Food allergy prevention through the decades: An ounce of humility is worth a pound of cure.

Food allergy prevention has undergone a significant transformation over the past 3 decades. This review provides an overview of the evolution of food allergy prevention, highlighting changes in guidance, cost-effectiveness of prevention, the role of shared decision-making, and the emergence of oral immunotherapy for those in whom primary prevention fails. Changes to food allergy prevention over recent decades can be conceptualized into five epochs, which have followed a general trend of loosening restrictions on the allergen introduction timeline. These epochs are characterized by significant maternal and infant dietary restrictions in the "universal avoidance epoch"(-1990), loosened maternal diet restrictions in the "infant avoidance epoch" (1990-2000), a time-bound allergen introduction schedule in the "stratified avoidance epoch" (2000-2010), retraction of recommendations in the "corrective retraction epoch" (2010-2015), and endorsement of early allergen introduction in the "early introduction epoch" (2015-present), the start of which is marked by the 2015 Learning Early About Peanut study. In hindsight, it is clear that certain recommendations from previous decades were not the best course of action. A no-screening early introduction approach to food allergy prevention is both cost-effective and beneficial to patient quality of life.

Assessing the Effect of Infant Peanut Exposure Guidelines on Peanut Aspiration Using Google Trends Search Analysis.

Background The American Academy of Pediatrics (AAP) changed guidelines in 2017 to recommend introducing infants to peanuts as early as four months. Peanuts are also one of the most commonly aspirated food-related foreign bodies. Google Trends search pattern analysis has been validated in epidemiologic research as being reflective of healthcare events. Methodology Google Trends measures the popularity of a search term in a given week compared to the popularity of all search terms in that week, calculated as relative search volume (RSV), yielding a value between 0 and 100. We compiled peanut aspiration-related search data from January 2012 to January 2022 and compared the relative popularity of these searches before the change in guidelines to after. Results All queried search terms significantly increased in RSV when comparing the five years before and following January 2017. When pooling all terms, the median RSV increase was 13.8% (p < 0.001). "Choke on peanut" and the combination of peanut and cough had the highest median RSV increases from 9.6 to 17 and 50.8 to 63.1, respectively. Conclusions The change in 2017 of the AAP guidelines on early childhood peanut exposure was associated with an increase in online searches for peanut aspiration. This may be reflective of increased aspiration events, or possibly increased concern for aspiration. Current results support the need to closely counsel families on infant-safe peanut products to prevent dangerous aspiration events.

Effect of mothers' health literacy on early childhood allergy prevention behaviours: results from the KUNO-Kids health study.

BACKGROUND: Parents can engage in several behaviours with regard to early childhood allergy prevention (ECAP). These can be related to diet of mother/child and the modification of the home environment; not all of them are justified by current evidence. Previous studies showed that parental health literacy (HL) is related to favourable health behaviours directed at the child. This study aimed to investigate the causal effect of mothers' HL on ECAP behaviours and to test different moderators of this effect. METHODS: One thousand six hundred sixty-two mothers participating in the KUNO-Kids health study in the area of Regensburg, Germany were surveyed on HL (assessed via the health care scale of the Health Literacy Survey-EU questionnaire, HLS-EU-Q47) and ECAP behaviours implemented during pregnancy and the child's first year of life. Patterns in ECAP behaviours were identified by latent class analysis. Multinomial regression modelling was performed with HL as exposure, ECAP as outcome variable, allergy risk, parental competence and bonding, anxiety and depression as moderators as well as potentially confounding variables. RESULTS: We identified three classes of ECAP behaviours (class 1: "breastfeeding " N = 871; class 2: "allergen-avoidance " N = 490; class 3: "mixed behaviours " N = 301). In univariable as well as fully adjusted regression models, compared to class 1, class 2 was negatively, and class 3 was not associated with HL. None of the tested moderating variables altered the association between HL and ECAP significantly. CONCLUSIONS: We found an effect of mothers' HL on ECAP behaviours: lower HL of mothers increased allergen-avoiding behaviour directed at their child, while decreasing the chance of exclusive breastfeeding. Improving HL could contribute to the implementation of recommended ECAP behaviours in families, especially to the reduction of allergen-avoiding behaviours.

