Dietary management of peanut and tree nut allergy: what exactly should patients avoid?

Dietary management of IgE and non-IgE-mediated food allergies in pediatric patients

Food allergies (FA) consist of both IgE and non-IgE-mediated entities, with varying phenotypes and overlapping and different considerations for each specific disease presentation. In general, all FAs place children at increased risk for inadequate nutritional intake and negative impacts on their nutritional status, as well as negative impacts on the quality of life for the entire family. To minimize these untoward effects, a multidisciplinary approach should be taken, including consultation and management with a dietitian trained in the varying presentations of FA. Families should be instructed on label reading as a first line of nutritional management. During a nutrition consultation, the age of the child, growth, and nutritional status should be considered. Food refusal should be assessed and addressed. Families should be educated on avoidance and appropriate substitutions. In the case of cow's milk allergy, a suitable specialized formula should be suggested if the infant is not breastfed or if breast milk supply is not sufficient. Other mammalian milk should be avoided and careful consideration should be given before plant-based milk is used in young children. Specific food allergies may differ in terms of advice provided on the level of avoidance required, whether precautionary advisory labels should be avoided, and if a maternal avoidance of the allergen during breastfeeding should be advised. The role of immunonutrition on overall health should be discussed.

Precautionary Allergen Labeling: Avoidance for All?

PURPOSE OF REVIEW

Precautionary allergen labeling (PAL) suggests the risk of unintended allergen presence (UAP) in food but is unregulated in most countries and inconsistently applied by food manufacturers. This review evaluates the current use of PAL, its relevance to allergic consumers, and weighs possible advantages and disadvantages of avoiding products with PAL.

RECENT FINDINGS

In most countries, manufacturers are free to decide whether, when, and how to apply PAL resulting in inconsistencies and consumer confusion. Patients with food allergy often interpret PAL incorrectly and without guidance from their health care providers. Health care providers are also prone to misinterpreting PAL, indicating a need for better education. Consumers desire guidance on whether to avoid products with PAL or not. Until further regulatory guidance is available, shared decision-making between patient and provider is required to offer individualized, rather than one-size-fits-all, approaches to PAL.

Oat-based milk alternatives: the influence of physical and chemical properties on the sensory profile

Introduction

Oat-based milk alternatives (OMAs) have become increasingly popular, perhaps due to their low allergenicity and preferred sensory attributes when compared to other milk alternatives. They may also provide health benefits from unique compounds; avenanthramides, avenacosides, and the dietary fibre beta-glucan. This has led to a variety of commercial options becoming available. Being a fairly new product, in comparison to other plant-based milk alternatives (PBMAs), means little research has been undertaken on the sensory profile, and how it is influenced by the physical and chemical properties.

Methods

This study investigated the sensory, physical and chemical profiles of current commercially available OMAs, that varied in fortification, use of stabilisers, and oat content. The volatile compounds and their respective aromas were analysed using solid phase microextraction followed by gas chromatography mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Liquid chromatography mass spectrometry (LC-MS) was used for identification of avenanthramides and avenacosides. Particle size and polydispersity index (PDI) were analysed using a Mastersizer and Zetasizer, respectively, with colour analysis carried out using a colourimeter, and viscosity measurements using a rheometer. Descriptive sensory profiling was used to assess the impact on the sensory characteristics of the different samples and the sensory data acquired were correlated with the instrumental data.

Results

Samples with smaller particle size appeared whiter-both instrumentally and perceptually. The only clear plastic packaged product differed substantially in volatile profile from all other products, with a higher abundance of many volatile compounds, and high overall perceived aroma. Avenanthramides and avenacosides were present in all samples, but differed significantly in abundance between them.

Discussion

The results suggested smaller particle size leads to whiter colour, whilst differences in processing and packaging may contribute to significant differences in aroma. Astringency did not differ significantly between samples, suggesting that the variation in the concentrations of avenacosides and avenanthramides were below noticeable differences.

Preventing food allergy fatalities

Fatal anaphylaxis to food is thankfully rare, but every death is a potentially avoidable tragedy. Usually, there will be a coronial inquest to establish the 'how and why' for each death. Reviewing these food allergy-related deaths identifies a number of common themes and risk factors. While some are non-modifiable (such as age, gender and ethnicity), others are and include delayed epinephrine administration and communication difficulties in allergen avoidance. This review highlights the key messages in food allergy-related fatality prevention for healthcare professionals and patients alike, and where available, we explain the evidence behind such recommendations. We describe the data behind the good practice points to facilitate their adoption in routine practice without generating additional anxiety for what is a comparatively rare event. We also propose an information leaflet for patients and carers, developed with patients and endorsed by two major allergy charities, to facilitate dissemination of the recommendations in this review.

Nutritional Management of Children with Food Allergies

Purpose of the Review

The purpose of the review is to review the evidence for the nutritional management of paediatric food allergy and provide a practical approach for healthcare professionals working in this area.

