NUT Co Reactivity - ACquiring Knowledge for Elimination Recommendations (NUT CRACKER) study

Validation of the NUT CRACKER Diagnostic Algorithm and Prediction for Cashew and Pistachio Co-Allergy

BACKGROUND

Because of the high cross-sensitization among tree nuts, the NUT CRACKER (Nut Co-reactivity-Acquiring Knowledge for Elimination Recommendations) study proposed a diagnostic algorithm to minimize the number of required oral food challenges (OFCs).

OBJECTIVE

To validate the algorithm for cashew and pistachio allergy and determine markers for allergic severity.

METHODS

Patients (n = 125) with a median age of 7.8 (interquartile range, 5.9-11.2) years with suspected tree nut allergy were evaluated prospectively with decision tree points on the basis of skin prick test (SPT), basophil activation test (BAT), and knowledge of the coincidence of allergies. Validation of allergic status was determined by OFC. Markers of clinical severity were evaluated using the combined original and prospective cohort (n = 187) in relationship to SPT, BAT, and Ana o 3-sIgE.

RESULTS

Reactivity to cashew in SPT, BAT, and Ana o 3-sIgE and the incidence of abdominal pain on challenge were significantly higher in dual-allergic cashew/pistachio patients (n = 82) versus single cashew allergic patients (n = 18) (P = .001). All 3 diagnostic tests showed significant inverse correlation with log10 reaction doses for positive cashew OFC. The algorithm reduced overall the total number of OFCs by 72.0%, with a positive predictive value and negative predictive value of 93.0% and 99.0%, respectively. Cashew false-positives were observed primarily in hazelnut-allergic patients (P = .026). In this population, Ana o 3-specific IgE could diagnose cashew allergy with a sensitivity of more than 90% and a specificity of more than 95%.

CONCLUSIONS

The NUT CRACKER diagnostic algorithm was validated and reduced the number of diagnostic OFCs required. Markers for severity phenotypes may guide oral immunotherapy protocols, improving the risk/benefit ratio for patients.

Basophil activation test in the food allergy clinic: its current use and future applications

INTRODUCTION

The basophil activation test (BAT) has shown evidence of high sensitivity and high specificity to support the diagnosis of IgE-mediated allergy. It is a functional test that uses live cells analyzed by flow cytometry and thus needs to be performed within 24h of blood collection. BAT has shown to be reproducible and reliable when tested in a clinical diagnostic laboratory with standardized protocols and flow cytometry settings.

AREAS COVERED

In this review, we summarize the evidence to support clinical use of BAT and the next steps required for clinical implementation for an improve clinical care for patients with suspected IgE-mediated food allergy.

EXPERT OPINION

BAT has recently been included in Clinical Guidelines of Food Allergy Diagnosis and its implementation in clinical practice depends largely on availability. Proposed clinical applications of the BAT include: distinction between food allergy and asymptomatic IgE sensitization; determination of food allergic status to peanut, tree nuts and seeds in polysensitized children; evaluation of tolerance to baked egg and baked milk in egg and milk allergic children; identification of patients at high-risk of severe allergic reactions; monitoring for spontaneous resolution of food allergy; confirmation of eligibility for specific treatments of food allergy; prediction and monitoring of response to immunomodulatory treatments.

Prevalence of tree nut allergy in Europe: A systematic review and meta-analysis

In 2014, the European Academy of Allergy and Clinical Immunology (EAACI) published the first systematic review that summarized the prevalence of food allergy (FA) and food sensitization in Europe for studies published 2000-2012. However, only summary estimates for tree nut allergy (TNA) were feasible in that work. In the current update of that systematic review, we summarized the prevalence of tree nut allergy/sensitization to individual tree nuts. Six databases were searched for relevant papers published 2012-2021 and 17 eligible studies were added to the 15 studies already identified between 2000 and 2012, giving a total of 32 studies. Of the investigated tree nuts, meta-analysis was possible for hazelnut, walnut, almond, and in few cases, for cashew, and Brazil nut. The lifetime self-reported prevalence was 0.8% (95% CI 0.5-1.1) for hazelnut and 0.4% (0.2-0.9) for walnut. The point self-reported prevalence was 4.0% (2.9-5.2) for hazelnut, 3.4% (2.0-4.9) for Brazil nut, 2.0% (1.1-2.9) for almond, and 1.8% (1.1-2.5) for walnut. Point prevalence of food challenge-confirmed TNA was 0.04% (0.0-0.1) for hazelnut and 0.02% (0.01-0.1) for walnut. Due to paucity of data, we could not identify any meaningful and consistent differences across age groups and European regions.

Eosinophil-Associated Gastrointestinal Manifestations During OIT

Gastrointestinal adverse events are common during oral immunotherapy (OIT) for food allergy and range from immediate IgE-mediated reactions to non-anaphylactic clinical presentations. This review aims to summarize recent findings on non-anaphylactic eosinophil-associated gastrointestinal adverse events during OIT. Two clinical presentations of non-anaphylactic eosinophil-associated gastrointestinal adverse events during OIT are identified, each with a different paradigm for treatment, and distinguished by their time of onset. In the first clinical entity, characterized by its onset early in the course of treatment, patients present with abdominal pain, nausea, and/or vomiting. The symptoms become evident typically within weeks to months of starting OIT. These symptoms, however, are not temporally related to the time of dose administration, as in the case of immediate IgE-mediated anaphylactic reactions. While esophageal biopsies, when performed, can demonstrate eosinophilic esophagitis (EoE), baseline esophageal eosinophilia has also been observed in food allergic patients prior to OIT. A potential non-invasive biomarker, the peripheral absolute eosinophil count (AEC), often rises during these reactions and subsides after dose reduction and subsequent resolution of symptoms. OIT can usually then be resumed, albeit at a slower pace, without a recurrence of symptoms. Risk factors for development of symptoms early during OIT include a high starting dose and a baseline AEC of greater than 600. The second, and much less frequently encountered, non-anaphylactic gastrointestinal adverse event related to OIT, presents months to years after initiating OIT. In this latter group, patients present with the classical clinical symptoms and endoscopic findings of EoE. In contrast to the acute onset group, peripheral eosinophilia is usually not observed in these cases. This OIT-associated EoE has shown good response to standard EoE treatment approaches of proton pump inhibitors or swallowed steroids. Most patients with eosinophil-associated adverse reactions are able to continue OIT and remain desensitized. Treatment approaches depend on the specific subtype of these reactions and relate to the stages of OIT treatment.

