy. Primary nut allergy presents most commonly in the first five years of life, often after the first known ingestion with typical rapid onset IgE-mediated symptoms. The clinical diagnosis of primary nut allergy can be made by the combination of a typical clinical presentation and evidence of nut specifc IgE shown by a positive skin prick test (SPT) or specific IgE (sIgE) test. Pollen food syndrome is a distinct disorder, usually mild, with oral/pharyngeal symptoms, in the context of hay fever or pollen sensitisation, which can be triggered by nuts. It can usually be distinguish clinically from primary nut allergy. The magnitude of a SPT or sIgE relates to the probability of clinical allergy, but does not relate to clinical severity. SPT of ≥ 8 mm or sIgE ≥ 15 KU/L to peanut is highly predictive of clinical allergy. Cut off values are not available for tree nuts. Test results must be interpreted in the context of the clinical history. Diagnostic food challenges are usually not necessary but may be used to confirm or refute a conflicting history and test result. As nut allergy is likely to be a long-lived disease, nut avoidance advice is the cornerstone of management. Patients should be provided with a comprehensive management plan including avoidance advice, patient specific emergency medication and an emergency treatment plan and training in administration of emergency medication. Regular re-training is required.

Primary Prevention of Food Allergy: Translating Evidence from Clinical Trials to Population-Based Recommendations

Given the prevalence and impact of childhood food allergy, there is increasing interest in interventions targeting disease prevention. Although interventions such as early introduction of dietary peanut have demonstrated efficacy in a small number of well-conducted randomized clinical trials, evidence for broader effectiveness and successful implementation at a population level is still lacking, although epidemiological data suggest that such strategies are likely to be successful, at least for peanut. In this commentary, we explore the issues of translating evidence of efficacy studies (performed under optimal conditions) to make policy recommendations at a population level, and highlight potential benefits, harms, and unintended consequences of making population-based recommendations on the basis of randomized controlled trials. We discuss the complexity and barriers to effective primary and secondary prevention intervention implementation in resource-poor settings.

Fetal Phagocytes Take up Allergens to Initiate T-Helper Cell Type 2 Immunity and Facilitate Allergic Airway Responses

RATIONALE

Actively acquired tolerance occurs when foreign antigens come into contact with the immature fetal immune system.

OBJECTIVES

Armed with the knowledge of actively acquired tolerance, we attempted to prenatally abolish or diminish allergic responses.

METHODS

In utero injection of adjuvant-free ovalbumin (OVA) was conducted in Gestational Day 14 FVB/N mouse fetuses. Postnatally, mice were evaluated for their resistance to intraperitoneal OVA sensitization and oral or aerosolized OVA challenge, and then they were examined for humoral and cellular immunological profiles, airway hyperresponsiveness to bronchospastic stimuli, and lung histology. Fluorescent conjugates of OVA were used for further studies of mechanisms.

MEASUREMENTS AND MAIN RESULTS

This presumed tolerogenic action turned out to be a sensitization process with the development of anaphylaxis or heightened recall, T-helper cell type 2-skewed responses to postnatal encounter with OVA. Further postnatal aerosolized OVA stress triggered allergic lungs with functional and structural alterations of airways. The unintended consequence resulted from macrophage-like fetal phagocytes that took up OVA and differentiated toward dendritic cells. These fetal dendritic cell progenitors attenuated proteolysis of endocytosed OVA for delayed presentation in postnatal life. This specialty of fetal phagocytes effectively retains the memory of antigens internalized early before full development of the immune system, leading to an event of in utero sensitization.

CONCLUSIONS

Our results have mechanical implications for prenatal imprinting of atopy and shed light on the importance of fetal phagocytes in shaping the developing immune system and initiating allergic airway diseases.

Impact of peanut consumption in the LEAP Study: Feasibility, growth, and nutrition

BACKGROUND

Early introduction of peanut is an effective strategy to prevent peanut allergy in high-risk infants; however, feasibility and effects on growth and nutritional intake are unknown.