Recent Findings

Dietary elimination remains the mainstay for management of food allergies in children. However, the elimination of food allergens increases the risk for growth faltering, micronutrient deficiencies and feeding difficulties. Breastmilk remains the ideal source of nutrition for infants, but when not available, the vast majority will tolerate an extensively hydrolysed formula, and rice hydrolysate has also been suggested as a suitable alternative. Only in severe cases, including anaphylaxis, eosinophilic oesophagitis and growth faltering, is an amino acid formula indicated. The early introduction of peanut and egg and avoiding the delay in the introduction of other allergens, when not already allergic, has been highlighted by recent studies.

Summary

Whilst the elimination of allergens increases the risk of developing poor growth, micronutrient deficiencies and feeding difficulties, optimal, early dietary input, including advice on active introduction of allergens and alternative feeds, ideally from a registered dietitian/nutritionist, may be prevent and improve outcomes.

[Role of vegan diets in food allergies-risk of developing food anaphylaxis?]

We report about a 28-year-old woman with an anaphylactic reaction to falafel. The diagnosis of type 1 allergy to peas was made based on the detailed medical history, the sensitization profile and an oral food challenge. Pea (Pisum sativum) is a legume that is increasing used, for example, as protein flour in vegetarian and vegan food products. In addition to the case report, we discuss the anaphylaxis risk of food used in the vegan diet.

Tree nut introduction in a peanut-allergic child: To eat, to screen, or to avoid?

There is no defined standard of care around tree nut introduction in a peanut-allergic child, and the role of screening prior to tree nut introduction is controversial. There is some evidence that peanut-allergic children are at increased risk of tree nut allergy, with approximately 23-68% of children with co-existent peanut/tree nut allergy. In some studies, it has been shown that tree nut allergy in children has the potential to be a severe allergy. However, this appears to be age-specific as infant anaphylaxis in general tends to be milder, and there has been no fatality reported on the first ingestion of an allergen in infancy. Familial hesitancy has been identified as a possible condition for undertaking screening tests prior to allergen introduction. Indeed, there has been limited evidence that caregiver hesitancy may exist in peanut-allergic families with tree nut introduction. However, pre-emptive screening has the potential to overdiagnose tree nut allergy and delay introduction (which could paradoxically increase risk). As a result, the decision is best made in the context of shared decision-making and patient preference-sensitive care.

White paper on peanut allergy - part 1: Epidemiology, burden of disease, health economic aspects

Peanuts are Leguminosae, commonly known as the legume or pea family, and peanut allergy is among the most common food allergies and the most common cause of fatal food reactions and anaphylaxis.

The prevalence of peanut allergy increased 3.5-fold over the past two decades reaching 1.4–2% in Europe and the United States. The reasons for this increase in prevalence are likely multifaceted. Sensitization via the skin appears to be associated with the development of peanut allergy and atopic eczema in infancy is associated with a high risk of developing peanut allergy.

Until recently, the only possible management strategy for peanut allergy was strict allergen avoidance and emergency treatment including adrenaline auto-injector in cases of accidental exposure and reaction.

This paper discusses the various factors that impact the risks of peanut allergy and the burden of self-management on peanut-allergic children and their caregivers.

AAAAI Work Group Report: Trends in Oral Food Challenge Practices Among Allergists in the United States

The oral food challenge (OFC) is the criterion standard for diagnosing food allergy, but prior studies indicate many allergists may not be using OFCs for various reasons. To better understand current OFC trends, practices, and barriers, the American Academy of Allergy Asthma and Immunology (AAAAI) Adverse Reactions to Foods Committee subcommittee updated a 19-item survey (previously administered in 2009) and sent it to AAAAI and American College of Allergy, Asthma, and Immunology (ACAAI) membership. There were a total of 546 respondents who represented approximately a 10% response rate. Among the 546 respondents, compared with 2009, significantly more providers offer OFCs (95% vs 84.5%), offer >10 OFCs per month (17% vs 5.6%), obtain informed consent (82.2% vs 53.6%), and performed OFCs in fellowship (71% vs 45%) (all P < .001). Fellowship OFC training was limited, with 56% performing <10 OFCs in fellowship and 29% performing none. Although 94% see patients <12 months of age, 35.5% do not offer OFCs for early peanut introduction. Although 79% dedicate a supervising medical provider (MD, NP, PA) and 86% have a written OFC protocol, only 60% had a standardized reaction treatment protocol and 56% prepared emergency medications before OFC. Compared with 2009, there was significant worsening of perceived barriers to performing OFCs, including time (65.6% vs 55%), space (55.3% vs 27.1%), staffing (59.6% vs 44.3%), experience (16.9% vs 11.5%), and hospital proximity (10.9% vs 7.9%), though reimbursement as a barrier improved (45.9% vs 53.7%) (all P < .01). Compared with 2009, although more providers offer OFCs, multiple perceived barriers to performing OFCs have worsened. Hesitancy to challenge infants and emergency preparedness issues are emerging potential concerns.

