Food-induced fatal anaphylaxis: From epidemiological data to general prevention strategies

Food-triggered anaphylaxis in adults

PURPOSE OF REVIEW

Adult food allergy, either unresolved from childhood, or new-onset in adult-life, is known to be increasingly prevalent. Although much of the reported anaphylaxis in adults is due to drug reactions, foods are becoming an increasingly important trigger, affecting adults of all ages, with a wide variation in food triggers which are often quite different to those reported in children.

RECENT FINDINGS

Peanuts are well known to cause anaphylaxis in some adult populations, but other legumes such as soy may be more relevant in others. Reactions to natto, fermented soybeans, are currently mainly reported in Japan, but changing dietary practices and an increase in plant-based eating mean natto, other forms of soy and other legumes are increasingly linked to anaphylaxis in Western countries. Anaphylaxis to red meat, caused by sensitization to galactose-α-1,3-galactose and first reported in North America, is now a more world-wide concern. Co-factor induced anaphylaxis is increasingly associated with both wheat allergy and lipid transfer protein allergy.

SUMMARY

More research is urgently needed to characterize adult food allergy, its triggers and symptom severity. Unusual food triggers and potential co-factors should be considered, so that anaphylaxis in adults can be correctly managed, not merely labelled as idiopathic.

Nutritional Considerations of Plant-Based Diets for People With Food Allergy

Plant-based diets (PBD) have been reported throughout history, but are increasingly common in current times, likely in part due to considerable emphasis on climate change and human health and wellness. Many dietary organisations around the world endorse well-planned, nutritionally adequate PBD, which exclude some or all forms of animal-based foods. However, special attention must be given to patients who follow PBD and also have food allergy (FA), as avoidance may increase the risk of developing nutritional deficiencies, including poor growth in children, weight loss in adults and vitamin and mineral deficiencies. Given the increasing prevalence of both PBD and food allergen avoidance diets, healthcare providers are likely to counsel patients with FA who also follow a PBD. In this review, an overview of PBD in patients with FA is provided, including recent trends, macro- and micronutrient needs, and growth for children and weight gain considerations for adults. With regard to a PBD, special attention should be given to ensure adequate fat and protein intake and improving the bioavailability of several minerals such as iron, zinc, iodine, calcium and magnesium, and vitamins such as A, B2, B12 and D. Although the collective data on growth amongst children following a PBD are varied in outcome and may be influenced in part by the type of PBD, growth must be regularly monitored and in adults weight gain assessed as part of any clinical assessment in those people with FA.

Current perspective on allergen immunotherapy for food allergies

Food allergies are an increasing global problem and societal issue. In addition to the potential for severe allergic reactions from accidental ingestion, food allergies impose a significant burden on the quality of life, nutrition, cost of living, and social activities of both those afflicted and their caregivers. Strict avoidance of allergens and use of emergency medications to treat allergic reactions are the traditional management and treatment strategies; however, significant progress has been made in recent years toward better treatment of food allergies. Many clinical trials on food allergen immunotherapy (oral, epicutaneous, and sublingual) have revealed its efficacy in increasing reaction thresholds and desensitization. These positive results led to the first FDA approval of peanut oral immunotherapy (OIT). However, safer and more effective approaches are required, and adjunct treatments and allergen modifications are being considered. More than 100 facilities in Japan conduct OIT, and numerous studies on it have been reported. Unlike in Europe and the US, stepwise oral food challenges with dietary guidance are conducted separately from the OIT. This review describes the current perspectives on allergen immunotherapy for the treatment of food allergies, focusing on evidence from Japan.

Hospitalizations for Food-Induced Anaphylaxis Between 2016 and 2021: Population-Based Epidemiologic Study

BACKGROUND

Food-induced anaphylaxis (FIA) is a major public health problem resulting in serious clinical complications, emergency department visits, hospitalization, and death.

OBJECTIVE

This study aims to assess the epidemiology and the trends in hospitalizations because of FIA in Spain between 2016 and 2021.

METHODS

An observational descriptive study was conducted using data from the Spanish National Hospital discharge database. Information was coded based on the International Classification of Diseases, Tenth Revision. The study population was analyzed by gender and age group and according to food triggers, clinical characteristics, admission to the intensive care unit, severity, and in-hospital mortality. The annual incidence of hospitalizations because of FIA per 100,000 person-years was estimated and analyzed using Poisson regression models. Multivariable logistic regression models were constructed to identify which variables were associated with severe FIA.

RESULTS

A total of 2161 hospital admissions for FIA were recorded in Spain from 2016 to 2021. The overall incidence rate was 0.77 cases per 100,000 person-years. The highest incidence was found in those aged <15 years (3.68), with lower figures among those aged 15 to 59 years (0.25) and ≥60 years (0.29). Poisson regression showed a significant increase in incidence from 2016 to 2021 only among children (3.78 per 100,000 person-years vs 5.02 per 100,000 person-years; P=.04). The most frequent food triggers were "milk and dairy products" (419/2161, 19.39% of cases) and "peanuts or tree nuts and seeds" (409/2161, 18.93%). Of the 2161 patients, 256 (11.85%) were hospitalized because FIA required admission to the intensive care unit, and 11 (0.51%) patients died in the hospital. Among children, the most severe cases of FIA appeared in patients aged 0 to 4 years (40/99, 40%). Among adults, 69.4% (111/160) of cases occurred in those aged 15 to 59 years. Multivariable logistic regression showed the variables associated with severe FIA to be age 15 to 59 years (odds ratio 5.1, 95% CI 3.11-8.36), age ≥60 years (odds ratio 3.87, 95% CI 1.99-7.53), and asthma (odds ratio 1.71,95% CI 1.12-2.58).

CONCLUSIONS

In Spain, the incidence of hospitalization because of FIA increased slightly, although the only significant increase (P=.04) was among children. Even if in-hospital mortality remains low and stable, the proportion of severe cases is high and has not improved from 2016 to 2021, with older age and asthma being risk factors for severity. Surveillance must be improved, and preventive strategies must be implemented to reduce the burden of FIA.

The ambiguous relationship between food and health across the centuries

Since the Palaeolithic Age food has been closely linked to the development of the human species, meeting our energy needs and fuelling our cell metabolism. Without food there can be no life. However, over the centuries food and our eating habits have also had a damaging effect, whether through deficiencies, excesses, direct toxic effects or as a vector of pathogenic agents. The human species has known two major food revolutions: one at the start of the Neolithic Age and the other very recently in the years following the Second World War. In this article we will be looking at the ambiguous relationship between food and human health as well as the health of our planet.

