Association Between Earlier Introduction of Peanut and Prevalence of Peanut Allergy in Infants in Australia

Regular consumption following early introduction of allergenic foods and aggressive treatment of eczema are necessary for preventing the development of food allergy in children

PURPOSE OF REVIEW

Over the past two decades, food allergy prevention strategies have shifted from 'delayed introduction' to 'no delayed introduction' to 'early introduction' of allergenic foods. This article reviews important research in this field published in the early 2020s to support future strategies for food allergy prevention.

RECENT FINDINGS

Recent randomized controlled trials (RCTs), systematic reviews, meta-analyses, and real-world studies have reported that early allergenic food introduction, especially peanut and egg, are effective for preventing food allergies. However, there are also reports that food-induced anaphylaxis admission rates in infants are increasing.

SUMMARY

Early allergenic food introduction by itself is not sufficient to prevent the development of food allergies. Recent RCTs (SPADE study and COMEET study) have demonstrated that continued regular cow's milk consumption after early introduction is important for preventing the onset of cow's milk allergy. Furthermore, an RCT (PACI study) reported that early and aggressive anti-inflammatory topical therapy for eczema can contribute to the prevention of egg allergy by suppressing percutaneous sensitization. Food allergies may be prevented through a combination of early food introduction, regular consumption, and active eczema treatment. Further research is needed to develop well tolerated, effective, and practical strategies to prevent food allergies.

Maternal and Infant Dietary Patterns Are Not Related to Food Allergy Risk in Singapore Children: GUSTO Cohort Study

BACKGROUND

We previously reported that delayed allergenic food introduction in infancy did not increase food allergy risk until age 4 y within our prospective cohort. However, it remains unclear whether other aspects of maternal or infant diet play roles in the development of childhood food allergy.

OBJECTIVES

We examined the relationship between maternal pregnancy and infant dietary patterns and the development of food allergies until age 8 y.

METHODS

Among 1152 Singapore Growing Up in Singapore Towards healthy Outcomes study mother-infant dyads, the infant's diet was ascertained using food frequency questionnaires at 18 mo. Maternal dietary patterns during pregnancy were derived from 24-h diet recalls. Food allergy was determined through interviewer-administered questionnaires at regular time points from infancy to age 8 y and defined as a positive history of allergic reactions, alongside skin prick tests at 18 mo, 3, 5, and 8 y.

RESULTS

Food allergy prevalence was 2.5% (22/883) at 12 mo and generally decreased over time by 8 y (1.9%; 14/736). Higher maternal dietary quality was associated with increased risk of food allergy (P ≤ 0.016); however, odds ratios were modest. Offspring food allergy risk ≤8 y showed no associations with measures of infant diet including timing of solids/food introduction (adjusted odds ratio [aOR]: 0.90; 95% confidence interval [CI]: 0.42, 1.92), infant's diet quality (aOR: 0.93; 95% CI: 0.88, 0.99) or diet diversity (aOR: 0.84; 95% CI: 0.6, 1.19). Most infants (89%) were first introduced to cow milk protein within the first month of life, while egg and peanut introduction were delayed (58.3% introduced by mean age 8.8 mo and 59.8% by mean age 18.1 mo, respectively).

CONCLUSIONS

Apart from maternal diet quality showing a modest association, infant's allergenic food introduction, diet quality, and dietary diversity were not associated with food allergy development in this Asian pediatric population. Interventional studies are needed to evaluate the efficacy of these approaches to food allergy prevention across different populations.

Skin-centered strategies in food allergy prevention

While the early introduction of food allergens in the infant diet has been shown to be effective at preventing the development of food allergy (FA), its implementation in real life has been associated with various challenges. Interventions aimed at correcting skin barrier dysfunction have been explored in recent decades as a distinct or complementary mean to prevent allergic sensitization through the skin and subsequent development of FA. Studies assessing the application of emollient from birth have yielded conflicting results, and meta-analyses have demonstrated either no effect or only a slight positive effect on FA prevention. However, a careful review of the clinical trials reveals that different emollients were used, which may have explained some of the discrepancies between study results. Emollient application protocols also varied widely between studies. While firm conclusions cannot be drawn with regard to their overall efficacy at preventing FA, the available data provide valuable insight into the characteristics that could be associated with a more effective intervention. Namely, successful trials tended to use emollients with an acidic pH of 5.5, applied over the entire body, and combined with topical corticosteroids in affected areas. Consensus on the optimal strategy to restore skin barrier function could help improve the homogeneity and clinical relevance of future trials on this topic. In the meantime, clinicians should avoid products associated with worse outcomes.