OBJECTIVE

We sought to evaluate the feasibility of introducing peanut in infancy and explore effects on growth and nutritional intake up to age 60 months.

METHODS

In the Learning Early About Peanut Allergy trial, 640 atopic infants aged 4 to 11 months were randomly assigned to consume (6 g peanut protein per week) or avoid peanut until age 60 months. Peanut consumption and early feeding practices were assessed by questionnaire. Dietary intake was evaluated with prospective food diaries. Anthropometric measurements were taken at all study visits.

RESULTS

Peanut was successfully introduced and consumed until 60 months, with median peanut protein intake of 7.5 g/wk (interquartile range, 6.0-9.0 g/wk) in the consumption group compared with 0 g in the avoidance group. Introduction of peanut in breast-feeding infants did not affect the duration of breast-feeding. There were no differences in anthropometric measurements or energy intakes between groups at any visits. Regular peanut consumption led to differences in dietary intakes. Consumers had higher intakes of fat and avoiders had higher carbohydrate intakes; differences were greatest at the upper quartiles of peanut consumption. Protein intakes remained consistent between groups.

CONCLUSIONS

Introduction of peanut proved feasible in infants at high risk of peanut allergy and did not affect the duration of breast-feeding nor impact negatively on growth or nutrition. Energy balance was achieved in both groups through variations in intakes from fat and carbohydrate while protein homeostasis was maintained.

Simulation-based sample-sizing and power calculations in logistic regression with partial prior information

There have been many approximations developed for sample sizing of a logistic regression model with a single normally-distributed stimulus. Despite this, it has been recognised that there is no consensus as to the best method. In pharmaceutical drug development, simulation provides a powerful tool to characterise the operating characteristics of complex adaptive designs and is an ideal method for determining the sample size for such a problem. In this paper, we address some issues associated with applying simulation to determine the sample size for a given power in the context of logistic regression. These include efficient methods for evaluating the convolution of a logistic function and a normal density and an efficient heuristic approach to searching for the appropriate sample size. We illustrate our approach with three case studies. Copyright © 2016 John Wiley & Sons, Ltd.

Prevalence of sensitization to food allergens and challenge proven food allergy in patients visiting allergy centers in Rawalpindi and Islamabad, Pakistan

In this study, we estimated the prevalence of food allergy in the adult allergic patients of Rawalpindi and Islamabad , Pakistan, based on self-report, skin prick test (SPT) and oral food challenge test (OFC). SPT was used for the estimation of sensitization to wheat, egg, milk, beef, chicken, mutton, fish, corn, lentils, rice, soya, peanut and banana. Among 689 patients, 39.19 % showed sensitivity to one or more foods, where, sensitization to wheat (156; 22.6 %) was highest, followed by egg (148; 21.48 %) and milk (138; 20.03 %). Sensitization to various proteins ranged between 15.53–15.97 %, while lentils, corn, rice, soya and peanut sensitization was 15.4, 16, 12.5, 12 and 11.5 % respectively. Only 7.1 % patients were SPT positive for banana allergen. SPT was performed in patients with self-reported food allergy (341/689) and also with no self-reported history of food allergy (348/689). SPT results were positive in 69.8 % of the self-report group, whereas, in the patients with no self-reported food allergy 9.2 % were found sensitized to one or more tested food allergens. 101 patients were recruited for OFC, 61 % of these were confirmed of food allergy. The prevalence of food allergy in the study population was 9 %. Food specific OFC results show that wheat allergy is affecting 1.6 % (95 % CI 0.9–2.84 %) of the total allergy patients, followed by egg allergy 1.31 % (95 % CI 0.70–2.47 %). Furthermore, corn allergy, rice allergy and peanut allergy were 1.02, 0.87 and 0.73 %, respectively. In conclusion, wheat allergy is the most prevalent, followed by egg, chicken, beef and fish allergy, respectively.