Food anaphylaxis in the United Kingdom: analysis of national data, 1998-2018

OBJECTIVE

To describe time trends for hospital admissions due to food anaphylaxis in the United Kingdom over the past 20 years.

DESIGN

Analysis of national data, 1998-2018.

SETTING

Data relating to hospital admissions for anaphylaxis and deaths, and prescription data for adrenaline autoinjector devices.

PARTICIPANTS

UK population as a whole and devolved nations (England, Scotland, Wales, and Northern Ireland).

MAIN OUTCOME MEASURES

Time trends, age, and sex distributions for hospital admissions for anaphylaxis due to food and non-food triggers, and how these admission rates compare with the case fatality rate (number of fatalities as a proportion of hospital admissions).

RESULTS

Between 1998 and 2018, 101 891 people were admitted to hospital for anaphylaxis. Of these admissions, 30 700 (30.1%) were coded as due to a food trigger. Food anaphylaxis admissions increased from 1.23 to 4.04 per 100 000 population per year (from 1998 to 2018), an annual increase of 5.7% (95% confidence interval 5.5% to 5.9%, P<0.001). The largest increase in hospital admissions was observed in children younger than 15 years, with an increase from 2.1 to 9.2 admissions per 100 000 population per year (an annual increase of 6.6%, 95% confidence interval 6.3% to 7.0%). For comparison, the annual increase was 5.9% (5.6% to 6.2%) in people aged 15-59 years and 2.1% (1.8% to 3.1%) in those aged 60 years and older. 152 deaths were identified where the fatal event was probably caused by food induced anaphylaxis. The case fatality rate decreased from 0.7% to 0.19% for confirmed fatal food anaphylaxis (rate ratio 0.931, 95% confidence interval 0.904 to 0.959, P<0.001) and to 0.30% for suspected fatal food anaphylaxis (0.970, 0.945 to 0.996, P=0.024). At least 46% (86 of 187, which also includes 35 deaths in 1992-98) of deaths were triggered by peanut or tree nut. Cow's milk was responsible for 17 of 66 (26%) deaths in school aged children. Over the same time period, prescriptions for adrenaline autoinjectors increased by 336% (estimated rate ratio 1.113, 95% confidence interval 1.112 to 1.113; an increase of 11% per year).

CONCLUSIONS

Hospital admissions for food induced anaphylaxis have increased from 1998 to 2018, however the case fatality rate has decreased. In school aged children, cow's milk is now the most common single cause of fatal anaphylaxis.

A Food, a Bite, a Sip: How Much Allergen Is in That?

Detailed information about the amount of allergenic protein ingested by the patient prior to an allergic reaction yields valuable information for the diagnosis, guidance and management of food allergy. However, the exact amount of ingredients is often not declared on the label. In this study the feasibility was studied for estimating the amount of allergenic protein from milk, eggs, peanuts and hazelnuts in frequently consumed composite and non-composite foods and per bite or sip size in different age groups in the Netherlands. Foods containing milk, egg, peanut or hazelnut most frequently consumed were selected for the age groups 2–3, 4–6 and 19–30 years. If the label did not yield clear information, the amount of allergenic protein was estimated based on food labels. Bite or sip sizes were determined in these age groups in 30 different foods. The amount of allergenic protein could be estimated in 47/70 (67%) of composite foods, which was complex. Estimated protein content of milk, egg, peanut and hazelnut was 2–3 g for most foods but varied greatly from 3 to 8610 mg and may be below threshold levels of the patient. In contrast, a single bite or sip can contain a sufficient amount of allergenic protein to elicit an allergic reaction. Bite and sip sizes increased with age. In every day practice it is hard to obtain detailed and reliable information about the amount of allergenic protein incorporated in composite foods. We encourage companies to disclose the amount of common allergenic foods on their labels.

Recent advances in the management of nut allergy

Peanut/tree nut allergy is common and has been associated with particularly severe reactions. Epidemiological data have shown that the prevalence ranges between 0.05% and 4.9% for tree nut and between 0.5% and 3% for peanut. These large variations can be explained by differences in the age of included patients and the geographical region. In addition, the food consumption modality (ie, raw versus roasted) plays a major role, as heat treatment has the capacity to modify the allergenicity of nuts and legumes. Nut allergies tend to persist into adulthood and consequently have a high impact on quality of life.

Recently, it has been demonstrated that a significant proportion of nut allergic patients are able to tolerate other nuts. As opposed to the avoidance of all nuts, this approach is currently proposed in several tertiary allergy centers. However, diagnosis of nut allergy is particularly difficult due to co-sensitization leading to high rate of false positive skin prick tests and/or specific IgE to whole allergen extracts. The use of component resolved diagnosis leads to major improvement of diagnosis, particularly to distinguish between primary and secondary nut allergies. The basophil activation test has been suggested to be useful but is still used mainly as a research tool. Thus, diagnosis remains mainly based on the oral food challenge, which is considered as the gold standard.