An update on recent developments and highlights in food allergy

While both the incidence and general awareness of food allergies is increasing, the variety and clinical availability of therapeutics remain limited. Therefore, investigations into the potential factors contributing to the development of food allergy (FA) and the mechanisms of natural tolerance or induced desensitization are required. In addition, a detailed understanding of the pathophysiology of food allergies is needed to generate compelling, enduring, and safe treatment options. New findings regarding the contribution of barrier function, the effect of emollient interventions, mechanisms of allergen recognition, and the contributions of specific immune cell subsets through rodent models and human clinical studies provide novel insights. With the first approved treatment for peanut allergy, the clinical management of FA is evolving toward less intensive, alternative approaches involving fixed doses, lower maintenance dose targets, coadministration of biologicals, adjuvants, and tolerance-inducing formulations. The ultimate goal is to improve immunotherapy and develop precision-based medicine via risk phenotyping allowing optimal treatment for each food-allergic patient.

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.

Safety of Multifood Oral Immunotherapy in Children Aged 1 to 18 Years at an Academic Pediatric Clinic

BACKGROUND

Oral immunotherapy (OIT) aims to increase the reaction threshold to a food allergen and decrease the risk of a potentially life-threatening allergic reaction in the event of an accidental ingestion. Whereas single-food OIT is the most extensively studied, data on multifood OIT are limited.

OBJECTIVE

Our study aimed to examine the safety and feasibility of single-food and multifood immunotherapy in a large cohort in an outpatient pediatric allergy clinic setting.

METHODS

A retrospective review of patients enrolled in single-food and multifood OIT between September 1, 2019, and September 30, 2020, and data collection of those patients until November 19, 2021, were performed.

RESULTS

There were 151 patients who underwent either an initial dose escalation (IDE) or a standard oral food challenge. Seventy-eight patients were receiving single-food OIT with 67.9% reaching maintenance. Fifty patients were undergoing multifood OIT with 86% reaching maintenance to at least 1 OIT food and 68% reaching maintenance for all their foods. Of the 229 IDEs, there were low frequencies of failed IDEs (10.9%), epinephrine administration (8.7%), emergency department referrals (0.4%), and hospital admission (0.4%). Cashew accounted for one-third of failed IDEs. Epinephrine administration during home dosing occurred in 8.6% of patients. Eleven patients discontinued OIT owing to symptoms during up-dosing. No patients discontinued once reaching maintenance.

CONCLUSIONS

Desensitization to 1 food or multiple foods simultaneously through OIT appears to be safe and feasible using the OIT protocol that has been established. The most common adverse reaction causing discontinuation of OIT was gastrointestinal symptoms.

Impact of Presumed Tree Nut and Peanut Allergy on Quality of Life at Different Ages

Tree nut and/or peanut allergy impairs patients' quality of life, but data on the impact of age and the type of nut or peanut on the quality of life are lacking. To evaluate the impact at different ages, age-appropriate survey questionnaires accompanied by FAQLQ and FAIM were distributed to patients with suspected tree nut and/or peanut allergy who presented at the allergy departments of three hospitals in Athens. Out of 200 questionnaires distributed, 106 met the inclusion criteria (46 children, 26 teenagers, 34 adults). The median score of each age group for FAQLQ was 4.6 (3.3-5.1), 4.7 (3.9-5.5), and 3.9 (3.2-5.1) and for FAIM was 3.7 (3.0-4.0), 3.4 (2.8-4.0), and 3.2 (2.7-4.1), respectively. FAQLQ and FAIM scores were correlated with the reported probability of using the rescue anaphylaxis set upon reaction (15.4%, p = 0.04 and 17.8%, p = 0.02, respectively) and pistachio allergy (FAQLQ: 4.8 vs. 4.0, p = 0.04; FAIM: 3.5 vs. 3.2, p = 0.03). Patients with additional food allergies reported worse FAQLQ scores (4.6 vs. 3.8, p = 0.05). Worse FAIM scores were associated with younger age (-18.2%, p = 0.01) and the number of life-threatening allergic reactions (25.3%, p < 0.001). The overall impact of tree nut and/or peanut allergy on patients' quality of life is moderate but differs with age, the type of nut, the use of adrenaline, and the number of previous reactions. The aspects of life affected and contributed factors also vary across age groups.

Natural History of Hazelnut Allergy and Current Approach to Its Diagnosis and Treatment

Hazelnut allergy is the most prevalent type of nut allergy in Europe, with symptoms that can range from mild, such as hives and itching, to severe, such as anaphylaxis, particularly in patients who are sensitized to highly stable allergens, such as storage proteins. Compared to other types of food allergies, allergies to tree nuts, including hazelnuts, tend to persist throughout life. Although symptoms can appear in early childhood, they often continue into adulthood, with a minority of cases improving during adolescence. Currently, there is no curative treatment available for hazelnut allergy, and patients must adhere to a restrictive diet and carry autoinjective epinephrine. However, oral allergen immunotherapy (AIT) is a promising treatment option. Patients can be categorized based on their risk for severe reactions using various clinical, in vivo, and in vitro tests, including component-resolved diagnosis and oral food challenge. This review aims to provide an overview of the current knowledge of the natural history of hazelnut allergy and new approaches for its diagnosis and management.

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.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Characteristics of patients diagnosed as non-allergic following food allergy oral immunotherapy referral

BACKGROUND

Ascribing food allergy diagnosis to patients who are not allergic is well described, but its implications on oral immunotherapy (OIT) have not been studied. The aim was to study non-allergic patients referred for OIT.

METHODS

All patients who began OIT at Shamir Medical Center between November 2015 and August 2020 were included. Medical records were reviewed, and skin prick tests (SPT) and/or specific IgE were measured. Patients were challenged to the index food. Allergic and non-allergic patients were compared.