The accuracy of dietary recall of infant feeding and food allergen data

BACKGROUND

Research investigating the association of infant dietary factors with later health outcomes often relies on maternal recall. It is unclear what the effect of recall bias is on the accuracy of the information obtained. The present study aimed to determine the extent of recall bias on the accuracy of infant feeding and food allergen data collected 10 years later.

METHODS

Mothers were recruited from a prospective birth cohort from the Isle of Wight. When their child was 10 years of age (2011/2012), mothers were requested to complete a retrospective infant feeding questionnaire asking the same questions as those solicited in 2001/2002.

RESULTS

In total, 125 mothers participated. There was substantial agreement for recollection of any breastfeeding (κ = 0.79) and the duration of breastfeeding from 10 years earlier (r = 0.84). Some 94% of mothers recalled accurately that their child had received formula milk. The exact age at which formula milk was first given was reliably answered (r = 0.63). The brand of formula milk was poorly recalled. Recall of age of introduction of solid food was not reliable (r = 0.16). The age of introduction of peanuts was the only food allergen that was recalled accurately (86%).

CONCLUSIONS

The present study highlights the importance of maternal recall bias of infant feeding practices over 10 years. Recall related to breastfeeding and formula feeding were reliable, whereas recalls related to age of introduction of solid or allergenic foods, apart from peanut, were not. Caution should be applied when interpreting studies relying on dietary recall.

Dietary management of peanut and tree nut allergy: what exactly should patients avoid?

Peanut and tree nut allergies are the commonest cause of life-threatening food-allergic reactions and significantly affect quality of life in children and their families. Dietary nut avoidance and provision of emergency medication is currently the mainstay of treatment. Nut avoidance has consequences on both quality of life and nutrition. We review the terminology that may cause confusion and lead to unnecessary dietary restrictions. In peanut or tree nut-allergic children, introduction of specific nuts to which the child is not allergic may improve quality of life and should be considered in patients with multiple foods allergies, vegan or ethnic-specific diets, in whom nuts are an important source of protein. Nut-allergic consumers do not just need to avoid foods containing nuts as an ingredient, but also contend with pre-packed foods which frequently have precautionary allergen labelling (PAL) referring to possible nut contamination. Although the published rate of peanut contamination in 'snack' foods with PAL (see Box ) ranges from 0.9-32.4%, peanut contamination in non-snack items with PAL is far less common. We propose that in some peanut-allergic patients (depending on history of reactivity to trace levels of peanut, reaction severity, other medical conditions, willingness to always carry adrenaline, etc.), consideration may be given to allow the consumption of non-snack foods containing PAL following discussion with the patient's (and their family's) specialist. More work is needed to provide consumers with clearer information on the risk of potential nut contamination in pre-packed food. We also draw attention to the change in legislation in December 2014 that require mandatory disclosure of allergens in non-pre-packed foods.

Sensitization pattern to inhalant and food allergens in symptomatic children at first evaluation

Background

Data on specific IgE sensitization prevalence in children with allergy-like symptoms seen in the primary care setting are rare. Early diagnosis of allergic diseases is important to prevent clinical manifestations, exacerbations or expansion of allergic diseases to other organ systems. The present study aims to assess the usefulness of early serological diagnosis in children with common allergic symptoms.

Methods

532 children (<15 years of age), with at least one of ten allergy-like symptoms, from 21 primary care centers in two geographic areas of Italy and Spain were included in the study. Patients were tested with, either Phadiatop® Infant (0–5 years of age) or Phadiatop® and food mix (fx5e) (>5 years of age) to discriminate atopic from non-atopic subjects. A blood sample of atopic subjects was taken for additional 6–26 specific IgE antibody determinations from a predefined panel using the ImmunoCAP^® System.