Baked milk and egg diets revisited

Most children with milk and egg allergy are nonreactive to modified forms of milk and egg in bakery products such as muffins because of conformational changes in proteins. These baked milk (BM) and baked egg (BE) diets have become commonplace in the management of milk and egg allergy, respectively. Current laboratory- and skin test-based diagnostic approaches remain limited in their ability to predict BM/BE tolerance, resulting in various approaches to introduce these foods. One approach to introduce BM/BE is to offer a medically supervised oral food challenge and then advise dietary introduction of baked products for children who have tolerance. Another approach is adapted from a home-based protocol of graded ingestion of BM or BE originally intended for non-IgE mediated allergy, often referred to as a "ladder." The ladder advises home ingestion of increasing amounts of BM or BE. For children who have allergy to BM or BE, the ladder is essentially oral immunotherapy, although not always labeled or recognized as such. Risk assessment and education of patients suitable for home introduction are essential. A home approach that may be called a ladder can also be used to escalate diets after demonstrated tolerance of baked forms by introducing lesser cooked forms of milk or egg after tolerating BM or BE. A randomized controlled trial provided clear evidence that baked diets can hasten the resolution of IgE-mediated milk allergy. Moreover, BM/BE foods have an emerging role in the treatment of non-IgE-mediated allergy. There is tangential evidence for BM and BE diets in the prevention of IgE-mediated allergy.

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.

How Intuitive Is the Administration of Pediatric Emergency Medication Devices for Parents? Objective Observation and Subjective Self-Assessment

BACKGROUND

to assess the intuitiveness of parents' administration of pediatric emergency devices (inhalation, rectal, buccal, nasal, and auto-injector).

METHODS

We invited parents without prior experience to administer the five devices to dummy dolls. We observed whether the parents chose the correct administration route and subsequently performed the correct administration procedures without clinically relevant errors. We interviewed parents for their self-assessment of their own administration performance and willingness to administer devices in actual emergencies.

RESULTS

The correct administration route was best for the inhalation device (81/84, 96% of parents) and worst for the intranasal device (25/126, 20%). The correct administration procedures were best for the buccal device (63/98, 64%) and worst for the auto-injector device (0/93, 0%). Their own administration performance was rated to be best by parents for the inhalation device (59/84, 70%) and worst for the auto-injector device (17/93, 18%). The self-assessment of the correct administration overestimated the correct administration procedures for all the devices except the buccal one. Most parents were willing to administer the inhalation device in an emergency (67/94, 79%), while the fewest were willing to administration procedures the auto-injector device (28/93, 30%).

CONCLUSIONS

Intuitiveness concerning the correct administration route and the subsequent correct administration procedures have to be improved for all the devices examined. The parents mostly overestimated their performance. Willingness to use a device in an actual emergency depended on the device.

Anaphylaxis: A 2023 practice parameter update

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

Electrochemically assisted DNA and thioaromatic assembly as sensing and antifouling interface for food allergens

Food allergies have become a global issue and are estimated to affect approximately 220 million people worldwide. Allergy to peanuts can easily become life-threatening and induce anaphylactic reactions. Mislabeling and cross-contamination during food processing can occur in the frame of world population growth and pose a serious health issue. As the mandatory allergen list is not uniform worldwide, the development of routine analytical strategies with high specificity and sensitivity is a demanding task to aid in the rapid identification of allergenic foods. In this work, an electrochemical aptasensor for Ara h1 peanut allergen was developed by immobilizing the specific aptamer by the inserting method. First, a layer of p-aminothiophenol (p-ATP) was immobilized on the gold surface of screen-printed electrodes (GSPE) to improve the aptamer insertion and reduce the fouling effects at the electrode surface. The grafting of the p-ATP and Ara h1 aptamer on the GSPE surface was monitored by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The resulting disposable aptasensor allowed for indirect electrochemical detection of Ara h1 protein in the presence of 5 mM ferro/ferricyanide as a redox probe. The electrochemical response upon aptamer-target interaction was monitored in the concentration range 1-250 nM, and two limits of detection in the nanomolar range were estimated based on DPV (2.78 nM Ara h1) and EIS (0.82 nM Ara h1) measurements. The aptasensor was successfully applied to real sample analysis.

Fatal and Near-Fatal Anaphylaxis: Data From the European Anaphylaxis Registry and National Health Statistics

BACKGROUND

Anaphylaxis is a serious systemic reaction-data on fatal and near-fatal reactions are limited.

OBJECTIVE

To better understand clinical patterns and risks factors of severe anaphylaxis by a deep analysis of data from fatal and near-fatal anaphylaxis.

METHODS

Data from the European Anaphylaxis Registry on fatal/near-fatal anaphylactic reactions and national data on anaphylaxis fatalities were investigated.

RESULTS

A total of 305 fatal/near-fatal reactions among children and adults including 35 fatalities from the European Anaphylaxis Registry were identified. The most frequent elicitors were drugs, insects, and food. Male patients (66%/60%) were more frequently affected. Male sex, higher age, concomitant mastocytosis, and cardiovascular disease were associated with a more severe outcome. With increasing reaction severity, skin symptoms were less frequently observed (45% of fatal reactions). In parallel, anaphylaxis mortality rates were studied. The data show that anaphylaxis mortality rates increased in Germany from 0.48 (2009) to 0.59 per 1,000,000 population per year (2020). This increase was apparent only in the female population. In this data set, drugs were the most frequent elicitor of anaphylaxis fatalities, and the rate for this increased over time.

CONCLUSIONS

We identified not only elicitors but also individual factors to be associated with an increased risk of fatal anaphylaxis. Such patients should be recognized and managed with great caution. The increase in drug-induced fatalities points to the need for a better allergological care of patients suffering from drug hypersensitivity.

Approach to Idiopathic Anaphylaxis in Adolescents

Anaphylaxis is a potentially-life threatening condition. Adolescents are particularly vulnerable due to increased risk-taking behaviors, poor disease management, and minimized perception of risk. Although most anaphylaxis can be attributed to food, drug, or venom allergy via a detailed history and confirmatory studies, in nearly 1 in 5 cases, the cause may not be obvious. Clinical differentials including rare allergens, cofactors, mast-cell disorders, and mimic disorders can increase the likelihood of discovering of the cause of anaphylaxis.

Widespread monoclonal IgE antibody convergence to an immunodominant, proanaphylactic Ara h 2 epitope in peanut allergy

BACKGROUND

Despite their central role in peanut allergy, human monoclonal IgE antibodies have eluded characterization.

OBJECTIVE

We sought to define the sequences, affinities, clonality, and functional properties of human monoclonal IgE antibodies in peanut allergy.

METHODS

We applied our single-cell RNA sequencing-based SEQ SIFTER discovery platform to samples from allergic individuals who varied by age, sex, ethnicity, and geographic location in order to understand commonalities in the human IgE response to peanut allergens. Select antibodies were then recombinantly expressed and characterized for their allergen and epitope specificity, affinity, and functional properties.

RESULTS

We found striking convergent evolution of IgE monoclonal antibodies (mAbs) from several clonal families comprising both memory B cells and plasmablasts. These antibodies bound with subnanomolar affinity to the immunodominant peanut allergen Ara h 2, specifically a linear, repetitive motif. Further characterization of these mAbs revealed their ability to single-handedly cause affinity-dependent degranulation of human mast cells and systemic anaphylaxis on peanut allergen challenge in humanized mice. Finally, we demonstrated that these mAbs, reengineered as IgGs, inhibit significant, but variable, amounts of Ara h 2- and peanut-mediated degranulation of mast cells sensitized with allergic plasma.

CONCLUSIONS

Convergent evolution of IgE mAbs in peanut allergy is a common phenomenon that can reveal immunodominant epitopes on major allergenic proteins. Understanding the functional properties of these molecules is key to developing therapeutics, such as competitive IgG inhibitors, that are able to stoichiometrically outcompete endogenous IgE for allergen and thereby prevent allergic cascade in cases of accidental allergen exposure.