RESULTS

A total of 1073 patients were studied (milk, n = 327; egg, n = 41; peanut, n = 272; sesame, n = 130; and tree nuts, n = 303) and 87 (8.1%) were found non-allergic (milk, n = 21; egg, n = 6; sesame, n = 5; peanut, n = 29; tree nuts, n = 26). Predictors of being not allergic were no previous reaction to the index food (OR = 3.3, p = 0.001), not having asthma (OR = 2.4, p = 0.001), or HDM sensitization (OR = 2.0, p = 0.007), male sex (OR = 2.3, p = 0.004), and a smaller SPT wheal size (OR = 1.5, p < 0.001).

CONCLUSIONS

A substantial number of patients referred for OIT are mislabeled with food allergy, suffer from unjustly food limitations and impairments in quality of life, and "take up" OIT places of true allergic patients. Awareness of OIT centers to this phenomenon is important.

IMPACT

A significant number (8.1%) of patients referred for OIT are found not allergic to the food they intended to treat. This study characterizes non-allergic patients referred for OIT (a lack of previous reaction to the index food, a smaller or negative SPT wheal size, and less atopic co-morbidities) and discusses the implications of such referrals. Increased awareness by OIT centers to potential non-allergic patients referred for OIT is required, including screening of patients before treatment initiation, to minimize unnecessary treatments of non-allergic patients.

Feasibility of the ALEX multiplex platform in the diagnosis of nut allergy from a Mediterranean population

BACKGROUND

ALEX multiplex platform has been recently commercialized but its clinical utility as quantitative technique respect to ImmunoCAP-singleplex as the reference method has not yet been confirmed on patients suffering from nut allergy and co-sensitization to different nuts.

METHODS

58 serum samples from patients with nut allergy from a Mediterranean population were assayed in parallel by ALEX-multiplex and ImmunoCAP-singleplex techniques. Patients were diagnosed based on clinical symptoms and positive skin prick tests (SPTs). The following whole extracts were compared between both techniques: walnut, hazelnut, peanut, almond, pistachio and sunflower seed; besides the recombinant Pru p 3. A qualitative and quantitative study was carried out.

RESULTS

Both techniques had similar sensitivities respect to whole extracts from walnut, hazelnut and peanut as well as to Pru p 3 (p > 0.05). However for whole extracts from almond, pistachio and sunflower seed the sensitivity obtained by ALEX was much lower than ImmunoCAP (9.09 % vs 88.63 %; 14.81 vs 70.37 %; and 8.51 % vs 88.88 %; respectively). The concordance between both techniques showed only a substantial agreement for Pru p 3 (k = 0.791); moderate agreement for hazelnut and peanut (k = 0.550 and k = 0.544, respectively); fair agreement for walnut (k = 0.386) and poor agreement for almond, pistachio and sunflower seed (k < 0.2). Quantitative analysis showed that ImmunoCAP for walnut, peanut and sunflower seed had higher mean values than ALEX. Relationships were significant for all specific IgE levels except to for almond, pistachio and sunflower seed.

CONCLUSIONS

ALEX platform is a suitable technique to patients with nut allergy from the Mediterranean area except to for those suffering from allergy to almond, pistachio and sunflower seed.

Pathogenesis, diagnosis, dietary management, and prevention of gastrointestinal disorders in the paediatric population

Nutrition has a central role in child growth with long-term effects, and nutrition management in gastrointestinal disorders has great importance for child health and disease outcomes. Breast milk is the first choice for infant nutrition. When it is not available, special milk formulas are adopted in specific conditions, as a medical treatment. Moving from the strong guidelines, recommendations and the new possibilities of special diet treatment, this review will analyse the current diet treatment in different gastrointestinal disorders, including food allergy, cystic fibrosis, inflammatory bowel diseases, short-bowel syndrome, gastroesophageal reflux, and eosinophilic esophagitis. The review also aimed at understanding the role of diet and its effects on these diseases. The growth monitoring can prevent malnutrition and improve disease outcomes, particularly in children, and an appropriate dietary management targeted to specific disorders is the best therapeutic choice alone or in combination with pharmacological therapy.

Ana o 3 sIgE and diagnostic algorithms reduce cost of cashew allergy diagnosis in children compared with skin prick test: A cost comparison analysis

BACKGROUND

In the absence of a clear clinical history of reaction, diagnosis of cashew allergy using skin prick tests (SPT) or cashew-specific IgE requires a high number of oral food challenges (OFC). By using Ana o 3 sIgE alone, or a two-step diagnostic algorithm using cashew sIgE followed by Ana o 3 sIgE, there is a reduced need for OFC. We aimed to perform a cost comparison for both of these approaches compared with cashew SPT alone.

METHODS

Pooled individual-level data from 6 studies were used to determine diagnostic accuracy and OFC rate. Two studies used cashew SPT (n = 567, 198 allergic), with 95% positive and negative predictive values of ≥12 mm and <3 mm. Four studies were included in the pathways for Ana o 3 sIgE alone or a 2-step algorithm incorporating cashew and Ana o 3 sIgE (n = 271, 156 allergic). Cut-offs used were ≥8.5kUA/L and ≤0.1kUA/L for cashew sIgE and ≥0.35kUA/L and ≤0.1kUA/L for Ana o 3 sIgE. Costs were constructed based on unit prices from hospital inpatient admissions, expenses incurred by families, individual patient data on allergic reaction types and rates, and adrenaline autoinjector carriage, applying a health system perspective.

RESULTS

Modeled data through the Ana o 3 pathway resulted in a 46.43% cost reduction (€307,406/1000 patients) compared with using cashew SPT alone (€573,854/1000 patients). The 2-step algorithm resulted in a 44.94% cost reduction compared with SPT alone (€315,952.82/1000 patients). Both the Ana o 3 pathway and 2-step algorithm resulted in a 79%-80% reduction in OFCs compared with SPT.

CONCLUSIONS

Using Ana o 3 as a standalone test for cashew allergy diagnosis or a 2-step algorithm incorporating cashew sIgE and Ana o 3 sIgE is accurate and results in a large reduction in both OFCs and health system costs compared with cashew SPT alone.

A practical focus on multi-food oral immunotherapy

Approximately one-third of patients who present for oral immunotherapy (OIT) will be allergic to more than one food. Those patients with more than one food allergy have the option of sequential courses of single-food OIT or, in the right situation, combining several foods as part of multifood OIT. The time and cost savings can be substantial. Treatment protocols used with multiple foods are basically the same as with single-food courses, so clinics proficient with single-food OIT can easily transition to multifood OIT. Outcomes have been shown to be similar between the two approaches, so patients should be offered the opportunity to address their food allergies in one, more convenient OIT course.