Results

267 children (50.2 %) were positive in the initial test and were classified as atopic. 14 % were mono-sensitized, 37 % were sensitized to 2–3 allergens and 49 % to more than 3 allergens. The average number of symptoms in the atopic group was 3.3 vs 2.8 in the non-atopic group. The prevalence of sensitization to single allergens was highest for grass and ragweed pollen and house-dust mites (19–28 %). Sensitization to tree allergens was highest for olive tree (16.5 %). Cow’s milk and egg white were the most sensitizing foods (~15 %). Food allergen sensitization predominated in younger children (OR = 2.8) whereas the inverse occurred with inhalant allergens (OR = 2.5 to 5.6). A significant positive correlation between patient age and the number of sensitizations was found.

Conclusions

Specific IgE sensitization in children with allergy-like symptoms is common. Multiple sensitization is predominating. Number of clinical symptoms was higher in the atopic group compared to the non-atopic without a correlation with the number of positive allergens. Age seems to play a crucial role in the development of sensitization with a significant positive correlation between patient age and the number of sensitizations.

Taking the leap earlier: the timing of tolerance

PURPOSE OF REVIEW

The paradigm for the primary prevention of peanut allergy was, until recently, strict avoidance of peanut during pregnancy, infancy, and early childhood. However, in countries that had these dietary guidelines, the prevalence of peanut allergy greatly increased in contrast to low prevalence rates of peanut allergy in countries where infant diets included peanut at an early age, suggesting the hypothesis that early introduction of peanut is superior to delayed introduction of peanut as a strategy for the primary prevention of food allergy. This review examines recent high-quality studies that support this hypothesis.

RECENT FINDINGS

Publication of the Learning Early about Allergy to Peanut interventional trial showed that 17% of children avoiding peanut until 5 years of age developed peanut allergy compared with 3% of children who started eating peanut at ages of 4-11 months. Two birth cohort studies demonstrated that high maternal consumption of peanut during the pregnancy period reduced the risk of peanut allergy in offspring by 50-75%.

SUMMARY

Recent studies indicate that early introduction of peanut enhances the development of tolerance to peanut, reducing the risk of childhood peanut allergy.

Recent advances in immunotherapy and vaccine development for peanut allergy

Peanut allergy is a common problem and can be the cause of severe, life-threatening allergic reactions. It rarely resolves, with the majority of patients carrying the disease onto adulthood. Peanut allergy poses a significant burden on the quality of life of sufferers and their families, which results mainly from the fear of accidental peanut ingestion, but is also due to dietary and social restrictions. Current standard management involves avoidance, patient education and provision of emergency medication, for use in allergic reactions, when they occur. Efforts have been made to develop a vaccine for peanut allergy. Recent developments have also highlighted the use of immunotherapy, which has shown promise as an active form of treatment and may present a disease-modifying therapy for peanut allergy. So far, results, especially from oral immunotherapy studies, have shown good efficacy in achieving desensitization to peanut with a good safety profile. However, the capacity to induce long-term tolerance has not been demonstrated conclusively yet and larger, phase III studies are required to further investigate safety and efficacy of this intervention. Peanut immunotherapy is not currently recommended for routine clinical use or outside specialist allergy units.

Supplementation of Mice with Specific Nondigestible Oligosaccharides during Pregnancy or Lactation Leads to Diminished Sensitization and Allergy in the Female Offspring

BACKGROUND

The maternal environment and early life exposure affect immune development in offspring.

OBJECTIVE

We investigated whether development of food allergy in offspring is affected by supplementing pregnant or lactating sensitized or nonsensitized mice with a mixture of nondigestible oligosaccharides.