The Prevalence of IgE-Mediated Food Allergy and Other Allergic Diseases in the First 10 Years: The Population-Based, Longitudinal HealthNuts Study

BACKGROUND

There are limited longitudinal data on the population prevalence of allergic conditions during childhood, and few studies have incorporated the reference standard oral food challenge to confirm food allergy.

OBJECTIVE

To describe the population prevalence of IgE-mediated food allergy, eczema, asthma, and rhinitis at ages 6 and 10 years in Melbourne, Australia.

METHODS

The HealthNuts study recruited 5,276 1-year-old infants in Melbourne, Australia, with repeat assessments at ages 6 and 10 years. At ages 6 and 10 years, carers completed a questionnaire on symptoms and doctor diagnosis of allergic conditions (International Study of Asthma and Allergies in Children). Children were invited to attend a clinic assessment including skin prick test, lung function tests, and oral food challenges when indicated. To minimize the impact of attrition bias, prevalence estimates among participants at ages 6 and 10 years were weighted to reflect characteristics of the whole cohort at recruitment.

RESULTS

In total, 4,455 and 4,065 families participated at ages 6 and 10 years, respectively (84% and 77% of the original cohort). Of those, 73% and 55% of participants ages 6 and 10 years, respectively, completed clinical assessments. Overall, 36.5% (95% CI, 34.8-38.2) and 38.2% (95% CI, 36.5-40.1%) of 6- and 10-year-olds had at least one current allergic disease, and around one third of those had two or more allergic diseases. Food allergy occurred in 6.4% (95% CI, 5.6-7.2) of 6-year olds and 6.3% (95% CI, 5.5-7.2) of 10-year-olds. Among infants with challenge-confirmed food allergy in infancy, 45% had persistent disease at age 10 years. The prevalence of current diagnosed asthma at ages 6 and 10 years were 12.1% (95% CI, 10.9-13.3) and 13.1% (95% CI, 11.9-14.4), respectively, current eczema decreased slightly from 15.3% (95% CI, 14.1-19.7) at age 6 years to 12.9% (95% CI, 11.7-14.2) at age 10 years, and current rhinitis increased from 15.1% (95% CI, 13.9-16.5) at age 6 years to 25.0% (95% CI, 23.4-26.7) at age 10 years.

CONCLUSIONS

Allergic diseases affect 40% of primary school-age children; one third have multiple allergic diagnoses. Challenge-confirmed food allergy prevalence remains high, and 45% of infants with food allergy have persistent disease to age 10 years.

Shared decision-making in food allergy: Navigating an exciting era

OBJECTIVE

Shared decision-making (SDM) is increasingly used in food allergy. We review its use in the areas of prevention, diagnosis, and management.

DATA SOURCES

PubMed and online SDM resources.

STUDY SELECTIONS

Studies and reviews relevant to SDM and areas in food allergy that decision-making may be applied were selected for discussion.

RESULTS

Food allergy represents an area with multiple opportunities for SDM. Patients, on one hand, need to obtain the necessary information and understanding of existing options from the allergist. The allergist, on the other hand, needs to understand "where the patient is coming from," their needs, preferences, and values, so that jointly they can reach a decision that is responsive to these. Benefits of SDM include a better understanding of disease by patients, improved compliance with medication, better health outcomes, decreased health care costs, and improved ability of patients to manage their disease and make informed choices.

CONCLUSION

In food allergy prevention, diagnosis, and management, multiple preference-sensitive options exist for patients where SDM may be used during allergy consultations, alongside decision aids. Decision aids are tools that assist and support patients during the SDM process, by supplementing the patient-physician interaction.

The Natural History and Risk Factors for the Development of Food Allergies in Children and Adults

PURPOSE OF REVIEW

This narrative review explores food allergy prevalence and natural history stratified by life stages, especially in context of evolving knowledge over the last few decades.