Immune signatures predicting the clinical outcome of peanut oral immunotherapy: where we stand

Peanut allergy is a growing health concern that can cause mild to severe anaphylaxis as well as reduced quality of life in patients and their families. Oral immunotherapy is an important therapeutic intervention that aims to reshape the immune system toward a higher threshold dose reactivity and sustained unresponsiveness in some patients. From an immunological point of view, young patients, especially those under 3 years old, seem to have the best chance for therapy success. To date, surrogate markers for therapy duration and response are evasive. We provide a comprehensive overview of the current literature state regarding immune signatures evolving over the course of oral immunotherapy as well as baseline immune conditions prior to the initiation of treatment. Although research comparing clinical and immune traits in the first years of life vs. later stages across different age groups is limited, promising insights are available on immunological endotypes among peanut-allergic patients. The available data call for continued research to fill in gaps in knowledge, possibly in an integrated manner, to design novel precision health approaches for advanced therapeutic interventions in peanut allergy.

Epidemiology of anaphylaxis: is the trend still going up?

PURPOSE OF REVIEW

To understand the current global scale of anaphylaxis and identify possible strategies to increase the accuracy of epidemiological data.

RECENT FINDINGS

Anaphylaxis mortality and morbidity statistics may gain new perspectives with the global implementation of the ICD-11. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk, and support decision-making to facilitate health care planning and implementation of public health measures to prevent anaphylaxis.

SUMMARY

The true rate of anaphylaxis is unknown due to a number of factors, such as misdiagnosis, miscoding and undernotification. Moreover, there is lack of information about anaphylaxis epidemiology in many countries. Difficulties on collecting accurate and comparable data should be acknowledged and anaphylaxis data can vary widely. Currently, most robust data are derived from hospitalization datasets and national mortality databases. Anaphylaxis accounts for up to 0.26% of overall hospital admissions. It is suggested that the number of hospital admissions for anaphylaxis is increasing in many countries, both with respect to all-causes of anaphylaxis and by trigger, but the mortality rate remains low. However, there are still great challenges in capturing quality anaphylaxis mortality and morbidity statistics. Better understanding of anaphylaxis trends should clarify some areas of uncertainty about risk factors and prospect effective prevention strategies. As the knowledge derived from populations is key information for more realistic decision-making, the construction of the new section addressed to anaphylaxis in the ICD-11 will allow the collection of more accurate epidemiological data to support high quality management of patients, and to better facilitate health care planning to implement public health measures, reduce the morbidity and mortality attributable to anaphylaxis.

Mast Cells and Basophils in IgE-Independent Anaphylaxis

Anaphylaxis is a life-threatening or even fatal systemic hypersensitivity reaction. The incidence of anaphylaxis has risen at an alarming rate in the past decades in the majority of countries. Generally, the most common causes of severe or fatal anaphylaxis are medication, foods and Hymenoptera venoms. Anaphylactic reactions are characterized by the activation of mast cells and basophils and the release of mediators. These cells express a variety of receptors that enable them to respond to a wide range of stimulants. Most studies of anaphylaxis focus on IgE-dependent reactions. The mast cell has long been regarded as the main effector cell involved in IgE-mediated anaphylaxis. This paper reviews IgE-independent anaphylaxis, with special emphasis on mast cells, basophils, anaphylactic mediators, risk factors, triggers, and management.

Prevalence of Parent-Reported Food Allergy in a Mexican Pre-School Population

The magnitude and relevance of food allergies in the preschool population remain unknown in most regions of Mexico and Latin America. Thus, our aim was to estimate the parent-reported prevalence of food allergies in a Mexican preschool population and to characterize their clinical diagnosis and presentation. A cross-sectional survey was conducted in Culiacán City. A validated questionnaire was utilized. A total of 810 parents responded to the questionnaire (valid response rate, 40.7%). The estimated prevalence rates (95% CI) were: "physician-diagnosed Food Allergy (FA), ever" 5.30% (3.86-7.08); "immediate-type FA, ever" 2.96% (1.91-4.38); "immediate-type FA, current" 1.60% (0.86-2.73); and food-dependent anaphylaxis 1.11% (0.51-2.01). The main food allergens were milk (0.49%), strawberries (0.37%), egg, and soy (0.25% each). Atopic diseases and a family history of allergies were significantly associated with immediate-type FA. Among "immediate-type FA, current" cases, 76.9% required emergency room visits, but the prescription of epinephrine autoinjectors was reported in one case only. The food reactions occurred at home (92.35%), in a relative's house (38.5), and at restaurants (23%). Immediate-type FA reactions requiring emergency room visits are not uncommon among the studied population. Actions like proper anaphylaxis management and the prevention of cross-contamination of foods should be encouraged.

Severe Anaphylactic Reactions to Home Doses of Oral Immunotherapy for Food Allergy

BACKGROUND

Severe anaphylactic reactions to home doses may occur during food allergy oral immunotherapy (OIT).

OBJECTIVE

To study the rate and risk factors for such reactions.

METHODS

We studied all patients aged greater than 3.5 years who completed OIT in a single center between April 2010 and January 2020. All home epinephrine-treated reactions (HETRs) were identified. High-grade HETRs (HG-HETRs) were defined as HETRs involving respiratory (SpO2 of 94% or less), cardiovascular (low blood pressure), or central nervous system impairment (loss of consciousness). We investigated the rate and risk factors for HG-HETRs.

RESULTS

A total of 1,637 OIT treatments were studied: milk (880), peanut (346), tree nuts (221), sesame (115), and egg (75). Of 390 identified HETRs, 30 HG-HETRs occurred during 27 treatments (1.65% of all treatments). Nearly all (26 of 30) were during milk OIT in patients with house dust mite (HDM) sensitization and asthma (26 of 30 each). Of the 30 patients with HG-HETRs, 21 recovered with one or two epinephrine treatments, but nine (0.55% of all treatments) did not respond to a second dose of epinephrine and were deemed to have refractory anaphylaxis. Three patients required intensive care unit admission and three received epinephrine drip, but none required ventilatory support. Risk factors for HG-HETRs included milk OIT (P = .031), asthma (P = .02) and HDM sensitization (P = .02). No specific triggers for HG-HETR were identified. Of patients with HG-HETRs, 25.9% were fully desensitized, including the four non-milk treated patients; 22.2% were partially desensitized; and 51.9% failed.

CONCLUSIONS

High-grade HETRs are uncommon, particularly refractory anaphylactic reactions to home OIT doses. Although milk OIT, asthma, and HDM sensitization are the main risk factors for such reactions, identification of patients who are at risk is challenging.

Overview of Allergy and Anaphylaxis

Allergic reactions and anaphylaxis occur on a severity continuum from mild and self-limited to potentially life-threatening or fatal reactions. Anaphylaxis is typically a multiorgan phenomenon involving a broad range of effector cells and mediators. Emergency department visits for anaphylaxis are increasing, especially among children. There is a broad differential diagnosis for anaphylaxis, and the diagnosis of anaphylaxis can be aided by the use of the National Institutes of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network clinical diagnostic criteria. Risk factors for severe anaphylaxis include older age, delayed epinephrine administration, and cardiopulmonary comorbidities.