Effects of pregnancy and lactation prebiotics supplementation on infant allergic disease: A randomized controlled trial.

BACKGROUND: Ingestion of prebiotics during pregnancy and lactation may have immunomodulatory benefits for the developing fetal and infant immune system and provide a potential dietary strategy to reduce the risk of allergic diseases. OBJECTIVE: We sought to determine whether maternal supplementation with dietary prebiotics reduces the risk of allergic outcomes in infants with hereditary risk. METHODS: We undertook a double-blind randomized controlled trial in which pregnant women were allocated to consume prebiotics (14.2 g daily of galacto-oligosaccharides and fructo-oligosaccharides in the ratio 9:1) or placebo (8.7 g daily of maltodextrin) powder from less than 21 weeks' gestation until 6 months postnatal during lactation. Eligible women had infants with a first-degree relative with a history of medically diagnosed allergic disease. The primary outcome was medically diagnosed infant eczema by age 1 year, and secondary outcomes included allergen sensitization, food allergy, and recurrent wheeze by age 1 year. RESULTS: A total of 652 women were randomized between June 2016 and November 2021 (329 in the prebiotics group and 323 in the placebo group). There was no significant difference between groups in the percentage of infants with medically diagnosed eczema by age 1 year (prebiotics 31.5% [103 of 327 infants] vs placebo 32.6% [105 of 322 infants]; adjusted relative risk, 0.98; 95% CI, 0.77-1.23; P = .84). Secondary outcomes and safety measures also did not significantly differ between groups. CONCLUSIONS: We found little evidence that maternal prebiotics supplementation during pregnancy and lactation reduces the risk of medically diagnosed infant eczema by age 1 year in infants who are at hereditary risk of allergic disease.

Sources of Allergens Detected Through Allergen-Specific Serum IgE Antibody Test in Children with Suspected Allergic Diseases in Central China.

Purpose: Although allergic diseases in children are on the rise, there has been no comprehensive investigation of the allergens affecting children with allergic diseases in central China. Therefore, we aimed to analyze the distribution of serum allergen species among children with allergic conditions in central China to inform the prevention, diagnosis, and treatment of childhood allergies. Patients and Methods: A total of 9213 children (5543 males with 2.88 ± 0.04 years old and 3670 females with 2.91 ± 0.05 years old) underwent allergen screening, and serum allergen-specific IgE (sIgE) antibodies were detected using an automated fluorescent enzyme immunoassay system. Results: Our findings revealed a total sIgE-positive rate (sIgE-PR) of 57.83%, with mixed food (42.10%), egg whites (30.83%), milk (28.97%), mixed dust mites (24.57%), and mixed molds (23.20%) being the most prevalent source of allergens. The sIgE-PR for common sources of allergens exhibited significant sex-based differences, with males having greater susceptibility than females (p<0.05). Dust mites were the primary source of inhaled allergens, whereas egg white was the predominant source of food allergens. Sources of food allergens were most dominant among infants (0-3 years old); sIgE-PRs for most source of food allergens decreased with age, whereas those for most source of inhaled allergens increased. The autumn sIgE-PRs for mixed molds, weed pollen combinations, and tree pollen combinations were significantly higher than those found in other seasons (p<0.05). Conclusion: Our findings suggest that sources of allergens profiles in children with allergies vary across age groups and seasons. Understanding these patterns can improve the effective prevention of childhood allergies.

Awareness and Application of United States Food Allergy Prevention Guidelines Among Pediatricians and Other Clinicians.

