International Peanut Allergy Prevention, 6 Years After the Learning Early About Peanut Study

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.

Decisions With Patients, Not for Patients: Shared Decision-Making in Allergy and Immunology

Shared decision-making (SDM) is an increasingly implemented patient-centered approach to navigating patient preferences regarding diagnostic and treatment options and supported decision-making. This therapeutic approach prioritizes the patient's perspectives, considering current medical evidence to provide a balanced approach to clinical scenarios. In light of numerous recent guideline recommendations that are conditional in nature and are clinical scenarios defined by preference-sensitive care options, there is a tremendous opportunity for SDM and validated decision aids. Despite the expansion of the literature on SDM, formal acceptance among clinicians remains inconsistent. Surprisingly, a significant disparity exists between clinicians' self-reported adherence to SDM principles and patients' perceptions of its implementation during clinical encounters. This discrepancy underscores a fundamental issue in the delivery of health care, where clinicians may overestimate their integration of SDM, while patients' experiences suggest otherwise. This review critically examines the factors contributing to this inconsistency, including barriers within the health care system, clinician attitudes and behaviors, and patient expectations and preferences. By elucidating these factors in the fields of food allergy, asthma, eosinophilic esophagitis, and other allergic diseases, this review aims to provide insights into bridging the gap between clinician perception and patient experience in SDM. Addressing this discordance is crucial for advancing patient-centered care and ensuring that SDM is not merely a theoretical concept but a tangible reality in the.

Follow-up to Adolescence after Early Peanut Introduction for Allergy Prevention

BACKGROUND

A randomized trial demonstrated consumption of peanut from infancy to age 5 years prevented the development of peanut allergy. An extension of that trial demonstrated the effect persisted after 1 year of peanut avoidance. This follow-up trial examined the durability of peanut tolerance at age 144 months after years of ad libitum peanut consumption.

METHODS

Participants from a randomized peanut consumption trial were assessed for peanut allergy following an extended period of eating or avoiding peanuts as desired. The primary end point was the rate of peanut allergy at age 144 months.

RESULTS

We enrolled 508 of the original 640 participants (79.4%); 497 had complete primary end point data. At age 144 months, peanut allergy remained significantly more prevalent in participants in the original peanut avoidance group than in the original peanut consumption group (15.4% [38 of 246 participants] vs. 4.4% [11 of 251 participants]; P<0.001). Participants in both groups reported avoiding peanuts for prolonged periods of time between 72 and 144 months. Participants at 144 months in the peanut consumption group had levels of Ara h2-specific immunoglobulin E (a peanut allergen associated with anaphylaxis) of 0.03 ± 3.42 kU/l and levels of peanut-specific immunoglobulin G4 of 535.5 ± 4.98 μg/l, whereas participants in the peanut avoidance group had levels of Ara h2-specific immunoglobulin E of 0.06 ± 11.21 kU/l and levels of peanut-specific immunoglobulin G4 of 209.3 ± 3.84 μg/l. Adverse events were uncommon, and the majority were related to the food challenge.

CONCLUSIONS

Peanut consumption, starting in infancy and continuing to age 5 years, provided lasting tolerance to peanut into adolescence irrespective of subsequent peanut consumption, demonstrating that long-term prevention and tolerance can be achieved in food allergy. (Funded by the National Institute of Allergy and Infectious Diseases and others; ITN070AD, ClinicalTrials.gov number, NCT03546413.).

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.

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.

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.

Provision of Food Allergy Care in the United Kingdom and United States: Current Issues and Future Directions

Food allergy (FA) is a growing issue worldwide. The United Kingdom and United States are high-income, industrialized countries with reported increases in FA prevalence over the past few decades. This review compares delivery of FA care in the United Kingdom and United States and each country's response to the heightened demand and disparities for FA services. In the United Kingdom, allergy specialists are scarce and general practitioners (GPs) provide most allergy care. Whereas the United States has more allergists per capita than the United Kingdom, there is still a shortage of allergy services owing to the greater reliance on specialist care for FA in America and wide geographic variation in access to allergist services. Currently, generalists in these countries lack the specialty training and equipment to diagnose and manage FA optimally. Moving forward, the United Kingdom aims to enhance training for GPs so they may provide better quality frontline allergy care. In addition, the United Kingdom is implementing a new tier of semi-specialized GPs and increasing cross-center collaboration through clinical networks. The United Kingdom and United States aim to increase the number of FA specialists, which is critical at a time of rapidly expanding management options for allergic and immunologic diseases requiring clinical expertise and shared decision-making to select appropriate therapies. While these countries aim to grow their supply of quality FA services actively, further efforts to build clinical networks and perhaps recruit international medical graduates and expand telehealth services are necessary to reduce disparities in access to care. For the United Kingdom in particular, increasing quality services will require additional support from the leadership of the centralized National Health Service, which remains challenging.