RECENT FINDINGS

The prevalence of food allergy remains highest in early childhood with common food triggers being cow's milk, soy, hen's egg, wheat, peanut, tree nuts, sesame, fish, and shellfish. This correlates with certain risk factors especially pertinent in the postnatal period which appear to predispose an individual to developing a food allergy. Some allergies (such as milk and egg) were previously thought to be easily outgrown in early life; however, recent studies suggest increasing rates of persistence of these allergies into young adulthood; the reason behind this is unknown. Despite this, there is also evidence demonstrating that food allergies can be outgrown in adolescents and adults. An understanding of the paradigm shifts in the natural history of food allergy allows clinicians to provide updated, age-appropriate, and tailored advice for patients on the management and prognosis of food allergy.

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

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

Epidemiology and the Growing Epidemic of Food Allergy in Children and Adults Across the Globe

PURPOSE OF REVIEW

Food allergies are immune-mediated, complex disorders, which are the source of increasing health concern worldwide. The goal of this review is to present an updated summary of the food allergy (FA) burden among children and adults across different populations, focusing on research from the past 5 years.

RECENT FINDINGS

FAs impact a growing number of global residents-particularly those residing in higher-income, industrialized regions. Moreover, growing epidemiologic evidence suggests that the population health burden of non-IgE-mediated FAs, such as food protein-induced enterocolitis syndrome, may also be higher than previously reported. FA is a complex trait that impacts infants, children, as well as adults across the globe. The population health burden of both IgE- and non-IgE-mediated FAs is likely to grow in the absence of rapid advances and widespread implementation of effective FA prevention and treatment interventions. Systematic epidemiological research initiatives are needed, both nationally and globally, to better understand and reduce the burden of these allergic diseases.

Risk subgroups and intervention effects among infants at high risk for peanut allergy: A model for clinical decision making

BACKGROUND

The Learning Early About Peanut Allergy (LEAP) trial showed that early dietary introduction of peanut reduced the risk of developing peanut allergy by age 60 months in infants at high risk for peanut allergy. In this secondary analysis of LEAP data, we aimed to determine risk subgroups within these infants and estimate their respective intervention effects of early peanut introduction.

METHODS

LEAP raw data were retrieved from ITNTrialShare.org. Conditional random forest was applied to participants in the peanut avoidance arm to select statistically important features for the classification and regression tree (CART) analysis to group infants based on their risk of peanut allergy at 60 months of age. Intervention effects were estimated for each derived risk subgroup using data from both arms. Our main model was generated based on baseline data when the participants were 4-11 months old. Specific IgE measurements were truncated to account for the limit of detection commonly used by laboratories in clinical practice.

RESULTS

The model found infants with higher predicted probability of peanut allergy at 60 months of age had a similar relative risk reduction, but a greater absolute risk reduction in peanut allergy with early introduction of peanut, than those with lower probability. The intervention effects were significant across all risk subgroups. Participants with baseline peanut sIgE ≥0.22 kU/L (n = 78) had an absolute risk reduction of 40.4% (95% CI 27.3, 51.9) whereas participants with baseline peanut sIgE<0.22 kU/L and baseline Ara h 2 sIgE <0.10 kU/L (n = 226) had an absolute risk reduction of 6.5% (95% CI 2.6, 11.0). These findings were consistent in sensitivity analyses using alternative models.

CONCLUSION

In this study, risk subgroups were determined among infants from the LEAP trial based on the probability of developing peanut allergy and the intervention effects of early peanut introduction were estimated. This may be relevant for further risk assessment and personalized clinical decision-making.

Revised Swedish infant feeding guidelines are associated with earlier introduction of allergenic foods

BACKGROUND

Randomized controlled trials have demonstrated that early introduction of allergenic foods, such as peanut and egg, can reduce food allergy in high-risk children. Many international guidelines recommend introduction of allergenic foods in the first year of life, and accordingly, the Swedish National Food agency released updated guidelines in June 2019.

OBJECTIVE

Our aim was to examine whether the age at introduction and consumption frequency of allergenic foods have changed since release of the revised national guidelines on the introduction of solid foods in Sweden.

METHODS

Children born between June 2016 and December 2018 (n = 1925) were compared with children born between June 2019 and April 2021 (n = 1761) by using data from the NorthPop Birth Cohort study. Data on food introduction, eczema, and food allergy were prospectively collected until age 18 months by using web-based questionnaires. IgE sensitization was assessed at 18 age months.