OBJECTIVE: To characterize the awareness of, adherence to, and barriers to the 2017 National Institute of Allergy and Infectious Diseases (NIAID) peanut allergy prevention guidelines among the pediatrics health care workforce. STUDY DESIGN: Pediatricians, family physicians, advanced practice providers (APPs), and dermatologists who provide care for infants were solicited for a population-based online survey, administered from June 6, 2022, through July 3, 2022. The survey collected information about NIAID guideline awareness, implementation, and barriers as well as concerns related to the guidelines. RESULTS: A total of 250 pediatricians, 250 family physicians, 504 APPs, and 253 dermatologists met inclusion criteria. Self-reported guideline awareness was significantly higher for pediatricians (76%) compared with dermatologists (58%), family physicians (52%), and APPs (45%) (P < .05). Among participants who were aware of the guidelines, most reported using part or all of the guidelines in their clinical practices. Reported practice patterns for peanut introduction in 6-month-old infants were variable and did not always align with guidelines, particularly for infants with mild-to-moderate atopic dermatitis. CONCLUSIONS: Although pediatricians have the highest self-reported level of NIAID guideline awareness, awareness was suboptimal irrespective of provider type. Education for all pediatric clinicians is urgently needed to promote evidence-based peanut allergy prevention practices.

Health Promotion of Early and Sustained Allergenic Food Introduction for the Prevention of Food Allergy.

Observational studies and landmark randomized control trials support early and sustained allergenic food introduction in infancy as an effective preventive strategy against food allergy development. Despite a consensus regarding the intended goals of early and sustained allergenic food introduction, there have been myriad policy recommendations among health authorities in how to achieve both individual and population-level health outcomes for food allergy prevention. This clinical management review provides an overview on the data that informs early and sustained allergenic food introduction strategies, suggestions on how to advise allergenic food introduction, principles of prevention programs as they relate to food allergy prevention, and health promotion and systems-level challenges that impede achievement of food allergy prevention goals.

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.

Design of the Intervention to Reduce Early Peanut Allergy in Children (iREACH): A practice-based clinical trial.

BACKGROUND: Introducing peanut products early can prevent peanut allergy (PA). The "Addendum guidelines for the prevention of PA in the United States" (PPA guidelines) recommend early introduction of peanut products to low and moderate risk infants and evaluation prior to starting peanut products for infants at high risk for PA (those with severe eczema and/or egg allergy). Rapid adoption of guidelines could aid in lowering the prevalence of PA. The Intervention to Reduce Early (Peanut) Allergy in Children (iREACH) trial was designed to promote PPA guideline adherence by pediatric clinicians. METHODS: A two-arm, cluster-randomized, controlled clinical trial was designed to measure the effectiveness of an intervention that included clinician education and accompanying clinical decision support tools integrated in electronic health records (EHR) versus standard care. Randomization was at the practice level (n = 30). Primary aims evaluated over an 18-month trial period assess adherence to the PPA guidelines using EHR documentation at 4- and 6-month well-child care visits aided by natural language processing. A secondary aim will evaluate the effectiveness in decreasing the incidence of PA by age 2.5 years using EHR documentation and caregiver surveys. The unit of observation for evaluations are individual children with clustering at the practice level. CONCLUSION: Application of this intervention has the potential to inform the development of strategies to speed implementation of PPA guidelines.

Coupling of a Major Allergen to the Surface of Immune Cells for Use in Prophylactic Cell Therapy for the Prevention of IgE-Mediated Allergy.

Up to a third of the world's population suffers from allergies, yet the effectiveness of available preventative measures remains, at large, poor. Consequently, the development of successful prophylactic strategies for the induction of tolerance against allergens is crucial. In proof-of-concept studies, our laboratory has previously shown that the transfer of autologous hematopoietic stem cells (HSC) or autologous B cells expressing a major grass pollen allergen, Phl p 5, induces robust tolerance in mice. However, eventual clinical translation would require safe allergen expression without the need for retroviral transduction. Therefore, we aimed to chemically couple Phl p 5 to the surface of leukocytes and tested their ability to induce tolerance. Phl p 5 was coupled by two separate techniques, either by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) or by linkage via a lipophilic anchor, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-maleimide (DSPE-PEG-Mal). The effectiveness was assessed in fresh and cultured Phl p 5-coupled cells by flow cytometry, image cytometry, and immunofluorescence microscopy. Chemical coupling of Phl p 5 using EDC was robust but was followed by rapid apoptosis. DSPE-PEG-Mal-mediated linkage was also strong, but antigen levels declined due to antigen internalization. Cells coupled with Phl p 5 by either method were transferred into autologous mice. While administration of EDC-coupled splenocytes together with short course immunosuppression initially reduced Phl p 5-specific antibody levels to a moderate degree, both methods did not induce sustained tolerance towards Phl p 5 upon several subcutaneous immunizations with the allergen. Overall, our results demonstrate the successful chemical linkage of an allergen to leukocytes using two separate techniques, eliminating the risks of genetic modifications. More durable surface expression still needs to be achieved for use in prophylactic cell therapy protocols.

