Pathophysiological mechanisms of exercise-induced anaphylaxis: an EAACI position statement

Allergenic Biomarkers in the Molecular Diagnosis of IgE-Mediated Wheat Allergy

IgE-mediated wheat allergy can take on various forms, including childhood food allergy to wheat, wheat-dependent exercise-induced anaphylaxis in young adults, baker's respiratory allergy/asthma in workers exposed to wheat flour inhalation, and contact urticaria that is caused by hydrolyzed wheat proteins in some cosmetics, and that is sometimes associated with a food allergy. Singleplex and multiplex immunoassays detect specific IgE antibodies to wheat allergenic molecular biomarkers such as omega-5 gliadin Tri a 19, lipid transfer protein Tri a 14, and alpha-amylase inhibitors. The fluorescence enzyme immunoassay with capsulated cellulose polymer solid-phase coupled allergens is a commonly used singleplex assay. Multiplex methods include the ELISA-based macroarray immunoassay using nano-bead technology and a microarray immunoassay on polymer-coated slides. Another promising diagnostic tool is the basophil activation test performed with omega-5 gliadin and other wheat protein types. Detailed comprehension of the structural and immunological features of the numerous wheat allergens significant in clinical settings is imperative for advancing diagnostic biomarkers for IgE-mediated wheat allergies.

Routinely Used and Emerging Diagnostic and Immunotherapeutic Approaches for Wheat Allergy

Wheat, a component of the staple diet globally, is a common food allergen in children. The symptoms of wheat allergy (WA) range from skin rash to shortness of breath, significantly impairing quality of life. Following initial clinical suspicion, individuals may undergo routinely used allergy tests such as a wheat allergen-specific skin prick test (SPT), a blood test for specific immunoglobulin E (sIgE) levels, or oral food challenge. Conventional management of WA lies in wheat avoidance, yet accidental consumption may be inevitable owing to the ubiquity of wheat in various food products. This article aims to provide an overview of the immunologic pathway of WA, followed by its emerging diagnostic methods, namely alcohol-soluble SPT extracts, component-resolved diagnosis, and the basophil activation test (BAT). The mechanisms underlying wheat allergen-specific oral immunotherapy (OIT) as well as a summary of the efficacy, tolerability, and safety of related clinical trials will then be discussed.

Exercise-induced bronchoconstriction, allergy and sports in children

Exercise-induced bronchoconstriction (EIB) is characterized by the narrowing of airways during or after physical activity, leading to symptoms such as wheezing, coughing, and shortness of breath. Distinguishing between EIB and exercise-induced asthma (EIA) is essential, given their divergent therapeutic and prognostic considerations. EIB has been increasingly recognized as a significant concern in pediatric athletes. Moreover, studies indicate a noteworthy prevalence of EIB in children with atopic predispositions, unveiling a potential link between allergic sensitivities and exercise-induced respiratory symptoms, underpinned by an inflammatory reaction caused by mechanical, environmental, and genetic factors. Holistic management of EIB in children necessitates a correct diagnosis and a combination of pharmacological and non-pharmacological interventions. This review delves into the latest evidence concerning EIB in the pediatric population, exploring its associations with atopy and sports, and emphasizing the appropriate diagnostic and therapeutic approaches by highlighting various clinical scenarios.

Identification of RNAi hypoallergic bread wheat lines for wheat-dependent exercise-induced anaphylaxis patients

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is one of the most severe forms of wheat allergy. It occurs in patients when they exercise after ingesting wheat-containing foods. Nowadays, the only possible alternative for WDEIA patients is to avoid such foods. This study investigated the potential of six RNA of interference (RNAi) wheat lines with low-prolamin content as alternatives for WDEIA patients. For that purpose, a high performance-liquid chromatography (HPLC) analysis was performed to evaluate differences in gluten protein fractions among these lines. Next, western blots were conducted to measure the immunoglobulin E (IgE) reactivity to wheat proteins in sera from five WDEIA patients. Additionally, monoclonal antibodies (moAb) recognition sites and the IgE binding sites were searched in all peptides identified by LC-MS/MS after protein digestion. The results showed a 61.4%-81.2% reduction in the gliadin content of the RNAi lines, accompanied by an increase in their high-molecular weight (HMW) glutenin content compared to the wild type bread wheat line (WT). In all cases, the reduction in gliadin content correlated with a decrease in IgE reactivity observed in the sera of WDEIA patients, highlighting the E82 and H320 lines. These two RNAi lines exhibited a ≤90% reduction in IgE reactivity. This reduction could be attributed to an absence of IgE binding sites associated with α- and ω5-gliadins, which were present in the WT. Overall, these lines offer a potential alternative for foodstuff for individuals with WDEIA.