RESULTS

The proportion of participants who had been introduced to egg, legume, soy products, peanut, almond, and cashew nut during the first year of life increased after implementation of the revised national guidelines. The most significant changes were seen for legume (from 55.2% to 69.8% [adjusted odds ratio = 1.90 (95% CI = 1.62-2.24)]) and peanut (from 29.2% to 43.2% adjusted odds ratio = 1.87 (95% CI = 1.55-2.24)]); consumption frequency had also increased. No differences in the prevalence of eczema, food allergy, or sensitization to the foods of interest were found.

CONCLUSION

Since release of the revised guidelines, infants in the general population are introduced to and consume a variety of allergenic foods earlier and more frequently; however, early manifestations of allergic disease have remained unchanged.

Infantile peanut introduction and peanut allergy in regions with a low prevalence of peanut allergy: the Japan Environment and Children's Study (JECS)

BACKGROUND

In regions with a high prevalence of peanut allergy (PA), there is a consensus that the introduction of peanuts in early infancy is preventive against the development of PA. However, few studies have investigated whether the introduction of peanuts to infants is associated with PA in regions with a low prevalence of PA, including Japan.

METHODS

We used data from 74,240 mother-child pairs who participated in the Japan Environment and Children's Study, a prospective birth cohort recruited between January 2011 and March 2014. A logistic regression model was used to analyze the association between infantile peanut introduction and PA at the age of 4 years with non-infantile peanut introduction as the reference group, adjusted for potential confounders.

RESULTS

The percentage of infantile peanut introduction was 4.9% (n=3294) and 286 (0.4%) participants had allergic symptoms to peanuts at 4 years of age. Of all participants, 129 (0.2%) had PA at 4 years of age, which was defined as allergic symptoms and sensitization to peanuts. Those with infantile peanut introduction had a lower prevalence of PA than those without infantile peanut introduction, although this did not reach statistical significance (adjusted odds ratio: 0.53, 95% confidence interval, 0.17-1.68). Sensitivity analysis using IgE-mediated symptoms caused by peanuts as the outcome showed a similar result in relation to infantile peanut introduction.

CONCLUSIONS

In countries with a low prevalence of PA, the effect of infantile peanut introduction on PA prevention was unclear.

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.

Australian Infant Food Allergy Emergency Presentations Following Updated Early Food Introduction Guidelines

BACKGROUND

The Australasian Society of Clinical Immunology and Allergy food allergy prevention guidelines were updated in 2016 to recommend home introduction of allergenic foods actively in the first year of life, including to infants at high risk of allergy. An important consideration for parents and providers is whether this practice increases food allergy reactions or anaphylaxis.

OBJECTIVE

We aimed to determine whether the 2016 update of food allergy prevention guidelines was associated with an increase in food allergy or anaphylaxis emergency department (ED) presentations.

METHODS

We obtained hospital electronic medical records for infants aged 4 to 12 months who attended the Royal Children's Hospital Melbourne ED in 2015 or in 2018 with a presenting problem or an encounter diagnosis of food allergy or anaphylaxis.

RESULTS

Emergency department presentations owing to food allergy increased from 1.0% (95% CI, 0.85-1.23) in 2015 to 1.4% (95% CI, 1.22-1.67) in 2018 (P = .006). There was no increase in the number of anaphylaxis presentations (28 in 2015 and 22 in 2018) or peanut anaphylaxis presentations (three in 2015 and three in 2018). Overall, the proportion of food allergy presentations attributed to IgE-mediated food allergy was similar (82.1% in 2015 and 84.1% in 2018), whereas peanut allergy presentations increased slightly, although not statically significantly, from 14.6% to 21.2% (P = .09). Food protein-induced enterocolitis syndrome ED presentations were five in 2015 (4.3%) and 12 in 2018(7.6%), although not statistically significant (P = .25).

CONCLUSIONS

Changes to food allergy prevention guidelines recommending the earlier introduction of allergenic food may have led to a small increase in ED presentations for food allergy but not anaphylaxis.

Early Peanut Immunotherapy in Children (EPIC) trial: protocol for a pragmatic randomised controlled trial of peanut oral immunotherapy in children under 5 years of age

INTRODUCTION

Food allergy is a major public health challenge in Australia. Despite widespread uptake of infant feeding and allergy prevention guidelines the incidence of peanut allergy in infants has not fallen, and prevalence of peanut allergy in school-aged children continues to rise. Therefore, effective and accessible treatments for peanut allergy are required. There is high-quality evidence for efficacy of oral immunotherapy in children aged 4-17 years old; however, few randomised trials have investigated peanut oral immunotherapy (OIT) in young children. Furthermore, the use of food products for OIT with doses prepared and administered by parents without requiring pharmacy compounding has the potential to reduce costs associated with the OIT product.