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.

Viewing Pediatric Food Oral Immunotherapy Through an Ethical Lens-A Narrative Systematic Review

BACKGROUND

Food allergy remains a common problem and a lifelong condition for many children. In recent years, food allergy management has increasingly involved conversations about food oral immunotherapy (OIT). Although ethical considerations of autonomy, beneficence, nonmaleficence, and justice implicitly inform these conversations, applying these principles can be complex, particularly in young children. Families of young children assume a role of surrogate decision-maker and must balance immediate risks with the hope of longer-term benefits.

OBJECTIVE

To explore implementation of OIT in children through an ethical lens.

METHODS

To evaluate OIT through an ethical lens, we conducted a literature search to explore currently published frameworks in this area.

RESULTS

Evaluation of the harm principle, the basic interest principle, and the best interest principle of parental decision-making can be informative. Shared decision-making continues to be central to the process of engaging with patient-family units to individualize the best care, at the right time, and minimize decisional discord. Although OIT is well-positioned to promote health and well-being, challenges to equity, sustainability, and organizational support must be considered to improve access for appropriate patients.

CONCLUSIONS

Whereas approaches to food OIT may be tailored to the individual context of each patient-family unit, ethical principles must guide decisions to initiate and continue therapy. Traditional ethical principles of autonomy, beneficence, nonmaleficence, and justice remain cornerstones when considering the ethical context of OIT.

Are There Hidden Dangers Associated With Milk and Egg Dietary Advancement Therapy?

Dietary advancement therapies (DATs) constitute a continuum spanning extensively heated item ingestion, progressive milk or egg ladders, and oral immunotherapy (OIT). These represent an evolution in food allergy management from strict avoidance to an active therapy that may modulate the immune system to develop tolerance to particular forms of the allergen. Many egg or milk individuals are tolerant to baked egg or milk at baseline, and regular consumption (at home ingestion) of baked milk or egg is a safe process with potential quality of life and immunologic benefit. Milk and egg ladders, developed for non-IgE mediated allergy, are increasingly being adapted to IgE-mediated allergy as a potentially safe at-home option for gradual dietary advancement. However, data are limited regarding how safe and effective these approaches are or what patient is best suited for which DAT. It is also unclear whether extensively heated allergen consumption and ladders are susceptible to the same patient-specific factors that affect day-to-day tolerance and safety in OIT. Several recent events involving near-fatal or fatal reactions to milk or egg products (all among patients with asthma) have highlighted that DATs are not risk-free, and that physician guidance in these therapies is essential. Such guidance may include obtaining informed consent before starting any DAT and instituting the same safe dosing rules for OIT across any form of DAT. This rostrum discusses practical concerns about the safety of DAT, and considerations regarding how clinicians can maximize patient protection while defining the safety and efficacy of real-world implementation of these concepts.

Factors associated with home epinephrine-treated reactions during peanut and tree-nut oral immunotherapy

BACKGROUND

Home reactions requiring epinephrine administration, a marker of their severity, restrict the widespread use of oral immunotherapy (OIT), but their risk factors are largely not known.

OBJECTIVE

To identify risk factors for such reactions during OIT to most allergenic foods.

METHODS

All patients who began OIT for peanut, tree nuts, sesame, or egg allergy at the Shamir Medical Center between April 2010 and January 2020 were enrolled. The patients were instructed to use their epinephrine autoinjectors during reactions consisting of severe abdominal pain, significant shortness of breath, or lethargy, or whenever in uncertainty of reaction severity. Patients with and without home epinephrine-treated reactions (HETRs) were compared.

RESULTS

A total of 757 OIT treatments for peanut (n = 346), tree nuts (n = 221; walnut n = 147, cashew n = 57, hazelnut n = 16, almond n = 1), sesame (n = 115), and egg (n = 75) allergies were administered to 644 patients. Eighty-three (10.9%) patients experienced HETRs. The highest rate of HETRs was experienced during walnut (20.4%) or hazelnut (25%) OIT, followed by peanut (9.8%), sesame (6.1%), egg (6.7%), and cashew (5.3%) OIT. Risk factors for HETRs included a reaction treated in an emergency department (ER) (P = .005) before starting OIT and a reaction treated with epinephrine during in-clinic induction (P < .001). Significantly fewer patients with (73.6%) than without (88.3%) HETRs achieved full desensitization (P = .001), but only a few patients with HETRs (8.4%) failed treatment.

CONCLUSION

Previous reaction severity is the main predictor for HETRs during OIT. These reactions are more frequent during walnut and hazelnut OIT than during OIT for other foods studied. Most patients experiencing HETRs achieved desensitization.

Cow's milk and hen's egg anaphylaxis: A comprehensive data analysis from the European Anaphylaxis Registry

BACKGROUND

Cow's milk (CM) and hen's egg (HE) are leading triggers of anaphylaxis in early childhood. The aim of this study was to identify clinical phenotypes and therapeutic measures for CM anaphylaxis (CMA) compared to HE anaphylaxis (HEA) in children up to 12 years of age, based on a large pan-European dataset from the European Anaphylaxis Registry.

METHODS

Data from 2007 to 2020 on clinical phenotypes and treatment from 10 European countries, as well as Brazil, were analysed. The two-step cluster analysis was used to identify the most frequent phenotypes. For each trigger, three clusters were extracted based on sex, age, and existence of symptoms in four vitally important systems.

RESULTS

Altogether 284 children with CMA and 200 children with HEA were identified. They were characterised as male (69% vs. 64%), infants (65% vs. 61%), with a most frequent grade III of Ring&Messmer classification (62% vs. 64%), in CMA versus HEA, respectively. Respiratory symptoms occurred more often in CMA (91% vs. 83%, p = 0.010), especially in infants (89% vs. 79%, p = 0.008). Cardiovascular symptoms were less frequent in CMA (30% vs. 44%, p = 0.002), in both infants (33% vs. 46%, p = 0.027), and older children (25% vs. 42%, p = 0.021). The clusters extracted in the CMA group were characterised as: (1) mild dermal infants with severe GI (40%), 2. severe dermal (35%), 3. respiratory (25%). While in HEA group: 1. infants with severe GI and/or reduction of alertness (40%), (2) conjunctival (16%), (3) mild GI without conjunctivitis (44%). The severity of the reaction was independent from the amount of ingested allergen protein, regardless of trigger. The first-line adrenaline application differed between the countries (0%-92%, as well as the reasons for not administering adrenaline, p < 0.001).

CONCLUSIONS

Despite the similarity of their age, sex, and severity grade, the clinical profiles differed between the CMA and HEA children. Adrenaline was underused, and its administration was country dependent. Further studies are needed to assess to what extent the differences in the clinical profiles are related to matrix and/or absorption effects, and/or the allergen itself.

Efficacy and safety of food allergy oral immunotherapy in adults

BACKGROUND

Oral immunotherapy (OIT) is an emerging method for treating food allergy in children. However, data regarding adults undergoing this process are lacking.