Food-Induced Anaphylaxis: Data From the European Anaphylaxis Registry

BACKGROUND

Food is one of the most common elicitors of anaphylaxis, with an increasing incidence over recent years.

OBJECTIVES

To characterize elicitor-specific phenotypes and identify factors enhancing the risk or severity of food-induced anaphylaxis (FIA).

METHODS

We analyzed data from the European Anaphylaxis Registry applying an age- and sex-matched analysis of associations (Cramer's V) for single food triggers and calculated odds ratios (ORs) for severe FIA.

RESULTS

We identified 3,427 cases of confirmed FIA showing an age-dependent elicitor ranking (for children: peanut, cow's milk, cashew, and hen's egg; and for adults: wheat flour, shellfish, hazelnut, and soy). The age- and sex-matched analysis revealed defined symptom patterns for wheat and cashew. Wheat-induced anaphylaxis was more frequently associated with cardiovascular symptoms (75.7%; Cramer's V = 0.28) and cashew-induced anaphylaxis with gastrointestinal symptoms (73.9%; Cramer's V = 0.20). Furthermore, concomitant atopic dermatitis was slightly associated with anaphylaxis to hen's egg (Cramer's V = 0.19) and exercise was strongly associated with anaphylaxis to wheat (Cramer's V = 0.56). Additional factors influencing the severity were alcohol intake in wheat anaphylaxis (OR = 3.23; CI, 1.31-8.83) and exercise in peanut anaphylaxis (OR = 1.78; CI, 1.09-2.95).

CONCLUSIONS

Our data show that FIA is age-dependent. In adults, the range of elicitors inducing FIA is broader. For some elicitors, the severity of FIA seems to be related to the elicitor. These data require confirmation in future studies considering a clear differentiation between augmentation and risk factors in FIA.

Food-Dependent Exercise-Induced Wheals/Angioedema, Anaphylaxis, or Both: A Systematic Review of Phenotypes

BACKGROUND

Food-dependent exercise-induced allergic reactions can manifest with wheals, angioedema, and anaphylaxis, alone or in combination.

OBJECTIVE

To systematically review the clinical manifestation, culprit foods and exercise, augmenting factors, comorbidities, and treatment options of each phenotype.

METHODS

Using predefined search terms, we assessed and analyzed the relevant literature until June 2021. Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations were applied to this systematic review.

RESULTS

A total of 231 studies with 722 patients were included. The most common phenotype was anaphylaxis with wheals, angioedema, or both, reported in 80% of patients. This was associated with a higher number of anaphylactic episodes, augmenting factors, and use of on-demand antihistamine compared with the least common phenotype, anaphylaxis without wheals or angioedema, reported in 4% of patients. Anaphylaxis with wheals/angioedema was also associated with distinct characteristics compared with stand-alone wheals, angioedema, or both, in 17% of patients. Patients with anaphylaxis were older at the time of disease onset, less often had a history of atopy, showed more positive results in response to food and exercise provocation tests, had a more restricted spectrum of culprit foods, and more often used on-demand epinephrine.

CONCLUSIONS

The three phenotypes of allergic reactions to food and exercise differ in clinical characteristics, triggers, and response to treatment. Knowledge of these differences may help with patient education and counseling as well as disease management.