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

AIM: To investigate the routine guidance provided by pediatricians concerning the timing of complementary feeding (CF) for both healthy infants and those at a heightened risk of allergies. METHODS: A total of 233 pediatricians participated in an anonymous online survey that included questions about demographics and recommendations for CF. Specifically, they provided guidance on the types of foods, preparation methods, supplements, time intervals for introducing new foods to infants at low and high allergy risk, and delayed food introductions for high-risk cases. RESULTS: The respondents advised introducing certain foods at specific ages: fruits, starchy non-gluten grains, vegetables, olive oil, and meat were appropriate at 6 months; gluten-rich grains at 7 months; yogurt, hard-boiled eggs, and legumes at 8 months; fish at 8.5 months; and nuts at 9 months. Pediatricians, especially those with less than 15 years of practice, often introduced egg, seafood, gluten-rich grains, legumes, and nuts earlier for high-risk infants. Parenthood and male gender were associated with the earlier introduction of eggs and grains. CONCLUSIONS: Greek pediatricians follow a structured food introduction schedule for CF in infants. Interestingly, they tend to delay the introduction of common food allergens and recommend longer intervals between introducing new foods, particularly for high-risk infants. Key Notes: Despite recent evidence-based indications on healthy complementary feeding strategies for infants, discrepancies persist among pediatricians regarding food choices and the order and timing of food introduction, both for healthy infants and those at risk of allergy. Guidance on complementary feeding by pediatricians is influenced by their individual characteristics. Pediatricians tend to delay the introduction of common food allergens and recommend longer intervals between introducing new foods, particularly for high-risk infants.

Full Breastfeeding and Allergic Diseases-Long-Term Protection or Rebound Effects?

A previous follow-up of the GINIplus study showed that breastfeeding could protect against early eczema. However, effects diminished in adolescence, possibly indicating a "rebound effect" in breastfed children after initial protection. We evaluated the role of early eczema until three years of age on allergies until young adulthood and assessed whether early eczema modifies the association between breastfeeding and allergies. Data from GINIplus until 20-years of age (N = 4058) were considered. Information on atopic eczema, asthma, and rhinitis was based on reported physician's diagnoses. Adjusted Odds Ratios (aOR) were modelled by using generalized estimating equations. Early eczema was associated with eczema (aORs = 3.2-14.4), asthma (aORs = 2.2-2.7), and rhinitis (aORs = 1.2-2.7) until young adulthood. For eczema, this association decreased with age (p-for-interaction = 0.002-0.006). Longitudinal models did not show associations between breastfeeding and the respective allergies from 5 to 20 years of age. Moreover, early eczema generally did not modify the association between milk feeding and allergies except for rhinitis in participants without family history of atopy. Early eczema strongly predicts allergies until young adulthood. While preventive effects of full breastfeeding on eczema in infants with family history of atopy does not persist until young adulthood, the hypothesis of a rebound effect after initial protection cannot be confirmed.

A Survey of Canadian Dietitians on Identification of Infants at High Risk of Food Allergy and Frequency of Allergenic Food Consumption.

Purpose: To assess knowledge of Canadian dietitians on the topics of food allergy and food allergy prevention guidelines, including introduction of allergenic solids to infants at risk of food allergy.Methods: An online survey was distributed via email listservs targeting Canadian dietitians.Results: In total, 144 of 261 dietitians completed the survey (60.5%). Respondents recommend introduction of peanut (89.5%) and allergenic solids (91.2%) within the recommended age of 4-6 months for infants at high risk of food allergy, but only 26.2% recommend offering peanut three times per week once it has been introduced. In identifying what constitutes an infant at high risk of developing peanut allergy, dietitians expressed lower comfort levels and lower number of correct responses.Conclusions: Dietitians demonstrated they are up to date regarding the timing of introduction of allergenic solids, but not the frequency of consumption once introduced, for infants at high risk of food allergy. They also expressed low comfort level identifying risk factors for peanut allergy. There are opportunities for further education of dietitians, as well as potential to further utilize dietitian services for the benefit of patients with food allergy or who are at risk for food allergy.