Shared decision-making, communicating risk, and food allergy in 2023

Background

Across the practice of allergy and clinical immunology, disruptive innovations have accelerated the adoption of shared decision-making (SDM) to improve the health of patients and populations, particularly with regard to food allergy prevention and management of food allergy and anaphylaxis.

Methods

A narrative review was performed to describe recent innovations in shared decision-making, risk communication, and food allergy.

Results

Several challenges, primarily related to the coronavirus disease 2019 (COVID-19) pandemic and misinformation campaigns, have catalyzed adaptations to evolve clinical care. Recent pressures have facilitated the rapid adoption of telemedicine. In 2023, many allergist/immunologists routinely incorporate both in-person and virtual visits to contextually deliver value-based care to each patient. SDM may occur in a hybrid model that incorporates both in-person and virtual encounters, with many patients experiencing benefit from a combination approach. This may be facilitated by leveraging previsit web-based SDM tools. Whether in person or by telemedicine, effective risk communication to avoid cognitive overload while appreciating population variation in numeracy is key to competent implementation of SDM. Misinformation continues to disproportionately harm patients who belong to groups that encourage denial of evidence-based medical recommendations and COVID-19 vaccination intent correlating with sociopolitical factors. Still, strategies to address misinformation that leverage empathy, respect, and expertise can help to mitigate these effects. Physician wellness is a key component to realization of the Quadruple Aim of health care, and the use of positive framing and appreciative inquiry can help to optimize outcomes and improve value in health care.

Conclusion

SDM is an important component to consider when incorporating recent innovations in allergy and clinical immunology care, particularly in the setting of contextual and conditional medical recommendations. Effective risk communication is critical to SDM that is truly reflective of patient goals and preferences, and can be facilitated through in-person encounters, telemedicine, and hybrid models. It is important to foster physician wellness as a component of the Quadruple Aim, particularly in the recent pandemic climate of misinformation and denial of evidence-based medicine within large groups of society.

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.

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.

Value-Based, Cost-Effective Care: The Role of the Allergist-Immunologist

Asthma and allergic disease impact millions of patients and are associated with high costs. Up to 30% of all medical care involves wasted spending. Across the spectrum of care provided by the allergist-immunologist, there are opportunities to improve value and reduce medical waste. Several examples highlight this reality. Evidence suggests that most patients may receive cost-effective care in the management of chronic spontaneous urticaria without the need for laboratory testing. For patients with asthma, although a single maintenance and reliever therapy approach may be cost-effective, insurance-mandated therapy changes are not, and may harm patients. Biologics may be very effective in improving asthma control but are too expensive for this indication-as demonstrated by cost-effectiveness analyses and highlighted by the Institute of Clinical and Economic Review, which concluded that the value-based price for asthma biologics ranges between $6500 and 14,3000 per year. Early introduction may prevent food allergy, but screening before first introduction is neither necessary nor cost-effective, although early salvage food oral immunotherapy may result in improved quality of life and cost savings. Evidence does not support the presence of allergic disease as a risk factor for anaphylaxis to coronavirus disease 2019 vaccination, and risk-stratified vaccination approaches do not appear cost-effective. Allergen immunotherapy is a very cost-effective treatment option. The practice of allergy-immunology has continued to evolve in recent years and can provide a leading example of high-value practice.

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.

Real-World LEAP Implementation

PURPOSE OF REVIEW

In 2015, findings from the Learning Early About Peanut allergy (LEAP) trial provided the first convincing evidence that peanut allergy may be preventable through early peanut introduction into the infant diet. Here we discuss implementation of the LEAP study findings around the world and emerging evidence of the impacts on infant feeding and food allergy.

RECENT FINDINGS

The LEAP findings led to rapid changes in allergy prevention guidelines internationally to recommend early peanut introduction. There is now emerging evidence that this has been followed by a substantial increase in early peanut introduction to infants. Studies investigating the impact of these changes in infant feeding practices on the prevalence of peanut allergy are underway. The LEAP trial represented a significant step forwards in food allergy prevention and new research over the past 5 years has provided insights into how best to implement this intervention in the real world.