METHODS

We retrospectively analyzed the medical records of patients with food allergy aged ≥17 years who completed OIT treatment between April 2010 and December 2020 at Shamir Medical Center. Data were compared with that of children aged 4 to <11 years and adolescents aged ≥11 to 17 treated during the same time period.

RESULTS

A total of 96 adults at a median age of 22.3 years who underwent OIT for milk (n = 53), peanut (n = 18), sesame (n = 7), egg (n = 5), and tree nuts (n = 13) were analyzed and compared with 1299 children and 309 adolescents. Adults experienced more adverse reactions requiring injectable epinephrine, both during in-clinic up-dosing (49% vs. 15.9% and 26.5% for children and adolescents, respectively, p < 0.0001) and during home treatment (22.9% vs. 12.4%, p = 0.007 for children, and 17.5%, p = 0.23 for adolescents). Most adults (61.5%) were fully desensitized, but the rates of full desensitization were significantly lower than children (73.4%, p = 0.013). Significantly more adults (28.3%) undergoing milk OIT failed treatment than children (14.3%, p = 0.015) and adolescents (14.1%, p = 0.022), while failure rates in adults undergoing OIT for other foods were low (9.3%) and comparable with children and adolescents.

CONCLUSIONS

OIT is successful in desensitizing most adults with IgE-mediated food allergy. Adults undergoing milk OIT are at increased risk for severe reactions and for OIT failure while failure rates in adults undergoing OIT for other foods are low.

Peanut lipids influence the response of bronchial epithelial cells to the peanut allergens Ara h 1 and Ara h 2 by decreasing barrier permeability

Background: Peanut-allergic individuals react upon their first known ingestion of peanuts, suggesting sensitization occurs through non-oral exposure. Increasing evidence suggests that the respiratory tract is a probable site for sensitization to environmental peanuts. However, the response of the bronchial epithelium to peanut allergens has never been explored. Furthermore, food matrix-derived lipids play an important role in allergic sensitization. Objective: To contribute to a better understanding of the mechanisms of allergic sensitization to peanuts via inhalation, by exploring the direct effect of the major peanut allergens Ara h 1 and Ara h 2 and peanut lipids on bronchial epithelial cells. Methods: Polarized monolayers of the bronchial epithelial cell line 16HBE14o- were stimulated apically with peanut allergens and/or peanut lipids (PNL). Barrier integrity, transport of allergens across the monolayers, and release of mediators were monitored. Results: Ara h 1 and Ara h 2 impacted the barrier integrity of the 16HBE14o- bronchial epithelial cells and crossed the epithelial barrier. Ara h 1 also induced the release of pro-inflammatory mediators. PNL improved the barrier function of the cell monolayers, decreased paracellular permeability and reduced the amount of allergens crossing the epithelial layer. Conclusion: Our study provides evidence of the transport of Ara h 1 and Ara h 2 across the airway epithelium, of the induction of a pro-inflammatory milieu, and identifies an important role for PNL in controlling the amount of allergens that can cross the epithelial barrier. These, all together, contribute to a better understanding of the effects of peanuts exposure on the respiratory tract.

Oral immunotherapy for food allergy: Translation from studies to clinical practice?

Oral immunotherapy (OIT) is now recognized as an alternative active treatment to strict food avoidance in certain patients with IgE-mediated food allergy. Studies have confirmed the efficacy of OIT to desensitize children with allergy to cow's milk, eggs, and peanuts. The benefits, risks, and constraints of OIT are becoming increasingly well understood. However, there is no consensual criteria to select patients to whom OIT could be proposed, and many issues remain to address including the definitions of desensitization and long-term efficacy, the assessment of patient's experience in real life, the optimization of buildup and maintenance protocols, and the utility of multiple food OIT. The recent authorization by medical agency concerning the first medicine for peanut OIT is a step forward towards higher standardization in the practice of OIT. This article summarizes in comprehensive narrative format data on efficacy, tolerance, impact on quality of life and adverse effects of OIT and discuss elements to consider in clinical practice before starting OIT.

Development of sensitization to peanut and storage proteins and relation to markers of airway and systemic inflammation: A 24-year follow-up

BACKGROUND

Long-time data of peanut allergy over time is sparse. We aimed to study the longitudinal development of sensitization to peanut extract and storage protein allergen molecules and associations with asthma status, airway and systemic inflammation markers.

METHODS

The Swedish birth cohort BAMSE followed 4089 participants with questionnaires, clinical investigations and blood sampling between 0 and 24 years. Information on (i) background factors at 2 months, (ii) peanut allergy symptoms and IgE data (ImmunoCAP) at 4, 8, 16, and 24 years, and (iii) IgE to storage proteins, lung function data including exhaled nitric oxide (FENO) as well as systemic inflammatory markers at 24 years of age were collected.

RESULTS

The prevalence of peanut extract sensitization, defined as IgE ≥ 0.35 kU_A /L, was 5.4%, 8.0%, 7.5%, and 6.2% at 4, 8, 16, and 24 years of age, respectively. Between 8 and 24 years of age, (33/1565) participants developed IgE-ab to peanut extract (median 1,4, range 0.7-2.6 kU_A /L), and among those 85% were also sensitized to birch. Only six individuals developed sensitization to Ara h 2 (≥0.1 kU_A /L) between 8 and 24 years of age, of whom three had an IgE-ab level between 0.1-0.12 kU_A /L. Storage protein sensitization was associated with elevated FENO, blood eosinophils and type 2 inflammation-related systemic proteins.

CONCLUSION

Sensitization to peanut extract after 4 years of age is mainly induced by birch cross-sensitization and IgE to Ara h 2 rarely emerges after eight years of age. Storage protein sensitization is associated with respiratory and systemic inflammation.

Direct Versus Indirect Query Performance of ICD-9/-10 Coding to Identify Anaphylaxis

BACKGROUND

Anaphylaxis is an often under =diagnosed, severe allergic event for which epidemiological data are sporadic. Researchers have leveraged administrative and claims data algorithms to study large databases of anaphylactic events; however, little longitudinal data analysis is available after transition to the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM).

OBJECTIVE

Study longitudinal trends in anaphylaxis incidence using direct and indirect query methods.

METHODS

Emergency department (ED) and inpatient data were analyzed from a large state health care administration database from 2011 to 2020. Incidence was calculated using direct queries of anaphylaxis ICD-9-CM and ICD-10-CM codes and indirect queries using a symptom-based ICD-9-CM algorithm and forward mapped ICD-10-CM version to identify undiagnosed anaphylaxis episodes and to assess algorithm performance at the population level.

RESULTS

An average of 2.4 million inpatient and 7.5 million ED observations/y were analyzed. Using the direct query method, annual ED anaphylaxis cases increased steadily from 1,454 (2011) to 4,029 (2019) then declined to 3,341 in 2020 during the coronavirus disease 2019 (COVID-19) pandemic. In contrast, inpatient cases remained relatively steady, with a slight decline after 2015 during the ICD version transition, until a significant drop occurred in 2020. Using the indirect queries, anaphylaxis cases increased markedly after the ICD transition year, especially involving drug-related anaphylaxis.

CONCLUSIONS

Nontypical drug associations with anaphylaxis episodes using the ICD-10-CM version of the algorithm suggest poor performance with drug-related codes. Further, the increased granularity of ICD-10-CM identified potential limitations of a previously validated symptom-based ICD-9-CM algorithm used to detect undiagnosed cases.