The epidemiology of food allergy in adults

The prevalence and awareness of food allergy (FA) among US adults is arguably at a historical high, both with respect to primary immunoglobulin E-mediated food hypersensitivity and other food-triggered conditions that operate through a variety of immunologic mechanisms (eg, pollen-FA syndrome, alpha-gal syndrome, food protein-induced enterocolitis syndrome, eosinophilic esophagitis). Worryingly, not only are many adults retaining childhood-onset food allergies as they age into adulthood, it seems that many adults are experiencing adult-onset allergies to previously tolerated foods, with correspondingly adverse physical, and psychological health impacts. Consequently, this review aims to summarize what is currently known about the epidemiology and population-level burden of FA among adult populations in North America and around the globe. This article also provides insights into the natural history of these conditions and what we need to know as we look to the future to support effective care and prevent FA.

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.

A Narrative Mini Review on Current Status of Hypoallergenic Wheat Development for IgE-Mediated Wheat Allergy, Wheat-Dependent Exercise-Induced Anaphylaxis

Immunoglobulin E (IgE)-mediated food allergies to wheat that develop after school age typically shows a type of wheat-dependent exercise-induced anaphylaxis (WDEIA). At present, avoidance of wheat products or postprandial rest after ingesting wheat is recommended for patients with WDEIA, depending on the severity of the allergy symptoms. ω5-Gliadin has been identified as the major allergen in WDEIA. In addition, α/β-, γ-, and ω1,2-gliadins, high and low molecular weight-glutenins, and a few water-soluble wheat proteins have been identified as IgE-binding allergens in a small proportion of patients with IgE-mediated wheat allergies. A variety of approaches have been manufactured to develop hypoallergenic wheat products that can be consumed by patients with IgE-mediated wheat allergies. In order to analyze such approaches, and to contribute to the further improvement, this study outlined the current status of these hypoallergenic wheat productions, including wheat lines with a reduced allergenicity that are mostly constructed for the patients sensitized to ω5-gliadin, hypoallergenic wheat by enzymic degradation/ion exchanger deamidation, and hypoallergenic wheat by thioredoxin treatment. The wheat products obtained by these approaches significantly reduced the reactivity of Serum IgE in wheat-allergic patients. However, either these were not effective on some populations of the patients, or low-level IgE-reactivity to some allergens of the products was observed in the patients. These results highlight some of the difficulties faced in creating hypoallergenic wheat products or hypoallergenic wheat lines through either traditional breeding or biotechnology approaches in developing hypoallergenic wheat completely safe for all the patients allergic to wheat.

Diagnosis and management of allergy and respiratory disorders in sport: An EAACI task force position paper

Allergy and respiratory disorders are common in young athletic individuals. In the context of elite sport, it is essential to secure an accurate diagnosis in order to optimize health and performance. It is also important, however, to consider the potential impact or consequences of these disorders, in recreationally active individuals engaging in structured exercise and/or physical activity to maintain health and well-being across the lifespan. This EAACI Task Force was therefore established, to develop an up-to-date, research-informed position paper, detailing the optimal approach to the diagnosis and management of common exercise-related allergic and respiratory conditions. The recommendations are informed by a multidisciplinary panel of experts including allergists, pulmonologists, physiologists and sports physicians. The report is structured as a concise, practically focussed document, incorporating diagnostic and treatment algorithms, to provide a source of reference to aid clinical decision-making. Throughout, we signpost relevant learning resources to consolidate knowledge and understanding and conclude by highlighting future research priorities and unmet needs.

Food-Dependent Exercise-Induced Wheals, Angioedema, and Anaphylaxis: A Systematic Review

BACKGROUND

Food-dependent exercise-induced wheals, angioedema, and anaphylaxis remain insufficiently characterized.

OBJECTIVE

We systematically reviewed the literature on clinical manifestations, laboratory investigations, culprit foods, triggering exercise, comorbidities, and treatment outcomes.

METHODS

Using predefined search terms and Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) recommendations, we searched 3 electronic databases to identify relevant literature published before July 2021.