METHODS

Dams were sensitized intragastrically with ovalbumin before mating, with use of cholera toxin (CT) as an adjuvant. Nonsensitized dams received CT only. Dams were fed a control diet or a diet supplemented with short-chain galacto oligosaccharides (scGOSs), long-chain fructo oligosaccharides (lcFOSs), and pectin-derived acidic oligosaccharides (pAOSs) in a ratio of 9:1:2 at a dose of 2% during pregnancy or lactation, resulting in 7 experimental groups. After weaning, offspring were fed a control diet and ovalbumin-CT sensitized. Acute allergic skin responses (ASRs), shock symptoms, body temperature, and specific plasma immunoglobulins were measured upon intradermal ovalbumin challenge. Th2/Th1- and regulatory T cells were analyzed with use of quantitative polymerase chain reaction and flow cytometric analysis in spleen, mesenteric lymph nodes, and blood.

RESULTS

Supplementing sensitized pregnant or lactating dams with scGOS/lcFOS/pAOS resulted in lower ASRs in the offspring [offspring of sensitized female mice fed experimental diet during pregnancy (S-Preg): 48 ± 2.1 μm; offspring of sensitized female mice fed experimental diet during lactation (S-Lact): 60 ± 6.2 μm] compared with the sensitized control group (119 ± 13.9 μm). In the S-Lact group, this coincided with an absence of shock symptoms compared with the offspring of sensitized female mice fed control food during pregnancy and lactation (S-Con) and S-Preg groups, and lower ovalbumin-IgG1 [S-Con: 3.8 ± 0.1 arbitrary units (AUs); S-Preg: 3.3 ± 0.1 AUs; S-Lact: 2.4 ± 0.1 AUs] and higher ovalbumin-IgG2a concentrations (S-Con: 1.1 ± 0.1 AUs; S-Preg: 0.8 ± 0.1 AUs; S-Lact: 2.0 ± 0.1 AUs). Supplementing nonsensitized pregnant or lactating dams with scGOS/lcFOS/pAOS resulted in lower plasma ovalbumin-IgE [offspring of nonsensitized female mice fed experimental diet during pregnancy (NS-Preg): 1.6 ± 0.4 AUs; offspring of nonsensitized female mice fed experimental diet during lactation (NS-Lact): 0.3 ± 0.1 AUs vs. offspring of nonsensitized female mice fed control food during pregnancy and lactation (NS-Con): 3.1 ± 0.6 AUs] and ovalbumin-IgG1 (NS-Lact: 2.3 ± 0.3 AUs vs. NS-Con: 3.4 ± 0.3 AUs) concentrations in offspring. Ovalbumin-IgG2a plasma concentrations were higher in offspring of scGOS/lcFOS/pAOS-supplemented dams (NS-Preg: 1.1 ± 0.1 AUs; NS-Lact: 1.1 ± 0.1 AUs) than in those of unsupplemented, nonsensitized controls (0.4 ± 0.0 AUs).

CONCLUSIONS

These data show impaired sensitization in offspring of scGOS/lcFOS/pAOS-supplemented mice. A number of the analyzed variables are differentially affected by whether supplementation occurs during pregnancy or lactation, and the outcome of dietary supplementation is affected by whether the mother has been sensitized to ovalbumin and CT.

The management of peanut allergy

Peanut allergy is common and can be a cause of severe, life-threatening reactions. It is rarely outgrown like other food allergies such as egg and milk. Measures aiming to reduce its prevalence via maternal avoidance during pregnancy and lactation, or delayed introduction into the diet, have failed to show any benefit. Peanut allergy has a significant effect on the quality of life of sufferers and their families due to dietary and social restrictions, but mainly stemming from fear of accidental peanut ingestion. The current management consists of strict avoidance, education and provision of emergency medication. Families find avoidance challenging as peanut is hidden in various food products. Despite the fact that food labelling has improved, with a legal obligation to declare certain food allergens (including nuts) in prepacked products, it still causes confusion and does not extend to cross-contamination. In an effort to address issues of safety at school, a lot of work has been undertaken to better care for peanut-allergic children in that environment. This includes training of school staff on how to recognise and treat allergic reactions promptly. Recent developments in the management of peanut allergy, such as immunotherapy, have shown some promise as an active form of treatment, but larger studies are required to further investigate safety and efficacy.