Cashew oral immunotherapy for desensitizing cashew-pistachio allergy (NUT CRACKER study)

BACKGROUND

Oral immunotherapy (OIT) is a treatment option for patients with milk, egg, and peanut allergy, but data on the efficacy and safety of cashew OIT are limited.

METHODS

A cohort of 50 cashew-allergic patients aged ≥4 years, who were consecutively enrolled into cashew OIT (target dose 4000 mg protein) between 4/2016 and 12/2019. Fifteen cashew-allergic patients who continued cashew elimination served as observational controls. Co-allergy to pistachio and walnut was determined. Full desensitization rate and associated immunological changes in both groups were compared. Patients fully desensitized to cashew were instructed to consume a dose of 1200 mg cashew protein for 6 months and were then challenged to a full dose. Patients with co-allergy to pistachio or walnut were challenged to the respective nut.

RESULTS

Forty-four of 50 OIT-treated patients (88%) compared to 0% in controls tolerated a dose of 4000 mg cashew protein at the end of the study (odds ratio 8.3, 95% CI 3.9-17.7, p < 0.001). An additional three patients were desensitized to 1200 mg cashew protein, and three patients stopped treatment. Three patients (6%) were treated with injectable epinephrine for home reactions. Desensitized patients had decreased SPT, sIgE, basophil reactivity, and increased sIgG4, following treatment. Following cashew desensitization, all pistachio (n = 35) and four of eight walnut co-allergic patients were cross-desensitized to the respective nut. All (n = 44) patients consuming a low cashew dose for ≥6 months following desensitization passed a full-dose cashew OFC.

CONCLUSIONS

Cashew OIT desensitizes most cashew-allergic patients and cross-desensitizes to pistachio. Safety is similar to OIT for other foods.

Organ-specific symptom patterns during oral food challenge in children with peanut and tree nut allergy

BACKGROUND

Peanut and tree nut allergies are common in childhood and often severe in nature. The clinical picture shows a wide variety of symptoms.

OBJECTIVE

To analyze the distribution of clinical symptoms and severity during oral food challenges (OFC) in children.

METHODS

Analysis of 1.013 prospectively recorded, positive OFCs with peanut (n = 607), hazelnut (n = 266), walnut (n = 97), and cashew (n = 43). Symptoms were categorized as immediate-type skin, gastrointestinal, upper and lower respiratory, cardiovascular symptoms, and eczema exacerbation. Symptom severity and treatment were recorded.

RESULTS

Skin symptoms presented in 78%, followed by gastrointestinal (47%), upper (42%), and lower respiratory symptoms (32%). Cardiovascular symptoms presented in 6%. In three-quarter of the reactions, more than one organ was involved. Importantly, severe reactions occurred at every dose level. Peanut- and cashew-allergic patients had a higher relative risk of gastrointestinal symptoms compared with hazelnut- and walnut-allergic patients. Patients without vomiting had a 1.7 times higher risk developing immediate-type skin and/or lower respiratory symptoms. Three-quarter of the patients ever had eczema but worsening presented in only 10.5% of the OFCs. In patients with multiple food allergies, organs involved, eliciting dose and severity differed between allergens.

CONCLUSION

Although comparisons between allergen groups with different clinical history, severity, comorbidities and laboratory data are difficult and might contain bias, our data confirm the high allergenic potential of peanut and tree nuts. The rare occurrence of eczema worsening emphasizes that avoidance diets of peanuts and tree nuts to cure eczema seem to be unnecessary and may hamper tolerance maintenance.

Patterns of Clinical Reactivity in a Danish Cohort of Tree Nut Allergic Children, Adolescents, and Young Adults

Background

Tree nut allergy is associated with severe reactions and poly-sensitization to other nuts and peanuts often occurs. There are regional differences in sensitization profiles that result in differences in clinical presentation. Denmark is located in a birch pollen endemic area, which could influence the allergy patterns due to pollen cross-sensitization.

Objective

This study aimed to investigate patterns of sensitization and clinical reactivity to tree nuts and peanuts and threshold levels for oral food challenges (OFCs) in a Danish cohort of tree nut allergic children, adolescents, and young adults.

Methods

Forty tree nut allergic subjects were assessed for clinical reactivity to six nuts, i.e., hazelnut, walnut, pistachio, cashew, almond, and peanut, by OFCs or convincing medical history of an immediate allergic reaction or tolerance. Clinical presentation and allergen-specific immunoglobulin E (sIgE) levels together with eliciting dose and rescue medication in OFCs were furthermore assessed.

Results

Allergy to two or more tree nuts was observed in most cases. Hazelnut-walnut dual allergy was common but not exclusively observed as concomitant allergies. Allergy to cashew was coincided in all but one of the assessed subjects with pistachio allergy. Half of all assessed subjects were allergic to peanuts. Oral symptoms followed by a skin reaction were the most common symptomatology that lead to OFC cessation and subjects often presented with symptoms from two or more organ systems. OFC threshold levels were within the same range, but cashew was distinguished from other nuts by causing allergic symptoms at the lowest dose. Clinical reactivity and the allergy patterns were to some extent reflected by sIgE levels and by correlations in sIgE between the nuts.

Conclusions

In this Northern European cohort, subjects with clinically relevant tree nut allergy were generally allergic to two or more tree nuts and close to half of them also to peanuts. There were two distinct and independent allergic phenotypes; the majority of hazelnut allergic subjects were also allergic to walnut, and all but one subject with cashew allergy were dual allergic to pistachio. These findings are consistent with a strong sIgE correlation between hazelnut and walnut and a close to total sIgE correlation between cashew and pistachio.

Tree Nuts and Peanuts as a Source of Beneficial Compounds and a Threat for Allergic Consumers: Overview on Methods for Their Detection in Complex Food Products

Consumption of tree nuts and peanuts has considerably increased over the last decades due to their nutritional composition and the content of beneficial compounds. On the other hand, such widespread consumption worldwide has also generated a growing incidence of allergy in the sensitive population. Allergy to nuts and peanuts represents a global relevant problem, especially due to the risk of the ingestion of hidden allergens as a result of cross-contamination between production lines at industrial level occurring during food manufacturing. The present review provides insights on peanuts, almonds, and four nut allergens—namely hazelnuts, walnuts, cashew, and pistachios—that are likely to cross-contaminate different food commodities. The paper aims at covering both the biochemical aspect linked to the identified allergenic proteins for each allergen category and the different methodological approaches developed for allergens detection and identification. Attention has been also paid to mass spectrometry methods and to current efforts of the scientific community to identify a harmonized approach for allergens quantification through the detection of allergen markers.