RESULTS

Of 722 patients (median age 25 years; 55.4% male) from 231 studies (43 cohort studies, 15 cases series, and 173 case reports), 79.6% and 3.7% had anaphylaxis with and without wheals and/or angioedema, respectively. The remaining 16.6% had wheals and/or angioedema without anaphylaxis. The duration from eating to exercising and from exercising to symptom onset ranged from 5 minutes to 6 hours (median 1 hour) and from 5 minutes to 5 hours (median 30 minutes), respectively, and virtually all patients exercised within 4 hours after eating and developed symptoms within 1 hour after exercising. Wheat was the most common culprit food. Running was the most common trigger exercise. Most patients were atopic, and 1 in 3 had a history of urticaria. Aspirin and wheat-based products were the most frequent augmenting factors. On-demand antihistamines, corticosteroids, and epinephrine were commonly used and reported to be effective. Patients who stopped eating culprit foods before exercise no longer developed food-dependent exercise-induced allergic reactions.

CONCLUSIONS

Food-dependent exercise-induced allergic reactions are heterogeneous in their clinical manifestations, triggers, and response to treatment. Patients benefit from avoidance of culprit foods before exercise, which highlights the need for allergological diagnostic workup and guidance.

The Effector Function of Allergens

Allergens are antigens that generate an IgE response (sensitization) in susceptible individuals. The allergenicity of an allergen can be thought of in terms of its ability to sensitize as well as its ability to cross-link IgE/IgE receptor complexes on mast cells and basophils leading to release of preformed and newly formed mediators (effector activity). The identity of the allergens responsible for sensitization may be different from those that elicit an allergic response. Effector activity is determined by (1) the amount of specific IgE (sIgE) and in some circumstances the ratio of sIgE to total IgE, (2) the number of high affinity receptors for IgE (FcεR1) on the cell surface, (3) the affinity of binding of sIgE for its epitope and, in a polyclonal response, the collective avidity, (4) the number and spatial relationships of IgE binding epitopes on the allergen and (5) the presence of IgG that can bind to allergen and either block binding of sIgE and/or activate low affinity IgG receptors that activate intracellular inhibitory pathways. This review will discuss these important immunologic and physical properties that contribute to the effector activity of allergens.

Anaphylaxis in children and adolescents: The Portuguese Anaphylaxis Registry

BACKGROUND

Anaphylaxis is increasing at pediatric age; however, its characterization is hampered by underdiagnosis and underreporting. The aim of this study was to identify the causes of anaphylaxis in children and adolescents in Portugal, thus contributing to a better knowledge of its etiology, clinical manifestations, and management.

METHODS

During a 10-year period, a nationwide notification system for anaphylaxis was implemented, with voluntary reporting by allergists. Data on 533 patients under 18 years of age with anaphylaxis were included.

RESULTS

Mean age was 8.5 ± 4.9 years, 61% were male; 45% had asthma. Mean age at the first anaphylaxis episode was 5.3 ± 4.7 years (ranging from 1 month to 17 years of age), 63% at pre-school age. Most reactions occurred at home (57%). Food-induced anaphylaxis was the leading cause (77%). The main culprit foods were cow's milk (32%), tree nuts (16%), shellfish (13%), egg (12%), fresh fruits (11%), fish (8%), and peanut (8%). Other causes included drugs (11%), insect sting (5%), cold-induced anaphylaxis (4%), exercise-induced anaphylaxis (2%), latex (1%), and idiopathic anaphylaxis (1%). Most patients (83%) were admitted to the emergency department; only 46% received adrenaline treatment. Recurrence of anaphylaxis occurred in 41% of the patients (3 or more episodes in 21%). An adrenaline autoinjector was used in 9% of the patients.

CONCLUSIONS

In the Portuguese pediatric population, food is the leading cause of anaphylaxis. Undertreatment with adrenaline and high recurrence of anaphylaxis highlight the need to improve both the diagnosis and the therapeutic management of this life-threatening entity.

The diagnosis and management of allergic reactions in patients sensitized to non-specific lipid transfer proteins

Sensitization to one or more non-specific lipid transfer proteins (nsLTPs), initially thought to exist mainly in southern Europe, is becoming accepted as a cause of allergic reactions to plant foods across Europe and beyond. The peach nsLTP allergen Pru p 3 is a dominant sensitizing allergen and peaches a common food trigger, although multiple foods can be involved. A frequent feature of reactions is the requirement for a cofactor (exercise, alcohol, non-steroidal anti-inflammatory drugs, Cannabis sativa) to be present for a food to elicit a reaction. The variability in the food and cofactor triggers makes it essential to include an allergy-focused diet and clinical history in the diagnostic workup. Testing on suspected food triggers should also establish whether sensitization to nsLTP is present, using purified or recombinant nsLTP allergens such as Pru p 3. The avoidance of known trigger foods and advice on cofactors is currently the main management for this condition. Studies on immunotherapy are promising, but it is unknown whether such treatments will be useful in populations where Pru p 3 is not the primary sensitizing allergen. Future research should focus on the mechanisms of cofactors, improving diagnostic accuracy and establishing the efficacy of immunotherapy.