METHODS AND ANALYSIS

Early Peanut Immunotherapy in Children is an open-label randomised controlled trial of peanut OIT compared with standard care (avoidance) to induce desensitisation in children aged 1-4 years old with peanut allergy. n=50 participants will be randomised 1:1 to intervention (daily peanut OIT for 12 months) or control (peanut avoidance). The primary outcome is the proportion of children in each group with a peanut eliciting dose >600 mg peanut protein as assessed by open peanut challenge after 12 months, analysed by intention to treat. Secondary outcomes include safety as assessed by frequency and severity of treatment-related adverse events, quality of life measured using age-appropriate food allergy-specific questionnaires and immunological changes during OIT.

ETHICS

The trial is approved by the Child and Adolescent Health Service Human Research Ethics Committee and prospectively registered with the Australia and New Zealand Clinical Trials Registry.

DISSEMINATION

Trial outcomes will be published in a peer-review journal and presented and local and national scientific meetings.

TRIAL REGISTRATION NUMBER

ACTRN12621001001886.

The First 1000 Days of Life: How Changes in the Microbiota Can Influence Food Allergy Onset in Children

BACKGROUND

Allergic disease, including food allergies (FA)s, has been identified as a major global disease. The first 1000 days of life can be a "window of opportunity" or a "window of susceptibility", during which several factors can predispose children to FA development. Changes in the composition of the gut microbiota from pregnancy to infancy may play a pivotal role in this regard: some bacterial genera, such as Lactobacillus and Bifidobacterium, seem to be protective against FA development. On the contrary, Clostridium and Staphylococcus appear to be unprotective.

METHODS

We conducted research on the most recent literature (2013-2023) using the PubMed and Scopus databases. We included original papers, clinical trials, meta-analyses, and reviews in English. Case reports, series, and letters were excluded.

RESULTS

During pregnancy, the maternal diet can play a fundamental role in influencing the gut microbiota composition of newborns. After birth, human milk can promote the development of protective microbial species via human milk oligosaccharides (HMOs), which play a prebiotic role. Moreover, complementary feeding can modify the gut microbiota's composition.

CONCLUSIONS

The first two years of life are a critical period, during which several factors can increase the risk of FA development in genetically predisposed children.

Making a SmartStart for peanut introduction to support food allergy prevention guidelines for infants

Background

Food allergy affects up to 10% of Australian infants. It was hypothesized that if parents follow the Australasian Society of Clinical Immunology and Allergy guidelines, Australian food allergy rates may stabilize or decline.

Objective

This project aimed to determine whether SmartStartAllergy influenced parental introduction of peanut by age 12 months, including in high-risk infants.

Methods

SmartStartAllergy integrates with general practice management software to send text messages to parents via participating general practices. The intervention group participants were sent text messages when their child was aged 6, 9, and 12 months; the control group participants were parents of 12-month-old infants. When their child was aged 12 months, all participants completed a questionnaire regarding eczema and family history of atopy. Infants with severe eczema and/or a family history of atopy were considered high-risk.

Results

Between 21 September 2018 and 26 April 2022, a total of 29,092 parents were enrolled in SmartStartAllergy as intervention (n = 18,090) and control (n = 11,002) group members The intervention group was more likely to introduce peanut by 12 months (crude odds ratio = 5.18; P < .0001; 95% CI = 4.35-6.16). After adjustment for the infants' level of risk and family history of atopy and food allergy, the intervention group was more likely to introduce peanut by 12 months of age (adjusted odds ratio = 5.34; P < .01; 95% CI = 4.48-6.37).

Conclusion

SmartStartAllergy appears to be an effective tool for encouraging parental introduction of peanut. The ability to provide parents with credible allergy prevention information, along with the capacity to collect simple responses via text along with additional information via an online questionnaire, make this a useful public health tool.

Peanut butter feeding induces oral tolerance in genetically diverse collaborative cross mice

Background

Early dietary introduction of peanut has shown efficacy in clinical trials and driven pediatric recommendations for early introduction of peanut to children with heightened allergy risk worldwide. Unfortunately, tolerance is not induced in every case, and a subset of patients are allergic prior to introduction. Here we assess peanut allergic sensitization and oral tolerance in genetically diverse mouse strains.