Molecularly imprinted polymer as a synthetic antibody for the biorecognition of hazelnut Cor a 14-allergen

Artificial receptors that mimic their natural biological counterparts have several advantages, such as lower production costs and increased shelf-life stability/versatility, while overcoming the ethical issues related to raising antibodies in animals. In this work, the proposed tailor-made molecularly imprinted polymer (MIP)-allergen receptors aimed at substituting or even transcending the performance of biological antibodies. For this purpose, a MIP was proposed as an artificial antibody for the recognition of hazelnut Cor a 14-allergen. The target protein was grafted onto the conducting polypyrrole receptor film using gold screen-printed electrodes (Au-SPE). The electrochemical assessment presented a linear response for the dynamic range of 100 fg mL^-1-1 μg mL^-1 and a LOD of 24.5 fg mL^-1, as determined by square wave voltammetry from the calibration curves prepared with standards diluted in phosphate buffer. Surface plasmon resonance (SPR) was used as a secondary transducer to evaluate the performance of the Cor a 14-MIP sensor, enabling a linear dynamic range of 100 fg mL^-1- 0.1 μg mL^-1 and a LOD of 18.1 fg mL^-1. The selectivity of the tailored-made Cor a 14-MIP was tested against potentially cross-reactive plant/animal species based on the rebinding affinity (Freundlich isotherm-K_F) of homologues/similar proteins, being further compared with custom-made polyclonal anti-Cor a 14 IgG immunosensor. Results evidenced that the MIP mimics the biorecognition of biological antibodies, presenting higher selectivity (only minor cross-reactivity towards walnut and Brazil nut 2S albumins) than the Cor a 14/anti-Cor a 14 IgG immunosensor. The application of electrochemical Cor a 14-MIP sensor to model mixtures of hazelnut in pasta enabled quantifying hazelnut down to 1 mg kg^-1 (corresponding to 0.16 mg kg^-1 of hazelnut protein in the matrix). To the best of our knowledge, Cor a 14-MIP is the first sensor based on an artificial/synthetic biorecognition platform for the specific detection of hazelnut allergens, while presenting high-performance parameters with demonstrated application in food safety management.

Protocol for a systematic review of the diagnostic test accuracy of tests for IgE-mediated food allergy

BACKGROUND

The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of updating the guidelines on the diagnosis and management of food allergy. The existing guidelines are based on a systematic review of the literature until 30 September 2012. Therefore, a new systematic review must be undertaken to inform the new guidelines. This systematic review aims to assess the accuracy of index tests to support the diagnosis of IgE-mediated food allergy.

METHODS

The databases Cochrane CENTRAL (Trials), MEDLINE (OVID) and Embase (OVID) will be searched for diagnostic test accuracy studies from 1 October 2012 to 30 June 2021. Inclusion and exclusion criteria will be used to select appropriate studies. Data from these studies will be extracted and tabulated, and then reviewed for risk of bias and applicability using the QUADAS-2 tool. All evaluations will be done in duplicate. Studies with a high risk of bias and low applicability will be excluded. Meta-analysis will be performed if there are three or more studies of the same index test and food.

RESULTS

A protocol for the systematic review and meta-analyses is presented and was registered using Prospero prior to commencing the literature search.

DISCUSSION

Oral food challenges are the reference standard for diagnosis but involve considerable risks and resources. This protocol for systematic review aims to assess the accuracy of various tests to diagnose food allergy, which can be useful in both clinical and research settings.

Advances, Practical Implementation, and Unmet Needs Regarding Oral Immunotherapy for Food Allergy

Treatment of food allergy is a rapidly changing landscape, with arguably, the most significant advancement in recent years, the transition of oral immunotherapy (OIT) to clinical practice. As an innovation, OIT is a phase of rapidly increasing demand, particularly for some allergens such as peanut, egg, and milk, which have substantial evidence of efficacy. However, significant questions remain about how to best treat multiple food allergies and less common food allergies and how to optimize long-term safety and efficacy. This review summarizes the currently available resources for integrating food allergy OIT into clinical practice and focuses on the multiple remaining unmet needs such as providing an approach for OIT to food allergens for which there is no or limited evidence; practical issues related to food allergy treatment particularly when it is not going well; long-term outcomes and follow-up after OIT; and strategies to help meet the impending increase in demand.

Optimizing tools for evaluating challenge outcomes in children with cashew nut allergy

BACKGROUND

The incidence of cashew nut anaphylaxis is increasing and there is a need for accurate diagnostic tests. Age-specific cutoffs in children are lacking. Changes in serum tryptase levels are not well documented in pediatric food allergy, except in anaphylaxis.

OBJECTIVE

To evaluate the ability of various tests to diagnose cashew nut allergy and to predict reaction severity. We also investigated changes in tryptase and their correlation to reaction severity.

METHODS

We performed an open cashew nut challenge on 106 children (aged 1-16 years), who were sensitized to cashew nut with either previous allergic reaction to cashew nut or no known exposure. We analyzed the accuracy of Ana o 3 immunoglobulin E (IgE), cashew nut IgE, skin prick test, basophil activation test (BAT), and combinations thereof to diagnose cashew nut allergy and to predict reaction severity. Tryptase level was measured at the baseline and during an allergic reaction.

RESULTS

A total of 72 children had positive challenge outcomes. Ana o 3 IgE seemed to be the best single test to diagnose cashew allergy, with a 0.97 kU/L cutoff exhibiting 94.1% specificity and 61.1% sensitivity. Though BAT values of at least 22.8% best predicted reaction severity, with 91.7% specificity and 60.7% sensitivity, the cutoffs were age-specific. Tryptase levels increased substantially 1 to 2 hours after the first allergic symptoms compared with baseline.

CONCLUSION

Ana o 3 IgE seems to be the best diagnostic test in pediatric cashew nut allergy, and test combinations do not seem to improve the diagnostics. Cutoffs are age-specific. BAT is promising in predicting reaction severity. Tryptase levels should be measured 1 to 2 hours after initiation of an allergic reaction.