Immune-Mediated Mechanisms in Cofactor-Dependent Food Allergy and Anaphylaxis: Effect of Cofactors in Basophils and Mast Cells

Cofactors may explain why in some cases food ingestion leads to anaphylaxis while in others elicits a milder reaction or tolerance. With cofactors, reactions become more severe and/or have a lower allergen threshold. Cofactors are present in up to 58% of food anaphylaxis (FAn). Exercise, NSAIDs, and alcohol are the most frequently described, although the underlying mechanisms are poorly known. Several hypotheses have suggested the influence of these cofactors on basophils and mast cells (MCs). Exercise has been suggested to enhance MC activation by increasing plasma osmolarity, redistributing blood flow, and activating adenosine and eicosanoid metabolism. NSAIDs’ cofactor effect has been related with cyclooxygenase inhibition and therefore, prostaglandin E₂ (PGE₂) production. Indeed, overexpression of adenosine receptor 3 (A₃) gene has been described in NSAID-dependent FAn; A₃ activation potentiates FcϵRI-induced MC degranulation. Finally, alcohol has been related with an increase of histamine levels by inhibition of diamino oxidase (DAO) and also with and increase of extracellular adenosine by inhibition of its uptake. However, most of these mechanisms have limited evidence, and further studies are urgently needed. In conclusion, the study of the immune-related mechanisms involved in food allergic reactions enhanced by cofactors is of the utmost interest. This knowledge will help to design both tailored treatments and prophylactic strategies that, nowadays, are non-existent.

Design, Assessment, and Validation of a Questionnaire to Estimate Food-Dependent Exercise-Induced Anaphylaxis Prevalence in Latin American Population

There are no epidemiological data about food-dependent exercise-induced anaphylaxis (FDEIA) in Latin America. Our aim was to design, assess, and validate a questionnaire to identify potential FDEIA cases and/or estimate its prevalence by self-report. Questions were included in the instrument to address the main symptoms of FDEIA, type/intensity of physical activity, and anaphylaxis. The instrument’s clarity, comprehension and repeatability were evaluated. These evaluations were carried out by Hispanic people (Argentinians/Colombians/Mexicans/Peruvians), including nine individuals with medical diagnosis of FDEIA, and Brazilians. The Flesch–Kincaid score was calculated using the INFLESZ software. The instrument was translated from Spanish to Brazilian Portuguese following the translation back-translation procedure. The participants rated the two versions of the questionnaire as clear and comprehensible (three-point ordinal scale) and very easy to understand [0.33; average (scale 0–10)]. For these evaluations, the Kendall’s W coefficient showed strong agreement among raters (W = 0.80; average). The Flesch–Kincaid score was 63.5 in average (documents considered as readable). The Cohen’s Kappa coefficient showed almost perfect agreement in repeatability (0.88; average). The validation process of two versions of an instrument, used to identify potential FDEIA cases, was successfully carried out and it was found applicable to Latin American countries for generating epidemiological data.

Risk Factors and Characteristics of Biphasic Anaphylaxis

BACKGROUND

Anaphylaxis is an immediate hypersensitivity reaction. However, a biphasic course with the second onset of symptoms can occur hours after the initial phase. Little is known about the causes of biphasic anaphylaxis making the identification of patients at risk difficult.

OBJECTIVE

To identify factors predisposing for biphasic anaphylaxis for the better understanding of these reactions.

METHODS

Data from the Anaphylaxis Registry (from 11 countries) including 8736 patients with monophasic and 435 biphasic anaphylaxis were analyzed.