Objective

We aimed to determine whether environmental adjuvant-driven airway sensitization and oral tolerance to peanut could be induced in various genetically diverse mouse strains.

Methods

C57BL/6J and 12 Collaborative Cross (CC) mouse strains were fed regular chow or ad libitum peanut butter to induce tolerance. Tolerance was tested by attempting to sensitize mice via intratracheal exposure to peanut and lipopolysaccharide (LPS), followed by intraperitoneal peanut challenge. Peanut-specific immunoglobulins and peanut-induced anaphylaxis were assessed.

Results

Without oral peanut feeding, most CC strains (11/12) and C57BL/6J induced peanut-specific IgE and IgG1 following airway exposure to peanut and LPS. With oral peanut feeding none of the CC strains nor C57BL/6J mice became sensitized to peanut or experienced anaphylaxis following peanut challenge.

Conclusion

Allergic sensitization and oral tolerance to peanut can be achieved across a range of genetically diverse mice. Notably, the same strains that became allergic via airway sensitization were tolerized by feeding high doses of peanut butter before sensitization, suggesting that the order and route of peanut exposure are critical for determining the allergic fate.

The future of food allergy: Challenging existing paradigms of clinical practice

The field of food allergy has seen tremendous change over the past 5-10 years with seminal studies redefining our approach to prevention and management and novel testing modalities in the horizon. Early introduction of allergenic foods is now recommended, challenging the previous paradigm of restrictive avoidance. The management of food allergy has shifted from a passive avoidance approach to active interventions that aim to provide protection from accidental exposures, decrease allergic reaction severity and improve the quality of life of food-allergic patients and their families. Additionally, novel diagnostic tools are making their way into clinical practice with the goal to reduce the need for food challenges and assist physicians in the-often complex-diagnostic process. With all the new developments and available choices for diagnosis, prevention and therapy, shared decision-making has become a key part of medical consultation, enabling patients to make the right choice for them, based on their values and preferences. Communication with patients has also become more complex over time, as patients are seeking advice online and through social media, but the information found online may be outdated, incorrect, or lacking in context. The role of the allergist has evolved to embrace all the above exciting developments and provide patients with the optimal care that fits their needs. In this review, we discuss recent developments as well as the evolution of the field of food allergy in the next decade.

Enhanced early skin treatment for atopic dermatitis in infants reduces food allergy

BACKGROUND

Early-onset atopic dermatitis is a strong risk factor for food allergy, suggesting that early effective treatment may prevent transcutaneous sensitization.

OBJECTIVES

This study tested whether enhanced treatment of atopic dermatitis to clinically affected and unaffected skin is more effective in preventing hen's egg allergy than reactive treatment to clinically affected skin only.

METHODS

This was a multicenter, parallel-group, open-label, assessor-blind, randomized controlled trial (PACI [Prevention of Allergy via Cutaneous Intervention] study). This study enrolled infants 7-13 weeks old with atopic dermatitis and randomly assigned infants in a 1:1 ratio to enhanced early skin treatment or conventional reactive treatment using topical corticosteroids (TCSs). The primary outcome was the proportion of immediate hen's egg allergy confirmed by oral food challenge at 28 weeks of age.

RESULTS

This study enrolled 650 infants and analyzed 640 infants (enhanced [n = 318] or conventional [n = 322] treatment). Enhanced treatment significantly reduced hen's egg allergy compared with the conventional treatment (31.4% vs 41.9%, P = .0028; risk difference: -10.5%, upper bound of a 1-sided CI: -3.0%), while it lowered body weight (mean difference: -422 g, 95% CI: -553 to -292 g) and height (mean difference: -0.8 cm, 95% CI: -1.22 to -0.33 cm) at 28 weeks of age.

CONCLUSIONS

This study highlighted the potential of well-controlled atopic dermatitis management as a component of a hen's egg allergy prevention strategy. The enhanced treatment protocol of this trial should be modified before it can be considered as an approach to prevent hen's egg allergy in daily practice to avoid the adverse effects of TCSs. After remission induction by TCSs, maintenance therapy with lower potency TCSs or other topical therapies might be considered as alternative proactive treatments to overcome the safety concerns of TCSs.