Regarding treatment, avoidance remains the cornerstone of management of nut allergy. Oral immunotherapy is increasingly proposed as an alternative management strategy.

Cow's milk allergy prevention

OBJECTIVE

Scoping review on IgE-mediated cow's milk allergy prevention.

DATA SOURCES

Literature search of PubMed database and gray literature.

STUDY SELECTIONS

Peer-reviewed relevant observational and randomized controlled studies in the pediatric population in the English language were selected and reviewed.

RESULTS

There is increasing literature supporting the role of early and ongoing cow's milk ingestion in the prevention of cow's milk allergy. The studies supporting a preventive role with early cow's milk ingestion suggest cow's milk introduction at a very early age (most within the first month of life), suggesting the possibility of a different mechanism of sensitization than other common allergens. It is possible that gut colonization and the diversity and intensity of microbial exposure may play a role in inducing cow's milk tolerance. It is also possible that vitamin D may have a role in modulating those immune functions.

CONCLUSION

Further research regarding the role that early cow's milk ingestion plays in the prevention of cow's milk allergy is required, and questions remain. The absolute amount required for tolerance is unclear. Studies in higher risk populations are required. However, there is an intriguing and increasingly more pervasive association between early ongoing cow's milk ingestion and cow's milk allergy prevention.

Basophil Activation Test Reduces Oral Food Challenges to Nuts and Sesame

BACKGROUND

Nut allergic patients are often IgE sensitized to other nuts/seeds and need multiple oral food challenges (OFCs) before the safe nuts can be introduced in the diet. However, OFCs are time-consuming and risky procedures.

OBJECTIVE

To assess the utility of the basophil activation test (BAT) to predict the allergic status and reduce the need for an OFC in children with 1 or more nut or seed allergies.

METHODS

Participants in the Pronuts study recruited at the Geneva and the London centers were tested on the BAT to hazelnut, cashew nut, sesame, almond, and peanut, Ara h 1, Ara h 2, Ara h 6, using FlowCAST, a commercially available BAT kit, and flow cytometry.

RESULTS

The BAT to hazelnut, cashew nut, sesame, almond, and peanut discriminated between allergic and nonallergic children, to the respective nut or seed. The optimal allergen concentration and their optimal, positive, and negative cutoffs were identified for the BAT and the other tests, for each nut and seed. Using the BAT as a second step in the diagnostic process, after equivocal skin prick test and IgE to extracts and components, reduced the number of total OFCs by 5% to 15% and positive OFCs by 33% to 75% (except for hazelnut) with 0% false-negatives and a diagnostic accuracy of 96% to 100%.

CONCLUSION

The BAT proved to be a useful diagnostic tool, used in a stepwise approach, to predict the allergic status and reduce the number of OFCs in the Pronuts study participants with at least 1 nut allergy willing to consume selected nuts.

Can my child with IgE-mediated peanut allergy introduce foods labeled with "may contain traces"?

Peanut IgE-mediated food allergy is one of the most common food allergies in children with a prevalence that has increased in the past decades in Westernized countries. Peanut allergies can trigger severe reactions and usually persist over time. Peanut-allergic children and their families are often confronted to processed foods with precautionary allergen labeling (PAL) such as "may contain traces of peanuts," which are frequently used by the food industry. Patients are generally confused as to whether eating such foods entails a risk of allergic reaction, which can ultimately lead to dietary restrictions and decreased quality of life. Thus, guidance toward eviction of foods with PALs such as "may contain traces of peanuts" is a recurring problem that peanut-allergic patients address during pediatric allergy consultations with varying attitudes among allergists. Many studies have evaluated peanut contamination in foods with PALs, with generally less than 10% of foods containing detectable levels of peanuts, albeit heterogeneous amounts, with in rare occasions levels that could trigger allergic reactions in certain patients. The risk of reacting to foods with traces varies significantly with threshold, with patients with the lowest reaction thresholds at highest risk, and a dramatic reduction of risk as threshold increases. Thus, risk stratification based on individual reaction threshold may help stratify patients' risk of reacting to foods with PAL. In clinical practice, a single-dose 30 mg peanut protein oral food challenge may be an option to stratify peanut-allergic patients' risk when introducing foods with PAL, as illustrated by three clinical cases.