Nut Allergy: Clinical and Allergological Features in Italian Children

BACKGROUND

Nut allergies are an increasingly frequent health issue in the pediatric population. Tree nuts (TN) and peanuts are the second cause of food anaphylaxis in Italy. Unfortunately, knowledge of the clinical characteristics of a TN allergy in Italian children is limited. Our study aimed to identify the clinical and allergological characteristics of Italian children with a nut allergy (TN and peanut).

METHODS

A retrospective observational analysis was performed on the clinical charts of children with a history of nut reaction referred to the allergy unit of the hospital from 2015 to 2019. The studied population was represented by children with a confirmed nut allergy based on positive prick by prick and/or serum-specific IgE to nut plus a positive nut oral food challenge. Demographic, clinical, and allergological features were studied and compared among different nuts.

RESULTS

In total, 318 clinical charts were reviewed. Nut allergy was confirmed in 113 patients. Most patients (85/113, 75%) had a familial history of allergy and/or a concomitant allergic disorder (77/113, 68%). Hazelnut and walnut were the more common culprit nuts observed in allergic children. Anaphylaxis was the first clinical manifestation of nut allergy in a high percentage of children (54/113, 48%). The mean age of the first nut reaction was statistically higher with pine nuts. Over 75% of children reported a single nut reaction. During the OFCs, the signs and symptoms involved mainly the gastrointestinal system (82/113, 73%) and resolved spontaneously in most cases. Severe reactions were not frequent (22/113, 19%).

CONCLUSION

To our knowledge, this is the first Italian study that provided a comprehensive characterization of children with a nut allergy. These results are important for clinicians treating children with a nut allergy.

The Basophil Activation Test for Clinical Management of Food Allergies: Recent Advances and Future Directions

The basophil activation test (BAT) is an ex vivo functional assay that measures by flow cytometry the degree of basophil degranulation after stimulation with an allergen. In recent years, there has been an increased interest in the diagnostic value of the BAT as it has the potential to mimic the clinical phenotype of sIgE sensitized patients, in contrast to allergen-specific IgE levels. This diagnostic potential would be of particular interest for food allergies present early in life such as peanut, cow’s milk and eggs, which require an expensive, time-consuming and patient unfriendly oral food challenge (OFC) for diagnosis. However, routine applications of the BAT for clinical use are not yet feasible due to the lack of standardized protocols and large clinical validation studies. This review will summarize the current data regarding the application of the BAT in food allergy (FA) for cow’s milk, egg and peanut, being the most common causes of FA in children. Additionally, it will discuss the hurdles for widespread clinical use of the BAT and possible future directions for this diagnostic procedure.

Use of multiple epinephrine doses in anaphylaxis: A systematic review and meta-analysis

BACKGROUND

Regulatory bodies recommend that all patients at risk of anaphylaxis be prescribed 2 epinephrine autoinjectors, which they should carry at all times. This is in contrast to some guidelines. The proportion of anaphylaxis reactions that are treated with multiple doses of epinephrine has not been systematically evaluated.

OBJECTIVE

Our aim was to undertake a systematic review and meta-analysis of published studies reporting epinephrine treatment for anaphylaxis in which data relating to the number of doses administered were available.

METHODS

We searched the Medline, Embase, and Cochrane databases for relevant studies reporting at least 10 anaphylaxis events (due to food or venom) from 1946 until January 2020. Data were extracted in duplicate for the meta-analysis, and the risk of bias was assessed. The study was registered under the PROSPERO identifier CRD42017069109.

RESULTS

A total of 86 studies (36,557 anaphylaxis events) met the inclusion criteria (20 of the studies [23%] were prospective studies; 64 [74%] reported reactions in the community, and 22 [26%] included food challenge data). Risk of bias was assessed as low in 50 studies. Overall, 7.7% of anaphylaxis events from any cause (95% CI = 6.4-9.1) were treated with multiple doses of epinephrine. When only epinephrine-treated reactions for which subsequent doses were administered by a health care professional were considered, 11.1% of food-induced reactions (95% CI = 9.4-13.2) and 17.1% of venom-induced reactions (95% CI = 11.3-25.0) were treated with more than 1 epinephrine dose. Heterogeneity was moderate to high in the meta-analyses, but at sensitivity analysis this estimate was not affected by study design or anaphylaxis definition.

CONCLUSION

Around 1 in 10 anaphylaxis reactions are treated with more than 1 dose of epinephrine.

Tree nut allergy

From a botanical point of view, a nut is a kind of dry, closed, unbroken, single-seeded fruit, which has a ligneous pericarp made up of several fruiting bodies surrounded by one free semen. The term “allergy to tree nuts” includes allergies to almonds, Brazil nuts, cashew nuts, hazelnuts, chestnuts, macadamia nuts, pecan nuts, pistachios and walnuts. All tree nuts belong to five orders of plants: Rosaceae, Fagales, Sapindales, Ericales and Proteales. Allergies to tree nuts usually start in childhood, but unlike other food allergies, they rarely fade away and generally persist throughout life. They are one of the main causes of serious allergic reactions ending in death in both children and adults. The epidemiology of allergy to nuts is variable and depends mainly on the geographical zone and eating habits. In northern Europe, hazelnut allergy is prevalent, whereas in the USA the most common is allergy to peanuts and, when taking tree nuts into consideration, to walnuts. The diagnosis of allergies to nuts is difficult and requires the use of the most modern research tools including molecular diagnostic techniques.

Combinatorial advantage of Ses i 1-specific IgE and basophil activation for diagnosis of sesame food allergy

BACKGROUND

The prevalence of sesame food allergy (SFA) is increasing worldwide with the potential of anaphylactic reactions upon exposure. Utility of specific component IgE testing as an alternative to the oral food challenge (OFC), the diagnostic standard, is being investigated.

METHODS

Patients (n = 42) with suspected SFA completed an open OFC to sesame. Diagnostic testing included serum levels of Ses i 1-specific IgE, skin prick test with high-protein extract, and basophil reactivity (% induced CD63 expression) for each patient. The diagnostic utility of these tests was evaluated at a 95% sensitivity, with the outcome measure being the number of OFCs required.