Defining the window of opportunity and target populations to prevent peanut allergy

BACKGROUND

Peanut allergy affects 1% to 2% of European children. Early introduction of peanut into the diet reduces allergy in high-risk infants.

OBJECTIVE

We aimed to determine the optimal target populations and timing of introduction of peanut products to prevent peanut allergy in the general population.

METHODS

Data from the Enquiring About Tolerance (EAT; n = 1303; normal risk; 3-year follow-up; ISRCTN14254740) and Learning Early About Peanut Allergy study (LEAP; n = 640; high risk; 5-year follow-up; NCT00329784) randomized controlled trials plus the Peanut Allergy Sensitization (PAS; n = 194; low and very high risk; 5-year follow-up) observational study were used to model the intervention in a general population. Peanut allergy was defined by blinded peanut challenge or diagnostic skin prick test result.

RESULTS

Targeting only the highest-risk infants with severe eczema reduced the population disease burden by only 4.6%. Greatest reductions in peanut allergy were seen when the intervention was targeted only to the larger but lower-risk groups. A 77% reduction in peanut allergy was estimated when peanut was introduced to the diet of all infants, at 4 months with eczema, and at 6 months without eczema. The estimated reduction in peanut allergy diminished with every month of delayed introduction. If introduction was delayed to 12 months, peanut allergy was only reduced by 33%.

CONCLUSIONS

The preventive benefit of early introduction of peanut products into the diet decreases as age at introduction increases. In countries where peanut allergy is a public health concern, health care professionals should help parents introduce peanut products into their infants' diet at 4 to 6 months of life.

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.

Prevention of food allergy in infancy: the role of maternal interventions and exposures during pregnancy and lactation

There is increased focus on the role of maternal interventions in the prevention of food allergy in infancy. There is no role for maternal dietary modifications during pregnancy or lactation, such as allergen avoidance, as a means of infant allergy prevention. Although exclusive breastfeeding is the recommended infant nutrition source globally, the effect of breastfeeding on infant allergy prevention remains unclear. There is emerging evidence that irregular cow's milk exposure (ie, infrequent formula supplementation) might increase the risk of cow's milk allergy. Although further studies are required, there is also emerging evidence that maternal peanut ingestion during breastfeeding along with early peanut introduction in infancy might have a preventive role. The effect of maternal dietary supplementation with vitamin D, omega-3, and prebiotics or probiotics remains unclear.

Early Peanut Introduction in Primary Care: Evaluation of a Multicomponent Intervention

OBJECTIVE

To determine whether a multicomponent intervention focused on early peanut introduction was associated with a lower peanut allergy incidence in young children.

METHODS

The study cohort comprised all children born January 1, 2013 through December 31, 2018 receiving care at a large health care organization. Intervention activities occurred over 16 months and included provider educational programs, electronic health record tools, and new patient instructions. We used an interrupted time series design to assess whether peanut allergy incidence differed across 3 time periods (preintervention, interim, postintervention) among high- and low-risk children. The primary outcome was incident peanut allergy by age 24 months, defined as peanut allergy in the allergy field or active problem list plus a positive supportive test. Severe eczema and/or egg allergy presence defined high-risk. Because the study was conducted as part of routine care, it was not feasible to measure what counseling clinicians provided, or how and when parents fed their children peanut-containing foods.

RESULTS

In a cohort of 22,571 children, the percent with peanut allergy by age 24 months was 17.3% (116 of 671) among high-risk and 0.8% (181 of 21,900) among low-risk children. In multivariate analyses, the adjusted peanut allergy rate per 100 person-years was not significantly different across study periods among high-risk (9.6 preintervention, 11.7 interim, and 9.9 postintervention, P = .70) or low-risk (0.5 preintervention, 0.7 interim, and 0.5 postintervention, P = .17) children.

CONCLUSIONS

In a community-based setting, the incidence of peanut allergy did not decline following a multicomponent intervention focused on early peanut introduction.

Early peanut introduction: To test or not to test?

OBJECTIVE

To review recent evidence and international guidelines on early peanut introduction for preventing peanut allergy and provide an update on the status of the debate around testing before early peanut introduction.

DATA SOURCES

Review of published literature documenting: infant feeding guidelines; impact of early peanut introduction on peanut allergy; risk factors for peanut allergy; and impact of early peanut introduction guidelines on infant feeding practices and allergy.

STUDY SELECTION

We used a narrative approach and present both pro and con arguments for testing before peanut introduction. Data from randomized controlled trials and post-hoc analyses of these trials and observational studies were included.