Management of Peanut Allergy

Peanut allergy is a growing public health concern in westernized countries. Peanut allergy is characterized as an often severe and lifelong allergy, which can have detrimental effects on quality of life and trigger anxiety. Although multiple therapeutic options are emerging, the focus of current management strategies is strict peanut avoidance and carriage of self-injectable epinephrine. The greatest risk of reacting to peanut comes from direct ingestion, whereas casual skin contact or airborne exposure is highly unlikely to provoke significant symptoms. Patients and families must be educated about how to best execute strict peanut avoidance through careful label reading as well as how to understand and address likely and unlikely risk with regard to peanut exposure in public, in particular when dining outside of the home and for children attending school or child care. This review discusses the risk of exposure in public such as at school or on an airplane and how such risk can be abated, situations and scenarios when dining out of the house that may pose more risks than others, the essentials of US and EU label reading laws with particular emphasis on precautionary labeling and the risk implied by such, quality of life and psychosocial issues that may affect the peanut allergic individual and family, and a discussion of how risk may differ and evolve based on the patient's age.

Veganism and paediatric food allergy: two increasingly prevalent dietary issues that are challenging when co-occurring

Vegan diets – defined as the exclusion of all foods of animal origin from the diet- are becoming popular. In recent years, the prevalence of food allergy has also increased, and disproportionately affects children. When vegan diets and food allergy co-occur, this combination can be challenging and pose risks of nutritional deficiencies, particularly during childhood. In this paper, we aim to summarise the major concerns regarding vegan diets and food allergy, review the literature on this topic, and provide some suggestions for healthcare providers, particularly dietitians and nutritionists, who work with food allergic, vegan patients and their family. When working with this patient population, a regular and complete medical nutrition history, including screening for any possible nutritional deficiencies, is warranted. Likewise, the routine tracking of serum markers (especially iodine, iron, zinc, calcium, Vitamins B12, D, B2, and A, selected n-3 fatty acids and protein, which are more abundant in animal vs. plant foods) and symptoms of co-morbid diseases, including asthma, is important, as comorbid diseases may increase energy and nutrient requirements. For infants and children, anthropometry ought to be tracked longitudinally at regular intervals to identify any deviations from the child’s previous growth pattern, and to accommodate any increased requirements for growth and development. Correct diagnoses, education and allergy management must be disseminated to the family in a clear and appropriate manner. Children with allergy may have increased nutritional needs due to comorbidity. This is complicated by coincident food allergy and vegan diet as both impose diet restrictions (limiting sources of important nutrients, need for dietary variety and/or increased consumption due to reduced bioavaliability).

Real-world tree nut consumption in peanut-allergic individuals

BACKGROUND

Individuals with peanut allergy often avoid tree nuts, yet true rates of tree nut allergy in peanut-allergic individuals are as low as 7%.

OBJECTIVE

To examine tree nut sensitization patterns in peanut-allergic individuals, patient and family choice regarding tree nut consumption, and factors that influence consumption of tree nuts.

METHODS

All patients presenting for peanut allergy evaluation to an outpatient allergy office were included during a 4-month period. In addition to demographic information, sensitization to tree nuts and tree nut consumption were collected. Logistic regression was performed to generate odds ratios with 95% CIs in univariate and multivariate analyses for variables that predict tree nut consumption.

RESULTS

A total of 258 individuals with peanut allergy were enrolled. Ninety-five (36.8%) consumed all tree nuts ad libitum, 63 (24.4%) consumed some but not all tree nuts, and 100 (38.8%) consumed no tree nuts. Of the 100 electively avoiding all tree nuts, the most commonly reported reason was fear of cross-contact (50%). Although there was no difference between rates of sensitization between individual tree nuts (P = .056), cashew and pistachio had higher serum specific IgE levels compared with other tree nuts (P < .001). The tree nut most commonly consumed by peanut-allergic individuals was almond (P < .001). Consumption of foods with precautionary labeling was the strongest predictor of tree nut consumption in peanut allergic individuals (P < .001) CONCLUSION: Our data highlight the potential for safe introduction of tree nuts in peanut-allergic individuals and indicate that peanut-allergic individuals who consume foods with precautionary labeling are most likely to consume tree nuts.

Can Nuts Mitigate Malnutrition in Older Adults? A Conceptual Framework

The proportion of adults aged over 60 years in the world is expected to reach 20% by the year 2050. Ageing is associated with several physiological changes that increase the risk of malnutrition among this population. Malnutrition is characterized by deficiencies or insufficiencies of macro- and micronutrients. Malnutrition has detrimental effects on the health, wellbeing, and quality of life in older adults. Nuts are rich in energy, unsaturated fats, and protein, as well as other nutrients that provide a range of health benefits. While the effects of nuts on overnutrition have been studied extensively, very few studies have been specifically designed to understand the role of nuts in mitigating undernutrition in the elderly. Therefore, this review explores the potential role of nuts in improving the nutritional status of older adults who are at risk of undernutrition. Several properties of whole nuts, some of which appear important for addressing overnutrition, (e.g., hardness, lower-than-expected nutrient availability, satiety-enhancing effects) may limit their effectiveness as a food to combat undernutrition. However, we propose that modifications such as transforming the physical form of nuts, addressing the timing of nut ingestion, and introducing variety may overcome these barriers. This review also discusses the feasibility of using nuts to prevent and reverse undernutrition among older adults. We conclude with a recommendation to conduct clinical studies in the future to test this conceptual framework.