Peanut immunotherapy

Peanut allergy is common and can be a cause of severe, life-threatening reactions. It is rarely outgrown like other food allergies, such as egg and milk. Peanut allergy has a significant effect on the quality of life of sufferers and their families, due to dietary and social restrictions, but mainly stemming from fear of accidental peanut ingestion. The current management consists of strict avoidance, education and provision of emergency medication, but a disease- modifying therapy is needed for peanut allergy. Recent developments involve the use of immunotherapy, which has shown promise as an active form of treatment. Various routes of administration are being investigated, including subcutaneous, oral, sublingual and epicutaneous routes. Other forms of treatment, such as the use of vaccines and anti-IgE molecules, are also under investigation. So far, results from immunotherapy studies have shown good efficacy in achieving desensitisation to peanut with a good safety profile. However, the issue of long-term tolerance has not been fully addressed yet and larger, phase III studies are required to further investigate safety and efficacy. An assessment of cost/benefit ratio is also required prior to implementing this form of treatment. The use of immunotherapy for peanut allergy is not currently recommended for routine clinical use and should not be attempted outside specialist allergy units.

Dietary exposures and allergy prevention in high-risk infants: a joint position statement of the Canadian Society of Allergy and Clinical Immunology and the Canadian Paediatric Society

Allergic conditions in children are a prevalent health concern in Canada. The burden of disease and the societal costs of proper diagnosis and management are considerable, making the primary prevention of allergic conditions a desirable health care objective. This position statement reviews current evidence on dietary exposures and allergy prevention in infants at high risk of developing allergic conditions. It revisits previous dietary recommendations for pregnancy, breastfeeding and formula-feeding, and provides an approach for introducing solid foods to high-risk infants. While there is no evidence that delaying the introduction of any specific food beyond six months of age helps to prevent allergy, the protective effect of early introduction of potentially allergenic foods (at four to six months) remains under investigation. Recent research appears to suggest that regularly ingesting a new, potentially allergenic food may be as important as when that food is first introduced. This article has already been published (Paediatr Child Health. 2013 Dec;18(10):545–54), and is being re-published with permission from the original publisher, the Canadian Paediatric Society.

Molecular sIgE profile in infants and young children with peanut sensitization and eczema

Background:

Many children develop a sensitization to peanut in early infancy, even before peanut is introduced in their diet. Sensitization is particularly common in young children with eczema. There have been scant data available to date on the sensitization pattern for specific peanut allergens in this patient group. The aim of this study was to investigate the allergen profile of infants and young children with peanut sensitization and eczema.

Methods:

Sera from 53 children aged ≤ 20 months with eczema and sensitization to peanut but who had not yet consumed products containing peanuts were included in the analysis. Sera were analyzed using microarray immunoassay (ImmunoCAP ISAC).

Results:

In total, 63 % of peanut-sensitized children showed specific immunoglobulin E (sIgE) against at least one peanut allergen on the microarray. Specific IgE to the 7S globulin Ara h 1 was detected in 40 % of the children, to the 2S albumin Ara h 2 in 30 % and to the 11S globulin Ara h 3 in 23 %. Only one child had sIgE to Arah 8, the homologoue of Bet-v-1. Data on clinical relevance were available for 24 of 53 children: 14 of 24 patients had objective allergic reactions to peanut, while 10 children were peanut-tolerant. The seed storage protein Ara h 2 was not detected on microarray in 43 % (6 of 14) of children with peanut allergy. Two of these six children were mono-sensitized to Ara h 1 and two to Ara h 3, while in three children none of these seed storage proteins was detected.

Discussion:

It could be shown that infants and young children with eczema and sensitization to peanut recognize predominantly seed storage proteins from peanut, even before the introduction of peanut into their diet. Sensitization to pollen-related food allergens seems to be rare at this age. At this age not only Ara h 2, but also Ara h 1 seems to be related to clinical relevance.