Dose and route of administration determine the efficacy of prophylactic immunotherapy for peanut allergy in a Brown Norway rat model

Introduction

Allergen-specific immunotherapy (IT) is emerging as a viable option for treatment of peanut allergy. Yet, prophylactic IT remains unexplored despite early introduction of peanut in infancy was shown to prevent allergy. There is a need to understand how allergens interact with the immune system depending on the route of administration, and how different dosages of allergen may protect from sensitisation and a clinical active allergy. Here we compared peanut allergen delivery via the oral, sublingual (SL), intragastric (IG) and subcutaneous (SC) routes for the prevention of peanut allergy in Brown Norway (BN) rats.

Methods

BN rats were administered PBS or three different doses of peanut protein extract (PPE) via either oral IT (OIT), SLIT, IGIT or SCIT followed by intraperitoneal (IP) injections of PPE to assess the protection from peanut sensitisation. The development of IgE and IgG1 responses to PPE and the major peanut allergens were evaluated by ELISAs. The clinical response to PPE was assessed by an ear swelling test (EST) and proliferation was assessed by stimulating splenocytes with PPE.

Results

Low and medium dose OIT (1 and 10 mg) and all doses of SCIT (1, 10, 100 µg) induced sensitisation to PPE, whereas high dose OIT (100 mg), SLIT (10, 100 or 1000 µg) or IGIT (1, 10 and 100 mg) did not. High dose OIT and SLIT as well as high and medium dose IGIT prevented sensitisation from the following IP injections of PPE and suppressed PPE-specific IgE levels in a dose-dependent manner. Hence, administration of peanut protein via different routes confers different risks for sensitisation and protection from peanut allergy development. Overall, the IgE levels toward the individual major peanut allergens followed the PPE-specific IgE levels.

Discussion

Collectively, this study showed that the preventive effect of allergen-specific IT is determined by the interplay between the specific site of PPE delivery for presentation to the immune system, and the allergen quantity, and that targeting and modulating tolerance mechanisms at specific mucosal sites may be a prophylactic strategy for prevention of peanut allergy.

Disparities in the Diagnosis and Management of Anaphylaxis

PURPOSE OF REVIEW

The goal of this review is to characterize health disparities impacting the recognition and treatment of anaphylaxis.

RECENT FINDINGS

Previous research has identified major health disparities related to atopic conditions including asthma, atopic dermatitis, and food allergies (FA); however, disparities related to anaphylaxis have yet to be examined in depth. We found widespread health disparities in the incidence and severity of anaphylaxis, as well as in the management of allergies (particularly food allergies) that place individuals at risk of anaphylaxis. Sociodemographic factors are associated with numerous negative health outcomes related to anaphylaxis. We highlight several key steps that must be taken to address these disparities.

T-cell epitope discovery and single-cell technologies to advance food allergy research

There is good evidence for a role of T cells in food allergy, but there is a lack of mechanistic understanding and phenotypic markers of the specific T cells contributing to pathology. Recent technologic advancements have allowed for a new experimental paradigm where we can find and pull out rare antigen-specific T cells and characterize them at the single-cell level. However, studies in infectious disease and broader allergy have shown that these techniques benefit greatly from precisely defined T-cell epitopes. Food allergens have fewer epitopes currently available, but it is growing and promises to overcome this gap. With growing use of this experimental design, it will be important to unbiasedly map T-cell phenotypes across food allergy and look for commonalities and contrasts to other allergic and infectious diseases. Once a pathologic phenotype for T cells has been established, the frequencies of these cells can be monitored with simpler techniques that could be applied to the clinic and used in diagnosis, prediction of treatment responsiveness, and discovery of targets for new treatments.

Knowledge gaps in food allergy among the general public in Jeddah, Saudi Arabia: Insights based on the Chicago food allergy research survey

Background

Food allergy is an increasing health concern. Studies have shown that food allergy knowledge is lacking among people, especially in areas related to distinction between food allergy and intolerance, symptoms recognition, and current means of management. This knowledge gap puts allergic patients at more risk of getting fatal anaphylactic reactions, which occur mostly in public areas. Locally, Public's knowledge and attitudes of food allergy was not sufficiently investigated. Therefore, we aim to assess food allergy knowledge and attitudes among Jeddah population in Saudi Arabia.

Methods

We adopted The Chicago Food Allergy Research Survey for the General Public (CFARS-GP) and used it as a data collection tool. We hosted the questionnaire on Google Forms and distributed the link through social media outlets targeting individuals of Jeddah population who are 18 years old and above.

Results

A total of 510 individuals completed the survey. The respondents answered 56% of the knowledge-based items correctly. Knowledge was strongest in symptoms/severity and definition/diagnosis, while it was weakest in susceptibility and prevalence, distinction between food allergy and intolerance, and food allergy management. Higher knowledge was significantly associated with prior training in food allergy, food-allergic acquaintance (i.e., having food allergy or knowing an allergic patient), and being a relative of a health care worker. For the attitudes, respondents thought that food allergy negatively affects patients' quality of life, and that schools should establish policies to protect allergic children; however, they downplayed stigma associated with food allergy.

Conclusion

Increased food allergy knowledge among the general public is needed especially in areas related to susceptibility and prevalence, distinction between food allergy and intolerance, triggers and environmental risks, and the management of food allergy. Prior experience with food allergy through (1) training, (2) food-allergic acquaintance, or (3) being a relative of a health care worker increases food allergy knowledge significantly. Thus, targeted educational interventions might have a significant effect in improving food allergy knowledge among the general population.

Food-specific immunoglobulin A does not correlate with natural tolerance to peanut or egg allergens

ImmunoglobulinA (IgA) is the predominant antibody isotype in the gut, where it regulates commensal flora and neutralizes toxins and pathogens. The function of food-specific IgA in the gut is unknown but is presumed to protect from food allergy. Specifically, it has been hypothesized that food-specific IgA binds ingested allergens and promotes tolerance by immune exclusion; however, the evidence to support this hypothesis is indirect and mixed. Although it is known that healthy adults have peanut-specific IgA in the gut, it is unclear whether children also have gut peanut-specific IgA. We found in a cohort of non-food-allergic infants (n = 112) that there is detectable stool peanut-specific IgA that is similar to adult quantities of gut peanut-specific IgA. To investigate whether this peanut-specific IgA is associated with peanut tolerance, we examined a separate cohort of atopic children (n = 441) and found that gut peanut-specific IgA does not predict protection from development of future peanut allergy in infants nor does it correlate with concurrent oral tolerance of peanut in older children. We observed higher plasma peanut-specific IgA in those with peanut allergy. Similarly, egg white-specific IgA was detectable in infant stools and did not predict egg tolerance or outgrowth of egg allergy. Bead-based epitope assay analysis of gut peanut-specific IgA revealed similar epitope specificity between children with peanut allergy and those without; however, gut peanut-specific IgA and plasma peanut-specific IgE had different epitope specificities. These findings call into question the presumed protective role of food-specific IgA in food allergy.