BSACI guideline for the diagnosis and management of peanut and tree nut allergy

Peanut nut and tree nut allergy are characterised by IgE mediated reactions to nut proteins. Nut allergy is a global disease. Limited epidemiological data suggest varying prevalence in different geographical areas. Primary nut allergy affects over 2% of children and 0.5% of adults in the UK. Infants with severe eczema and/or egg allergy have a higher risk of peanut allergy. Primary nut allergy presents most commonly in the first five years of life, often after the first known ingestion with typical rapid onset IgE-mediated symptoms. The clinical diagnosis of primary nut allergy can be made by the combination of a typical clinical presentation and evidence of nut specifc IgE shown by a positive skin prick test (SPT) or specific IgE (sIgE) test. Pollen food syndrome is a distinct disorder, usually mild, with oral/pharyngeal symptoms, in the context of hay fever or pollen sensitisation, which can be triggered by nuts. It can usually be distinguish clinically from primary nut allergy. The magnitude of a SPT or sIgE relates to the probability of clinical allergy, but does not relate to clinical severity. SPT of ≥ 8 mm or sIgE ≥ 15 KU/L to peanut is highly predictive of clinical allergy. Cut off values are not available for tree nuts. Test results must be interpreted in the context of the clinical history. Diagnostic food challenges are usually not necessary but may be used to confirm or refute a conflicting history and test result. As nut allergy is likely to be a long-lived disease, nut avoidance advice is the cornerstone of management. Patients should be provided with a comprehensive management plan including avoidance advice, patient specific emergency medication and an emergency treatment plan and training in administration of emergency medication. Regular re-training is required.

Component-resolved diagnostics demonstrates that most peanut-allergic individuals could potentially introduce tree nuts to their diet

BACKGROUND

Nut allergy varies from pollen cross-allergy, to primary severe allergy with life-threatening symptoms. The screening of IgE antibodies to a wide spectrum of allergens, including species-specific and cross-reactive allergens, is made possible via microarray analysis.

OBJECTIVE

We sought to study the association of variable IgE sensitization profiles to clinical response in peanut-challenged children and adolescents in a birch-endemic region. In addition, we studied the avoidance of tree nuts and species-specific sensitizations.

METHODS

We studied 102 peanut-sensitized patients who underwent a double-blind placebo-controlled challenge to peanut. We analysed ISAC ImmunoCAP microarray to 112 allergens, singleplex ImmunoCAPs for hazelnut Cor a 14 and cashew Ana o 3, and performed skin prick tests to peanut, tree nuts and sesame seed. We surveyed avoidance diets with a questionnaire.

RESULTS

Sensitization to PR-10 proteins was frequent (Bet v 1 90%), but equally high in the challenge negatives and positives. IgE to Ara h 2 and Ara h 6 discriminated peanut allergic (n = 69) and tolerant (n = 33) the best. Avoidance of tree nuts was common (52% to 96%), but only 6% to 44% presented species-specific sensitizations to tree nuts, so a great number could potentially introduce these species into their diet.

CONCLUSIONS AND CLINICAL RELEVANCE

PR-10-sensitizations were frequent and strong regardless of peanut allergy status. Component-resolved diagnostics can be employed to demonstrate to patients that sensitization to seed storage proteins of tree nuts is uncommon. Several tree nuts could potentially be reintroduced to the diet.

Elimination diet and the development of multiple tree-nut allergies

BackgroundDespite its high prevalence, relatively little is known about the characteristics of patients with multiple tree-nut allergies.MethodsPatients (n=60, aged 4-15 years), recruited for a multiple food (tree nuts, peanut, milk, egg, soy, sesame, and wheat) oral immunotherapy (OIT) study, filled a questionnaire on their initial allergy evaluation. Medical records were reviewed. At OIT enrollment (median interval, 7.5 years), patients underwent oral food challenges (OFCs) to foods still eliminated.ResultsThere was significantly less evidence for eliminating tree nuts compared with other foods, as reflected by a lower rate of acute reaction to the offending food, either as the trigger for initial allergy evaluation (5.9% for tree-nuts vs. 20-40% for other foods, respectively P<0.001) or later in life (14.5% vs. 38-75%, respectively P=0.001), and a higher rate of negative skin prick test (SPT)/specific IgE (sIgE) at initial diagnosis (25% vs. <10%, P<0.001). SPT/sIgE increased significantly from past initial levels to present for tree nuts (P<0.001) and peanut (P=0.001) but not for other foods, and most OFCs performed at present were positive.ConclusionsTree nuts are often eliminated from the diet of multiple-food-allergic patients, despite their low probability for allergy. Sensitization and allergy to most tree nuts exist years later, suggesting that it developed during the period of elimination.