How do parents access, appraise, and apply health information on early childhood allergy prevention? A focus group and interview study.

Background: When parents want to make health-related decisions for their child, they need to be able to handle health information from a potentially endless range of sources. Early childhood allergy prevention (ECAP) is a good example: recommendations have shifted from allergen avoidance to early introduction of allergenic foods. We investigated how parents of children under 3 years old access, appraise and apply health information about ECAP, and their respective needs and preferences. Methods: We conducted 23 focus groups and 24 interviews with 114 parents of children with varied risk for allergies. The recruitment strategy and a topic guide were co-designed with the target group and professionals from public health, education, and medicine. Data were mostly collected via video calls, recorded and then transcribed verbatim. Content analysis according to Kuckartz was performed using MAXQDA and findings are presented as a descriptive overview. Results: Parents most frequently referred to family members, friends, and other parents as sources of ECAP information, as well as healthcare professionals (HCPs), particularly pediatricians. Parents said that they exchanged experiences and practices with their peers, while relying on HCPs for guidance on decision-making. When searching for information online, they infrequently recalled the sources used and were rarely aware of providers of "good" health information. While parents often reported trying to identify the authors of information to appraise its reliability, they said they did not undertake more comprehensive information quality checks. The choice and presentation of ECAP information was frequently criticized by all parent groups; in particular, parents of at-risk children or with a manifested allergy were often dissatisfied with HCP consultations, and hence did not straightforwardly apply advice. Though many trusted their HCPs, parents often reported taking preventive measures based on their own intuition. Conclusion: One suggestion to react upon the many criticisms expressed by parents regarding who and how provides ECAP information is to integrate central ECAP recommendations into regular child care counseling by HCPs-provided that feasible ways for doing so are identified. This would assist disease prevention, as parents without specific concerns are often unaware of the ECAP dimension of issues such as nutrition.

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

Background and aims: With an increasing number of Clinical Practice Guidelines (CPGs) addressing primary prevention of food allergy and atopic dermatitis, it is timely to undertake a comprehensive assessment of the quality and consistency of recommendations and evaluation of their implementability in different geographical settings. Methods: We systematically reviewed CPGs from 8 international databases and extensive website searches. Seven reviewers screened records in any language and then used the AGREE II and AGREE REX instruments to critically appraise CPGs published between January 2011 and April 2022. Results: Our search identified 2138 relevant articles, of which 30 CPGs were eventually included. Eight (27%) CPGs were shortlisted based on our predefined quality criteria of achieving scores >70% in the "Scope and Purpose" and "Rigour of Development" domains of the AGREE II instrument. Among the shortlisted CPGs, scores on the "Applicability" domain were generally low, and only 3 CPGs rated highly in the "Implementability" domain of AGREE-REX, suggesting that the majority of CPGs fared poorly on global applicability. Recommendations on maternal diet and complementary feeding in infants were mostly consistent, but recommendations on use of hydrolysed formula and supplements varied considerably. Conclusion: The overall quality of a CPG for Food Allergy and Atopic Dermatitis prevention did not correlate well with its global applicability. It is imperative that CPG developers consider stakeholders' preferences, local applicability, and adapt existing recommendations to each individual population and healthcare system to ensure successful implementation. There is a need for development of high-quality CPGs for allergy prevention outside of North America and Europe. PROSPERO registration number: CRD42021265689.

Food allergy risks and dining industry - an assessment and a path forward.