Food allergy in the World Health Organization's International Classification of Diseases (ICD)-11

There are increasing global data regarding the prevalence of food allergy and food-induced anaphylaxis. However, knowledge in morbidity and mortality epidemiological data is still not optimal, and international comparable standards remain poorly accessed. This information could in turn support better clinical practice and possibly prevent future severe reactions and avoidable fatalities. The International Classification of Diseases (ICD) is the standard diagnostic tool used for epidemiology, health management, and clinical purposes supported by the World Health Organization (WHO). It is also used to determine health care payment and reimbursement of providers and health care services in hospitals. Thanks to the academic and technical efforts under the ALLERGY in ICD-11 initiative the pioneer "Allergy and hypersensitivity conditions" section has been built under the "Disorders of the Immune System" chapter of the ICD-11. The "Food hypersensitivity" (FH) subsection is classified under the "Complex allergic or hypersensitivity conditions" section and "Food-induced anaphylaxis" is under the "Anaphylaxis" section. In order to inform the development of strategies to reduce preventable FHs/food allergies, the burden of disease in different healthcare settings and patient populations and their common etiologies need to be understood. Besides, greater specificity regarding clinical conditions and services delivered will provide payers, policy makers, and providers with better information to make major refinements to countries payment and reimbursement systems, including the design and implementation of pay-for-performance program.The new classification addressed to FHs will enable the collection of more accurate epidemiological data to support quality management of patients with FHs/food allergies, and better facilitate health care planning and decision-making and public health measures to prevent and reduce their morbidity and mortality. The improved logic and standardized definitions through the ICD-11 (and other WHO classifications) will also facilitate international comparisons of quality care and the sharing of best practice globally.

Bronchial hyperresponsiveness and asthma during oral immunotherapy for egg or peanut allergy in children

Background

Bronchial hyperresponsiveness (BHR) and asthma are frequently present in children with food allergy. We assessed BHR in children receiving oral immunotherapy (OIT) for persistent egg or peanut allergy and examined whether OIT affects asthma control.

Methods

Methacholine challenge testing was performed in 89 children with persistent egg or peanut allergy diagnosed by double-blind, placebo-controlled food challenge and 80 control children without food allergy. Of the 89 food-allergic children, 50 started OIT for egg allergy and 39 for peanut allergy. Sensitization to aeroallergens was evaluated by skin prick testing. Forty of the 89 children with regular controller treatment for asthma underwent methacholine challenge testing and 34 measurement of exhaled nitric oxide (FeNO) at baseline and after 6-12 months of OIT.

Results

Methacholine challenge testing revealed significant BHR in 29/50 children (58%) with egg allergy, 15/39 children (38%) with peanut allergy, and 6/80 controls (7.5%). The mean cumulative dose of methacholine causing a 20% fall in FEV1 differed significantly between the egg and peanut-allergic versus the control children (1009 μg, 1104 μg, and 2068 μg, respectively, p < 0.001). Egg or peanut OIT did not affect lung function, the degree of BHR or FeNO levels in children with asthma and had no adverse effect on asthma control. Lung function or BHR did not associate with the OIT outcome.

Conclusion

BHR was significantly more frequent in children with persistent egg or peanut allergy than in children without food allergy. Oral immunotherapy did not increase BHR and was safe for children on regular asthma medication.

Incidence, triggering factors, symptoms, and treatment of anaphylaxis in a pediatric hospital

Objective

Assess the incidence of anaphylaxis in the emergency room (ER) of a private pediatric hospital in the city of São Paulo, Brazil, and describe associated factors.

Method

This was a cross-sectional, retrospective, and observational study based on the medical records of patients from 0 to 18 years old seen at the emergency unit during the years of 2016-2019, who had a diagnosis potentially related to anaphylaxis according to ICD-10. All medical records were individually reviewed for the presence of compatible signs and symptoms that identified "possible" cases of anaphylaxis. Cases were considered probable anaphylaxis when medical history was compatible and indicative of anaphylaxis in the opinion of at least 2 allergists.

Results

The incidence of anaphylaxis was 0.013%. Among the 56 patients identified (mean age 4.2 years), food was the most predominant suspected factor (53%), followed by unknown factors (32%), and drugs (12.5%). All patients presented with cutaneous symptoms, 74% with respiratory, and 53% with gastrointestinal. Allergic disease as a comorbidity was found in 39% of the children and 11% had a history of previous anaphylaxis. There were neither cases of syncope or shock, nor deaths. Intramuscular (IM) adrenaline was prescribed in 37.5% of cases.

Conclusions

The incidence of anaphylaxis was low when compared to the worldwide incidence. The severity of most cases was mild, cutaneous symptoms were predominant, and food was the suspected trigger most frequently associated with reactions.

Epicutaneous allergen immunotherapy induces a profound and selective modulation in skin dendritic cell subsets

BACKGROUND

Epicutaneous immunotherapy (EPIT) protocols have recently been developed to restore tolerance in patients with food allergy (FA). The mechanisms by which EPIT protocols promote desensitization rely on a profound immune deviation of pathogenic T and B cell responses.

OBJECTIVE

To date, little is known about the contribution of skin dendritic cells (skDCs) to T cell remodeling and EPIT efficacy.

METHODS

We capitalized on a preclinical model of food allergy to ovalbumin (OVA) to characterize the phenotype and functions of OVA⁺ skDCs throughout the course of EPIT.

RESULTS

Our results showed that both Langerhans cells (LCs) and dermal conventional cDC1 and cDC2 subsets retained their ability to capture OVA in the skin and to migrate toward the skin-draining lymph nodes during EPIT. However, their activation/maturation status was significantly impaired, as evidenced by the gradual and selective reduction of CD86, CD40, and OVA protein expression in respective subsets. Phenotypic changes during EPIT were also characterized by a progressive diversification of single cell gene signatures within each DC subset. Interestingly, we observed that OVA⁺ LCs progressively lost their capacity to prime CD4⁺ T_EFF, but gained T_REG stimulatory properties. In contrast, cDC1 were inefficient in priming CD4⁺ T_EFF or in reactivating T_MEMin vitro, while cDC2 retained moderate stimulatory properties, and progressively biased type-2 immunity toward type-1 and type-17 responses.

CONCLUSIONS

Our results therefore emphasize that the acquisition of distinct phenotypic and functional specializations by skDCs during EPIT is at the cornerstone of the desensitization process.

Allergen immunotherapy and/or biologicals for IgE-mediated food allergy: A systematic review and meta-analysis

Background

There is substantial interest in immunotherapy and biologicals in IgE‐mediated food allergy.

Methods

We searched six databases for randomized controlled trials about immunotherapy alone or with biologicals (to April 2021) or biological monotherapy (to September 2021) in food allergy confirmed by oral food challenge. We pooled the data using random‐effects meta‐analysis.

Results

We included 36 trials about immunotherapy with 2126 mainly child participants. Oral immunotherapy increased tolerance whilst on therapy for peanut (RR 9.9, 95% CI 4.5.–21.4, high certainty); cow's milk (RR 5.7, 1.9–16.7, moderate certainty) and hen's egg allergy (RR 8.9, 4.4–18, moderate certainty). The number needed to treat to increase tolerance to a single dose of 300 mg or 1000 mg peanut protein was 2.