RESULTS

Allergy prevention guidelines around the world now consistently recommend introducing peanut into an infant's diet before 12 months of age for countries with high peanut allergy prevalence. In the US, guidelines recently shifted away from recommending allergy testing before introduction for those at risk of peanut allergy. There is evidence primarily from Australia that recommending early introduction without prior testing is safe and effective in increasing early peanut introduction for both high and low-risk infants, although the subsequent reduction in peanut allergy prevalence at the population level was less than expected.

CONCLUSION

Current evidence supports recommending early peanut introduction without routinely testing for peanut allergy. If testing is offered, this should be based on shared decision making between families and practitioners and only be undertaken where there is provision for rapid access to definitive diagnosis including oral food challenges.

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.

Food Allergy and Eosinophilic Gastrointestinal Diseases-The Next 10 Years

The first report of food allergy desensitization was in 1908, at least a few years before the first published description of a diagnostic test for food allergy. It has taken almost 100 years for food allergy to move from passive management of avoidance to a more proactive approach including prevention and treatment. In parallel, this has been matched by recognition of eosinophil gastrointestinal diseases, which were first described in the 1980s (although eosinophilic esophagitis was itself described in 1978). As we celebrate 10 years of The Journal of Allergy and Clinical Immunology: In Practice, we take the opportunity to look into the future and speculate how our practice may develop over the next decade.

Food allergen introduction patterns in the first year of life: A US nationwide survey

BACKGROUND

Prevention guidelines have changed over the past decade and now recommend the earlier introduction of peanut and egg without delaying the introduction of other food allergens. This paper explored caregiver practices regarding the introduction of food allergens during infancy.

METHODS

A survey was administered (2021) to a US population-based sample of 3062 caregivers (children 7 months - 3.5 years). Demographics and feeding practices were collected. Weighted frequencies and proportions were calculated using the svyr package in R 4.1. Survey-weighted chi-square statistics and covariate-adjusted, survey-weighted logistic regression models were used for statistical inference.

RESULTS

Cow's milk, wheat, and soy were the top three allergens introduced. Peanut and egg were introduced by 17.2% and 15.5% of caregivers before 7 months and 58.8% and 66.4% before 1 year, respectively. The age of peanut and egg introduction differed significantly by race/ethnicity (p < .001) and caregiver age (p < .001). Peanut and egg introduction before 7 months was significantly associated with the increased introduction of other allergenic foods before 1 year (p = <.001; peanut and p = < .001; egg). Caregivers who introduced peanut and egg before 7 months infant age fed an additional mean of 5.4 and 4.5 food allergens, respectively, before 1 year. Few caregivers (0.9%) reported feeding an "early food allergen introduction product" ≥ 3 times, which was significantly associated with parental food allergy (OR = 2.2) and previously seen an allergist (OR = 6.7).

CONCLUSION

More than half of the caregivers are not introducing peanut by age of one year and one-third are not introducing egg, though an observed shift toward earlier peanut and egg introduction was seen in the past 5 years. Peanut and egg introduction seem to co-occur and are associated with increased intake of other food allergens.

A pragmatic approach to infant feeding for food allergy prevention

Early introduction of allergenic foods into an infant's diet is currently the most promising strategy to prevent food allergy, with infant guidelines around the world shifting from promoting avoidance to actively encourage the introduction of allergenic foods in the infant diet. Infant feeding guidelines vary according to regional public health priorities, and knowledge gaps remain, resulting in ongoing challenges for clinicians and families to translate guidelines into practical strategies for the introduction of complementary foods for food allergy prevention. Evidence from Australia demonstrates high community support and uptake of revised guidelines with most parents introducing allergenic foods in the first year of life, although this has not had the expected impact on substantially reducing food allergy prevalence. To uptake of guidelines from other countries is less clear, and several barriers have been noted in infant feeding RCTs, which may warrant intervention strategies. Further research is needed to understand additional strategies for food allergy prevention, particularly in infants who develop food allergy prior to when they are developmentally ready to commence solids. Several RCTs are underway investigating preventative strategies that target the window before allergen ingestion, such as vitamin D supplementation, emollient use, and immunizations that prime the immune response away from a Th2-driven allergic phenotype. Further research is also needed to understand the role of the environment and the host environment in the development of tolerance to foods.