Food allergies have increased in prevalence over the last few decades and continue to grow. Consumption of even trace amounts of common foods can cause a rapid allergic reaction (generally within minutes) which can be mild to severe to even life-threatening. Eating at restaurants poses a risk of allergic reactions for those with food allergies due to inadequate, inconsistent labeling of allergens in foods. Here, we review food labeling rules and practices in the restaurant industry and compare and contrast it with food labeling for prepackaged foods. We review global and United States trends, and provide a brief historical overview. The paper describes the key legal and economic motivations behind restaurant food labeling. Next, we describe novel risk-driven policies and new biotechnologies that have the potential to change food labeling practices worldwide. Finally, we outline desirable federal regulations and voluntary information disclosures that would positively impact the public health aspects of restaurant food labeling and improve the quality of life for people with severe food allergies.

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

BACKGROUND: Only rigorously prepared analyses can provide the highest level of evidence to inform decision-making. Several recent systematic reviews (SRs) examined the hypothesis that the early introduction of specific allergenic complementary foods (CFs) to infants may lead to a lower incidence of one or more allergic outcomes. However, the methodological rigour and quality of reporting of SRs in this area has not yet been systematically evaluated. METHODS: We comprehensively searched PubMed, Medline (Ovid), and Web of Science Core Collection on 13th January 2022, using a pre-specified and tested search syntax for SRs with RCT evidence on the early introduction of allergenic CFs as a means for allergy prevention in infants and children. We examined the quality and risk of bias (RoB) using AMSTAR-2 and ROBIS tools, examined adherence to the Preferred Reporting Items for SRs and Meta-Analyses (PRISMA), and checked whether certainty of the evidence was assessed. RESULTS: Twelve SRs were included. Application of both tools resulted in similar overall judgements in terms of direction and extent for nine of the 12 SRs. Nine SRs were found to be of critically low to low quality according to AMSTAR-2 and to be at high RoB according to ROBIS. One SR received a moderate quality rating (AMSTAR-2) and high RoB rating (ROBIS). However, for two SRs, judgements between AMSTAR-2 and ROBIS were at stark variance. Only two SRs fully adhered to the PRISMA checklist. Six SRs evaluated the certainty of the body of RCT evidence. Several SRs failed to consider unpublished studies either by an explicit a priori exclusion or by inadequate search strategies. CONCLUSIONS: Well-conducted SRs are important for decision-making and informing guideline development, the quality of their methodology should therefore be considered. The methodological rigour and the reporting quality of SRs on the timing of CF for allergy prevention must be improved. REGISTRATION: https://osf.io/7cs4b .

TreEAT trial: Protocol for a randomized controlled trial investigating the efficacy and safety of early introduction of tree nuts for the prevention of tree nut allergy in infants with peanut allergy.

INTRODUCTION: Children with peanut allergy are at increased risk of developing tree nut allergies, which can be severe and for most lifelong. Introduction of peanut in the first year of life can reduce the risk of peanut allergy; however, prevention strategies for tree nut allergies have not been established. We aimed to test the efficacy and safety of a novel strategy, a supervised multi-nut oral food challenge (OFC) compared with standard care for tree nut allergy prevention in infants at high risk of developing tree nut allergy, TreEAT. METHODS AND ANALYSIS: TreEAT is a 2-armed, open-label, randomized, controlled trial (RCT). Infants (n = 212) aged 4-11 months with peanut allergy will be randomized 1:1 at peanut allergy diagnosis to either a hospital-based multi-tree nut (almond, cashew, hazelnut, and walnut) OFC using multi-nut butter or standard care (home introduction of individual tree nuts). All infants will be assessed at age 18 months, with questionnaires and SPT to peanut and tree nuts. Peanut and tree nut OFCs will be performed as required to determine the allergy status for each nut. The primary outcome is tree nut allergy at age 18 months. Secondary outcomes include peanut allergy resolution, proportion, and severity of adverse events related to tree nut ingestion, number and frequency of tree nuts ingested, quality of life and parental anxiety, and allergy-related healthcare visits from randomization to 18 months of age. Analyses will be performed on an intention-to-treat basis. ETHICS AND DISSEMINATION: TreEAT was approved by the Royal Children's Hospital Human Research Ethics Committee (#70489). Outcomes will be presented at scientific conferences and disseminated through publication. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov ID: NCT04801823.