The Role of Nutritional Aspects in Food Allergy: Prevention and Management

The prevalence of food allergy in childhood appears to be increasing in both developed and transitional countries. The aim of this paper is to review and summarise key findings in the prevention and management of food allergy, focusing on the role of dietary components and nutritional habits in the development and optimal functioning of the immune system. Essential fatty acids, zinc and vitamin D are likely to enhance the anti-inflammatory and antioxidative barrier and promote immunologic tolerance. Additionally, nutritional components such as pre- and probiotics represent a novel research approach in the attempt to induce a tolerogenic immune environment. For all these reasons, the traditional avoidance diet has been, in recent years, completely reconsidered. New findings on the protective effect of an increased diversity of food introduced in the first year of life on allergic diseases are consistent with the hypothesis that exposure to a variety of food antigens during early life might play a role in the development of immune tolerance. Accordingly, therapeutic (and even preventive) interventions should be planned on an individual basis.

An update on the impact of food allergy on anxiety and quality of life

PURPOSE OF REVIEW

Food allergies have become more common, and management involves dietary avoidance that can impair quality of life. Patients and families must manage the daily risk of anaphylaxis at each meal. The purpose of this review is to describe the impact of food allergies on quality of life and to provide an update on new developments in food allergy management, particularly peanut allergy.

RECENT FINDINGS

Food allergy requires careful avoidance of common and ubiquitous dietary allergens. Living with food allergy is associated with annual economic costs in excess of $4000 per child, in addition to risks of anxiety and depressive symptoms. An expert panel sponsored by the 2017 National Institute of Allergy and Infectious Diseases published addendum guidelines for the prevention of peanut allergy, which suggest three separate approaches to peanut protein introduction for infants at various levels of risk.

SUMMARY

Clinicians must be aware of underappreciated burdens faced by children and families with food allergies. Management involves a partnership between primary and specialty care. Mitigation strategies to improve quality of life for patients include efforts to avoid overdiagnosis in synergy with balanced counseling about the risks of food allergies. Experimental food allergen desensitization can improve quality of life but remains investigational at this time. For patients with significant anxiety, interdisciplinary management involving professional counseling may be helpful. Risk stratification and early introduction of peanut protein can help prevent the development of peanut allergy.

Learning to Detect Triggers of Airway Symptoms: The Role of Illness Beliefs, Conceptual Categories and Actual Experience with Allergic Symptoms

Background: In asthma and allergic rhinitis, beliefs about what triggers allergic reactions often do not match objective allergy tests. This may be due to insensitivity for expectancy violations as a result of holding trigger beliefs based on conceptual relationships among triggers. In this laboratory experiment, we aimed to investigate how pre-existing beliefs and conceptual relationships among triggers interact with actual experience when learning differential symptom expectations.

Methods: Healthy participants (N = 48) received information that allergic reactions were a result of specific sensitivities versus general allergic vulnerability. Next, they performed a trigger learning task using a differential conditioning paradigm: brief inhalation of CO₂ enriched air was used to induce symptoms, while participants were led to believe that the symptoms came about as a result of inhaled allergens (conditioned stimuli, CS’s; CS+ followed by symptoms, CS- not followed by symptoms). CS+ and CS- stimuli either shared (e.g., birds-mammals) or did not share (e.g. birds-fungi) category membership. During Acquisition, participants reported symptom expectancy and symptom intensity for all triggers. During a Test 1 day later, participants rated symptom expectancies for old CS+/CS- triggers, for novel triggers within categories, and for exemplars of novel trigger categories. Data were analyzed using multilevel models.

Findings: Only a subgroup of participants (n = 22) showed differences between CO₂ and room air symptoms. In this group of responders, analysis of symptom expectancies during acquisition did not result in significant differential symptom CS+/CS- acquisition. A retention test 1 day later showed differential CS+/CS- symptom expectancies: When CS categories did not share category membership, specific sensitivity beliefs improved retention of CS+/CS- differentiation. However, when CS categories shared category membership, general vulnerability beliefs improved retention of CS+/CS- differentiation. Furthermore, participants showed some selectivity in generalization of symptom expectancies to novel categories, as symptom expectancies did not generalize to novel categories that were unrelated to CS+ or CS- categories. Generalization to novel categories was not affected by information about general vulnerability or specific sensitivities.

Discussion: Pre-existing vulnerability beliefs and conceptual relationships between trigger categories influence differential symptom expectancies to allergic triggers.

Peanut-allergic patients in the MIRABEL survey: characteristics, allergists' dietary advice and lessons from real life

BACKGROUND

The MIRABEL survey is an observational study on peanut allergy in France, Belgium and Luxemburg. The objectives are to provide data on a large population, to analyse the consumer behaviour, to study the presence of peanut traces in pre-packed foods with/without precautionary allergen labelling (PAL), and to combine these data to quantify allergic risk and produce a cost/benefit analysis. This paper reports a real-life observatory of 785 patients (< 16y: 86%): medical characteristics, eliciting doses (ED) in real life and in oral food challenges (OFC), factors associated with severe reactions, allergist dietary advice and patients' anxiety regarding their allergy.