Oral immunotherapy did not increase adverse reactions (RR 1.1, 1.0–1.2, low certainty) or severe reactions in peanut allergy (RR 1,6, 0.7–3.5, low certainty), but may increase (mild) adverse reactions in cow's milk (RR 3.9, 2.1–7.5, low certainty) and hen's egg allergy (RR 7.0, 2.4–19.8, moderate certainty). Epicutaneous immunotherapy increased tolerance whilst on therapy for peanut (RR 2.6, 1.8–3.8, moderate certainty). Results were unclear for other allergies and administration routes.

There were too few trials of biologicals alone (3) or with immunotherapy (1) to draw conclusions.

Conclusions

Oral immunotherapy improves tolerance whilst on therapy and is probably safe in peanut, cow's milk and hen's egg allergy. More research is needed about quality of life, cost and biologicals.

Anaphylaxis knowledge gaps and future research priorities: A consensus report

BACKGROUND

Despite a better understanding of the epidemiology, pathogenesis, and management of patients with anaphylaxis, there remain knowledge gaps. Enumerating and prioritizing these gaps would allow limited scientific resources to be directed more effectively.

OBJECTIVE

We sought to systematically describe and appraise anaphylaxis knowledge gaps and future research priorities based on their potential impact and feasibility.

METHODS

We convened a 25-member multidisciplinary panel of anaphylaxis experts. Panelists formulated knowledge gaps/research priority statements in an anonymous electronic survey. Four anaphylaxis themed writing groups were formed to refine statements: (1) Population Science, (2) Basic and Translational Sciences, (3) Emergency Department Care/Acute Management, and (4) Long-Term Management Strategies and Prevention. Revised statements were incorporated into an anonymous electronic survey, and panelists were asked to rate the impact and feasibility of addressing statements on a continuous 0 to 100 scale.

RESULTS

The panel generated 98 statements across the 4 anaphylaxis themes: Population Science (29), Basic and Translational Sciences (27), Emergency Department Care/Acute Management (24), and Long-Term Management Strategies and Prevention (18). Median scores for impact and feasibility ranged from 50.0 to 95.0 and from 40.0 to 90.0, respectively. Key statements based on median rating for impact/feasibility included the need to refine anaphylaxis diagnostic criteria, identify reliable diagnostic, predictive, and prognostic anaphylaxis bioassays, develop clinical prediction models to standardize postanaphylaxis observation periods and hospitalization criteria, and determine immunotherapy best practices.

CONCLUSIONS

We identified and systematically appraised anaphylaxis knowledge gaps and future research priorities. This study reinforces the need to harmonize scientific pursuits to optimize the outcomes of patients with and at risk of anaphylaxis.

Maillard Reaction Induced Changes in Allergenicity of Food

Food allergy is increasing in prevalence, posing aheavier social and financial burden. At present, there is still no widely accepted treatment for it. Methods to reduce or eliminate the allergenicity of trigger foods are urgently needed. Technological processing contributes to producing some hypoallergenic foods. Among the processing methods, the Maillard reaction (MR) is popular because neither special chemical materials nor sophisticated equipment is needed. MR may affect the allergenicity of proteins by disrupting the conformational epitope, disclosing the hidden epitope, masking the linear epitope, and/or forming a new epitope. Changes in the allergenicity of foods after processing are affected by various factors, such as the characteristics of the allergen, the processing parameters, and the processing matrix, and they are therefore variable and difficult to predict. This paper reviews the effects of MR on the allergenicity of each allergen group from common allergenic foods.

Fatal Food Anaphylaxis: Distinguishing Fact From Fiction

Although there is a general perception that the prevalence of food allergy is increasing, data supporting this are limited. Food is the least common cause of fatal anaphylaxis, and fortunately, it is a very rare event; however, it is also unpredictable. There is widespread consensus that severe reactions cannot be predicted in a clinically meaningful way. Certain food triggers are more frequently associated with fatal anaphylaxis than others. In observational studies, peanut and tree nuts account for at least 30% to 50% of fatalities, with seafood and cow's milk also associated with fatal reactions. Fatal food-induced anaphylaxis is most likely to occur during adolescence and young adulthood, although the reasons for this are unclear. International guidelines agree that intramuscular (IM) epinephrine is the treatment of choice for managing food-triggered anaphylaxis and has a good safety profile when given by the IM route. However, fatalities still occur despite the timely administration of epinephrine. Food-allergic individuals must navigate a world that requires daily vigilance for allergens and preparedness for allergic reactions. Although the actual risk of fatal reactions is minimal, it is not zero, and severe reactions are unpredictable. Clinicians need to help patients better understand the very low but real risk of fatal reaction and enable them to lead as normal a life as possible through appropriate education, safety netting, and risk reduction.

Prognosis of food-induced anaphylaxis in children: A single-center real-life study

Background: Food allergies are known to resolve over time, but there is little information on the natural history of food-induced anaphylaxis (FIA). Objective: This study aimed to evaluate the natural history of FIA in children and determine the factors that affect prognosis. Methods: Children with FIA who were followed up for at least 3 years, between 2010 and 2020, were included. Patients' families were contacted by telephone to question their child's tolerance status and invite them for reevaluation if uncertain. The patients were grouped as tolerant or persistent according to parent reports or reevaluation results. Logistic regression analysis was performed to determine the factors that affected persistence. Results: The study included 185 patients (62.2% boys) with 243 anaphylactic reactions to various foods. Fifty-eight patients (31%) gained tolerance within a 3-year follow-up period. Tolerance rates were higher in patients with FIA to milk (40%) and egg (43.9%) compared with to tree nuts (18.8%), legumes (5.6%), and/or seafood (11.1%) (p < 0.001). In a multivariate analysis, risk factors for persistent FIA were multiple food anaphylaxis (odds ratio [OR] 3.755 [95% confidence interval {CI}, 1.134-12.431]; p = 0.030), total IgE > 100 kU/L (OR 5.786 [95% CI, 2.065-16.207]; p = 0.001), and skin-prick test wheal size > 10 mm (OR 4.569 [95% CI, 1.395-14.964]; p = 0 .012) at presentation. Conclusion: Approximately a third of the patients with FIA developed tolerance within 3 years. Clinicians should remember that children with food allergies, even anaphylaxis, may develop tolerance over time. Regular follow up and reevaluation of tolerance status are necessary to avoid unnecessary elimination.

Oral Immunotherapy in Food Allergy: A Critical Pediatric Perspective

There is evidence that in children with persistent IgE-mediated food allergy (FA) to cow's milk, hen's egg, and peanut, oral allergen-specific immunotherapy (OIT) may increase the reaction threshold to the culprit food allergen(s). OIT may protect patients from the occurrence of severe reactions in case of accidental ingestion of the culprit food during treatment. Notwithstanding, many gaps are still unsolved, including safety issues, identification of predictive biomarkers, and post-desensitization efficacy. In this perspective, the use of omalizumab (Anti-IgE monoclonal antibody) has been proposed as an adjunctive treatment to OIT in order to reduce the risk of allergic reactions related to OIT. This review aims to summarize the current evidence and unmet needs on OIT in children with FA to enhance the development of longitudinal, prospective, and well-designed studies able to fill the current gaps soon.