RESULTS

Twenty-seven patients (64%) were diagnosed with SFA. Ses i 1 IgE differed significantly between allergic and tolerant patients (p = .0001). ROC curve analysis for Ses i 1 IgE yielded an AUC of 0.88 ± 0.05. Levels of Ses i 1 IgE correlated to induced CD63+ expression on basophils (p = .0001). Ses i 1 IgE was not sufficiently robust as a single step for diagnosis. Used concurrently, BAT and Ses i 1 IgE yielded correct positive classifications for 25 of 27 sesame-allergic patients with two false positives (93% PPV). Both tests were negative in 5 non-allergic patients. Patients with divergent Ses i 1 IgE and BAT results required OFC (n = 10, 24% of patients). Alternatively, sequential use of BAT, ruling in SFA followed by Ses i 1 IgE diagnosing non-allergic patients, yielded a 89% PPV, with 19% requiring OFC.

CONCLUSION

Ses i 1 IgE and BAT used together can decrease the need for OFC in most SFA patients. A prospective cohort trial is necessary to validate these results.

Bringing the Next Generation of Food Allergy Diagnostics into the Clinic

Food allergy diagnosis has a massive impact on the lives of patients and their families. Despite recent developments with specific IgE to component allergens, a significant proportion of patients assessed for possible food allergy require oral food challenge to ensure an accurate diagnosis. More precise diagnostic methods are required to reduce the need for oral food challenges. Bead-based epitope assays and cellular tests, such as basophil activation and mast cell tests are the most novel and promising tests on the horizon. There is a pathway to pursue to enable their incorporation in clinical practice, including standardization, technical validation, clinical validation, external validation, overcoming practical and logistical issues, and regulatory approval. Valuable clinical application of these tests goes beyond diagnosis and includes risk assessment to identify allergic patients who are most sensitive and at risk for severe allergic reactions, and to define prognosis and assess clinical response to immunomodulatory treatments.

Peanut Can Be Used as a Reference Allergen for Hazard Characterization in Food Allergen Risk Management: A Rapid Evidence Assessment and Meta-Analysis

Regional and national legislation mandates the disclosure of “priority” allergens when present as an ingredient in foods, but this does not extend to the unintended presence of allergens due to shared production facilities. This has resulted in a proliferation of precautionary allergen (“may contain”) labels (PAL) that are frequently ignored by food-allergic consumers. Attempts have been made to improve allergen risk management to better inform the use of PAL, but a lack of consensus has led to variety of regulatory approaches and nonuniformity in the use of PAL by food businesses. One potential solution would be to establish internationally agreed “reference doses,” below which no PAL would be needed. However, if reference doses are to be used to inform the need for PAL, then it is essential to characterize the hazard associated with these low-level exposures. For peanut, there are now published data relating to over 3000 double-blind, placebo-controlled challenges in allergic individuals, but a similar level of evidence is lacking for other priority allergens. We present the results of a rapid evidence assessment and meta-analysis for the risk of anaphylaxis to a low-level allergen exposure for priority allergens. On the basis of this analysis, we propose that peanut can and should be considered an exemplar allergen for the hazard characterization at a low-level allergen exposure.

Latest Developments in the Management of Nut Allergies

Purpose of review

In this review, we sought to describe the most recent advances in the dietary and medical management of peanut and tree nut allergy, including selective introduction and immunotherapy.

Recent findings

Dietary updates include changes to labeling laws, improved information sources, and new apps for buying foods in shops and overseas to better protect individuals with nut allergies. There are still issues in the management of nut allergies in schools, such as parents having to resort to packed lunches instead of school meals and patients experiencing bullying. Air travel also poses concern, but additional resources are now available to travelers, and recent evidence suggest limited airborne exposure to nuts. The medical management of anaphylaxis is use of epinephrine; however, this remains underutilized. Needle length and administration devices have been recently debated considering the risk of bone penetration vs subcutaneous administration, and autoinjectors seem to deliver higher peak concentrations than syringes. Selective nut introduction has gained momentum in the last 5 years, demonstrating improved quality of life but with the need for motivated parents for continued consumption and available resources for challenges. Immunotherapy to nuts is also a rapidly developing field, with the balance of efficacy and safety being important considerations in the differing modes of administration.

Summary

The management of nut allergies is a rapidly developing field, and dietary and medical management have progressed significantly in the last 5 years. Future research directions include improving safety and efficacy of food immunotherapy and examining patients’ goals for therapy and treatment outcomes.

Addressing Common Misconceptions in Food Allergy: A Review

Background: Food allergies are common, affecting 1 in 13 school children in the United States and their prevalence is increasing. Many misconceptions exist with regards to food allergy prevention, diagnosis and management. Objective: The main objective of this review is to address misconceptions with regards to food allergies and discuss the optimal, evidence-based approach for patients who carry this diagnosis. Observations: Common misconceptions in terms of food allergy prevention include beliefs that breastfeeding and delayed introduction of allergenic foods prevent the development of food allergies. In terms of diagnosis, statements such as ‘larger skin prick tests or/and higher levels of food-specific IgE can predict the severity of food-induced allergic reactions’, or ‘Tryptase is always elevated in food-induced anaphylaxis’ are inaccurate. Additionally, egg allergy is not a contraindication for receiving the influenza vaccine, food-allergy related fatalities are rare and peanut oral immunotherapy, despite reported benefits, is not a cure for food allergies. Finally, not all infants with eczema will develop food allergies and epinephrine auto-injectors may unfortunately be both unavailable and underused in food-triggered anaphylaxis. Conclusions and relevance: Healthcare professionals must be familiar with recent evidence in the food allergy field and avoid common misunderstandings that may negatively affect prevention, diagnosis and management of this chronic disease.

Basophil activation test shows high accuracy in the diagnosis of peanut and tree nut allergy: The Markers of Nut Allergy Study

BACKGROUND

Peanut and tree nut allergies are the most important causes of anaphylaxis. Co-reactivity to more than one nut is frequent, and co-sensitization in the absence of clinical data is often obtained. Confirmatory oral food challenges (OFCs) are inconsistently performed.

OBJECTIVE

To investigate the utility of the basophil activation test (BAT) in diagnosing peanut and tree nut allergies.