Prevalence of common food allergies in Europe: a systematic review and meta-analysis

Allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish constitutes the majority of food allergy reactions, but reliable estimates of their prevalence are lacking. This systematic review aimed to provide up-to-date estimates of their prevalence in Europe.Studies published in Europe from January 1, 2000, to September 30, 2012, were identified from searches of four electronic databases. Two independent reviewers appraised the studies and extracted the estimates of interest. Data were pooled using random-effects meta-analyses. Fifty studies were included in a narrative synthesis and 42 studies in the meta-analyses. Although there were significant heterogeneity between the studies, the overall pooled estimates for all age groups of self-reported lifetime prevalence of allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish were 6.0% (95% confidence interval: 5.7-6.4), 2.5% (2.3-2.7), 3.6% (3.0-4.2), 0.4% (0.3-0.6), 1.3% (1.2-1.5), 2.2% (1.8-2.5), and 1.3% (0.9-1.7), respectively. The prevalence of food-challenge-defined allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish was 0.6% (0.5-0.8), 0.2% (0.2-0.3), 0.1% (0.01-0.2), 0.3% (0.1-0.4), 0.2% (0.2-0.3), 0.5% (0.08-0.8), 0.1% (0.02-0.2), and 0.1% (0.06-0.3), respectively. Allergy to cow's milk and egg was more common among younger children, while allergy to peanut, tree nuts, fish, and shellfish was more common among the older ones. There were insufficient data to compare the estimates of soy and wheat allergy between the age groups. Allergy to most foods, except soy and peanut, appeared to be more common in Northern Europe. In summary, the lifetime self-reported prevalence of allergy to common foods in Europe ranged from 0.1 to 6.0%. The heterogeneity between studies was high, and participation rates varied across studies reaching as low as <20% in some studies. Standardizing the methods of assessment of food allergies and initiating strategies to increase participation will advance this evidence base.

Optimal timing for solids introduction - why are the guidelines always changing?

There have been dramatic changes in timing of first exposure to solid foods for children over the last 40 years, ranging from exposure prior to 4 months of age for most infants in the 1960s, to guidelines recommending delaying solids until after 6 months of age introduced in the 1990s. Infant diet, specifically age of weaning and age at introduction of allergenic foods, has long been thought to play a role food allergy. However, controversy surrounding the relationship between timing of introduction of foods and development of food allergy has lead to a plethora of inconsistent infant feeding guidelines both between and within countries. The aims of this article were to discuss the history of changing guidelines for optimal timing of introduction of solids in general and allergenic solids in particular and the evidence (or lack thereof) underpinning recommendations at each of these time-points. We present the current clinical equipoise with regards to recently revised guidelines published almost simultaneously in the UK, US and Australia and argue that guideline modification about timing of introduction (both for high risk infants but also for the general population) will require careful review of emerging literature to provide a true evidence base to inform public health practice such as infant feeding guidelines.

Dietary exposures and allergy prevention in high-risk infants: A joint statement with the Canadian Society of Allergy and Clinical Immunology

Allergic conditions in children are a prevalent health concern in Canada. The burden of disease and the societal costs of proper diagnosis and management are considerable, making the primary prevention of allergic conditions a desirable health care objective. This position statement reviews current evidence on dietary exposures and allergy prevention in infants at high risk for developing allergic conditions. It revisits previous dietary recommendations for pregnancy, breastfeeding and formula feeding, and provides an approach for introducing solid foods to high-risk infants. While there is no evidence that delaying the introduction of any specific food beyond six months of age helps to prevent allergy, the protective effect of early introduction of potentially allergenic foods (at four to six months of age) remains under investigation. Recent research appears to suggest that regularly ingesting a new, potentially allergenic food may be as important as when that food is first introduced.