METHODS

Age and symptoms at diagnosis, route of exposure, comorbidities, allergy tests, ED (OFC/real life; mg peanut protein), dietary advice about PAL, and anxiety score were recorded.

RESULTS

Median age was 3 years; 85% were declared allergic. Severe/potentially severe reactions were reported in 30% of the allergic patients: serious systemic reaction (15%), laryngeal angioedema (8%), shock (4%) and acute asthma (3%); 66% had atopic dermatitis, 58% asthma. Median ara h 2 sIgE level was 11.5 kUA/L. Of the 278 OFCs, 225 were positive (median ED: 67.3 mg). Real-life ED was < 100 mg in 44.3%. Severe reactions were significantly more frequent in teenagers and adults (P = 0.004), asthmatic patients (P = 0.033), and patients who reacted to inhalation (P < 0.001). No significant association was found for OFC ED or ara h 2 sIgE. Factors associated with strict avoidance advice including PAL were OFC ED < 100 mg (P < 0.001), but not severe reaction history (P = 0.051) or asthma (P = 0.34). Anxiety was significantly associated with strict avoidance (P < 0.001).

CONCLUSION AND CLINICAL RELEVANCE

Severe/potentially severe reactions, allergic comorbidities, and low EDs in real life are frequent in peanut-allergic patients. Asthma, teenage/adulthood and reaction to inhalation are associated with severe symptoms. PAL and criteria guiding dietary advice need to be improved.

Can we identify patients at risk of life-threatening allergic reactions to food?

Anaphylaxis has been defined as a 'severe, life-threatening generalized or systemic hypersensitivity reaction'. However, data indicate that the vast majority of food-triggered anaphylactic reactions are not life-threatening. Nonetheless, severe life-threatening reactions do occur and are unpredictable. We discuss the concepts surrounding perceptions of severe, life-threatening allergic reactions to food by different stakeholders, with particular reference to the inclusion of clinical severity as a factor in allergy and allergen risk management. We review the evidence regarding factors that might be used to identify those at most risk of severe allergic reactions to food, and the consequences of misinformation in this regard. For example, a significant proportion of food-allergic children also have asthma, yet almost none will experience a fatal food-allergic reaction; asthma is not, in itself, a strong predictor for fatal anaphylaxis. The relationship between dose of allergen exposure and symptom severity is unclear. While dose appears to be a risk factor in at least a subgroup of patients, studies report that individuals with prior anaphylaxis do not have a lower eliciting dose than those reporting previous mild reactions. It is therefore important to consider severity and sensitivity as separate factors, as a highly sensitive individual will not necessarily experience severe symptoms during an allergic reaction. We identify the knowledge gaps that need to be addressed to improve our ability to better identify those most at risk of severe food-induced allergic reactions.

The ins and outs of managing avoidance diets for food allergies

PURPOSE OF REVIEW

Food allergic reactions have become more prevalent and management of food allergies requires dietary avoidance of triggers that may place children at nutritional risk.

RECENT FINDINGS

Immunoglobulin E and non-immunoglobulin E-mediated food allergies lead to dietary avoidance. Although some children outgrow food allergies or become tolerant to cooked/baked versions of the allergen, many do not. Multiple food avoidance increases the risk for inadequate nutrient intake, including protein, calcium, vitamin D, and others. Multidisciplinary management of patients requires careful attention to growth, particularly height, and nutrition.

SUMMARY

Although attention to accurate diagnosis of food allergy is key, understanding nutritional risks of children with food allergies can lead to opportunities to address potential deficiencies resulting from food allergen avoidance.

Unintended allergens in precautionary labelled and unlabelled products pose significant risks to UK allergic consumers

BACKGROUND

Allergens in food may pose a risk to allergic consumers. While there is EU regulation for allergens present as an ingredient, this is not the case for unintended allergen presence (UAP). Food companies use precautionary allergen labels to inform allergic individuals of a potential risk from UAPs. This study investigates the risk of an allergic reaction within the milk-, wheat-, hazelnut- and peanut-allergic populations when ingesting UK foods across multiple product categories with and without precautionary allergen labelling.

METHODS

Allergen risk assessment using probabilistic techniques enables the estimation of the residual risk after the consumption of a product that unintentionally contains an allergen.

RESULTS

Within this selection of UK products, the majority that tested positive for an allergen contained a concentration of allergen predicted to cause a reaction in >1% of the allergic population. The concentrations of allergens measured were greater than the VITAL(®) 2.0 action levels and would trigger precautionary allergen labelling. This was found for products both with and without precautionary allergen labelling.

CONCLUSIONS

The results highlight the need for the food industry and regulators to adopt a transparent, risk-based approach for the communication of the risk associated with potential cross-contact that could occur in the processing facility or production chain.