METHODS

The Markers Of Nut Allergy Study (MONAS) prospectively enrolled patients aged 0.5-17 years with confirmed peanut and/or tree nut (almond, cashew, hazelnut, pistachio, walnut) allergy or sensitization from Canadian (n = 150) and Austrian (n = 50) tertiary pediatric centers. BAT using %CD63⁺ basophils (SSClow/CCR3pos) as outcome was performed with whole blood samples stimulated with allergen extracts of each nut (0.001-1000 ng/mL protein). BAT results were assessed against confirmed allergic status in a blinded fashion to develop a generalizable statistical model for comparison to extract and marker allergen-specific IgE.

RESULTS

A mixed effect model integrating BAT results for 10 and 100 ng/mL of peanut and individual tree nut extracts was optimal. The area under the ROC curve (AUROC) was 0.98 for peanut, 0.97 for cashew, 0.92 for hazelnut, 0.95 for pistachio, and 0.97 for walnut. The BAT outperformed sIgE testing for peanut or hazelnut and was comparable for walnut (AUROC 0.95, 0.94, 0.92) in a sub-analysis in sensitized patients undergoing OFC.

CONCLUSIONS

Basophil activation test can predict allergic clinical status to peanut and tree nuts in multi-nut-sensitized children and may reduce the need for high-risk OFCs in patients.

Improving Diagnostic Accuracy in Food Allergy

The diagnosis of food allergy can have a major impact on the lives of patients and families, imposing dietary restrictions and limitations on social activities. On the other hand, misdiagnosis can place the patient at risk of a potentially severe allergic reaction. Therefore, an accurate diagnosis of food allergy is of utmost importance. The diagnosis of food allergy is often established by the combination of the clinical history and allergen-specific IgE; however, without a clear history of an allergic reaction, the interpretation of IgE sensitization tests can be difficult. There are also rare cases of clinical food allergy in the absence of IgE sensitization. For that reason, testing for suspected food allergy ideally requires access to oral food challenges (OFCs), which are currently the gold standard tests to diagnose food allergy. As OFCs are time consuming and involve the risk of acute allergic reactions of unpredictable severity, the question remains: how can we improve the accuracy of diagnosis before referring the patient for an OFC? Herein, we review the predictive value of different tests used to support the diagnosis of food allergy, discuss implications for therapy and prognosis, and propose a diagnostic approach to be applied in clinical practice.

Identification of Pru du 6 as a potential marker allergen for almond allergy

BACKGROUND

Oral food challenges have demonstrated that diagnosis of almond allergy based on extract-sIgE tests displays low specificity. Molecular allergy diagnosis is expected to improve accuracy, but its value in diagnosing almond allergy remains unknown. The aim of this study was to identify relevant almond allergens and examine their ability to improve almond allergy diagnosis.

METHODS

IgE-reactive proteins were purified from almond kernels. IgE binding to almond extract and the allergens was analyzed by quantitative ELISA using sera from 18 subjects with a proven almond allergy. The control group consisted of sera from 18 subjects allergic to peanut and/or tree nuts but tolerant to almond.

RESULTS

Three IgE-binding proteins were identified: legumin (Pru du 6), alpha-hairpinin (Pru du 8), and mandelonitrile lyase (Pru du 10). Positive IgE (≥0.35 kU/L) to almond extract showed 94% sensitivity but only 33% specificity. IgE to Pru du 6 maintained high sensitivity (83%) and provided superior specificity (78%). Sera from almond-allergic subjects had significantly higher IgE levels to almond extract (P < .0001) and Pru du 6 (P < .0001) than sera from tolerant donors. Sensitization to Pru du 6 was highly specific for almond allergy, while frequencies of sensitization to legumins from peanut, walnut, hazelnut, and cashew were similar in both groups. IgE to Pru du 8 and Pru du 10 was less sensitive (41% and 67%), but showed specificities of 100% and 61%.

CONCLUSION

The use of almond allergens markedly increases the diagnostic specificity compared to the extract. Pru du 6 is a potential new molecular marker for almond allergy.

Dietary Management of Food Allergy

Worldwide food allergy prevalence is increasing, especially in children. Food allergy management strategies include appropriate avoidance measures and identifying suitable alternatives for a nutritionally sound diet. Individualized dietary intervention begins teaching label reading, which differs among countries or regions. Dietary intervention must result in a nutritionally sound plan including alternatives to support optimal growth and development. Inappropriate or incomplete dietary advice may increase the risk of adverse reactions, growth faltering, and nutrient deficiencies. Evidence indicates input from a registered dietitian improves nutritional outcomes. Nutritional input plays a critical role managing nutritional disorders related to food allergy.

Update on food allergy

Food allergy is a major public health issue with growing prevalence in the urbanized world and significant impact on the lives of allergic patients and their families. Research into the risk factors that have contributed to this increase and their underlying immune mechanisms could lead us to definitive ways for treatment and prevention of food allergy. For the time being, introduction of peanut and other allergenic foods in the diet at the time of weaning seems to be an effective way to prevent the development of food allergy. Improved diagnosis and appropriate management and support of food allergic patients are central to patient care with food immunotherapy and biologics making the transition to clinical practice. With the new available treatments, it is becoming increasingly important to include patients' and family preferences to provide a management plan tailored to their needs.

The global burden of illness of peanut allergy: A comprehensive literature review

Peanut allergy (PA) currently affects approximately 2% of the general population of Western nations and may be increasing in prevalence. Patients with PA and their families/caregivers bear a considerable burden of self‐management to avoid accidental peanut exposure and to administer emergency medication (adrenaline) if needed. Compared with other food allergies, PA is associated with higher rates of accidental exposure, severe reactions and potentially fatal anaphylaxis. Approximately 7%–14% of patients with PA experience accidental peanut exposure annually, and one‐third to one‐half may experience anaphylaxis, although fatalities are rare. These risks impose considerably high healthcare utilization and economic costs for patients with PA and restrictions on daily activities. Measures to accommodate patients with PA are often inadequate, with inconsistent standards for food labelling and inadequate safety policies in public establishments such as restaurants and schools. Children with PA are often bullied, resulting in sadness, humiliation and anxiety. These factors cumulatively contribute to significantly reduced health‐related quality of life for patients with PA and families/caregivers. Such factors also provide essential context for risk/benefit assessments of new PA therapies. This narrative review comprehensively assessed the various factors comprising the burden of PA.