RESULTS

The rate of biphasic reactions in this large cohort was 4.7%. The identified risk factors were reaction severity (grade III/IV vs grade II: odds ratio [OR] = 1.34; 95% confidence interval [CI]: 1.1-1.62); multiorgan involvement; skin, gastrointestinal, severe respiratory, and cardiac symptoms; anaphylaxis caused by peanut/tree nut (OR = 1.78; 95% CI: 1.38-2.23) or an unknown elicitor (OR = 1.96; 95% CI: 1.41-2.72); exercise as a cofactor (OR = 1.44; 95% CI: 1.17-1.78); chronic urticaria as a comorbidity (OR = 2.12; 95% CI: 1.19-3.78); a prolonged interval between the contact with the elicitor and start of primary symptoms (OR for >30 vs <30 min: 1.38; 95% CI: 1.08-1.76); and antihistamine treatment (OR = 1.52; 95% CI: 1.14-2.02).

CONCLUSION

A biphasic course of anaphylaxis occurs more frequently in severely affected patients with multiorgan involvement. However, we identified multiple additional predictors, suggesting that the pathogenesis of biphasic reactions is more complex than being a rebound of a severe primary reaction.

Food-dependent exercise-induced anaphylaxis

PURPOSE OF REVIEW

The following article provides an overview of food-dependent exercise-induced anaphylaxis (FD-EIAn). The review focuses on the epidemiology, pathophysiology, and clinical findings of FD-EIAn and details current practice in terms of the investigation, management, and treatment options available.

RECENT FINDINGS

The management of FD-EIAn has not changed significantly over the last few years and still requires careful investigation by an experienced clinician to ensure that the correct diagnosis is made and appropriate treatment is given. Although new therapies such as synthetic prostaglandin E1 analogs and IgE monoclonal antibodies have been trialed as treatment options for FD-EIAn, the mainstay of treatment remains the graded reintroduction to exercise in a supervised setting.

SUMMARY

FD-EIAn is a rare but serious condition that can have a significant impact on patients' lives. This review aims to discuss new relevant research into this field to help guide clinicians in managing this condition.

Incidence of Adverse Reactions to Parenteral Thiamine in the Treatment of Wernicke's Encephalopathy, and Recommendations

AIM

To offer an estimate of the incidence of anaphylactic reactions to parenteral products containing thiamine used in the treatment of Wernicke's encephalopathy (WE) and make recommendations.

METHOD

Review of previously released data on some older products and parenteral thiamine use in some other countries; analysis of sales and adverse incident data on anaphylaxis for a contemporary parenteral product used in the UK, Pabrinex.

RESULTS

It was difficult to estimate the incidence of related anaphylactic reactions to Pabrinex in the UK because the number of doses given is unknown. Sales data are only an approximation to doses given because for products with a limited shelf life not all product sold is administered. However, available data indicate that there have been 10 anaphylactic reactions to Pabrinex from between 5,431,235-6,651,947 patient-days (14,880-16,080 years) of treatment.

CONCLUSION

It is reasonable to assume that the risk of anaphylaxis is low, and lower than for many other drugs. The risk-benefit ratio for administration is favourable given the potential severity of brain damage in Wernicke-Korsakoff (WK) syndrome. There is a need for international agreement on the reporting of anaphylaxis and on the optimum thiamine therapy for the treatment of WK syndrome. We make recommendations on how this might be achieved.

Exercise plasma metabolomics and xenometabolomics in obese, sedentary, insulin-resistant women: impact of a fitness and weight loss intervention

Insulin resistance has wide-ranging effects on metabolism, but there are knowledge gaps regarding the tissue origins of systemic metabolite patterns and how patterns are altered by fitness and metabolic health. To address these questions, plasma metabolite patterns were determined every 5 min during exercise (30 min, ∼45% of V̇o_2peak, ∼63 W) and recovery in overnight-fasted sedentary, obese, insulin-resistant women under controlled conditions of diet and physical activity. We hypothesized that improved fitness and insulin sensitivity following a ∼14-wk training and weight loss intervention would lead to fixed workload plasma metabolomics signatures reflective of metabolic health and muscle metabolism. Pattern analysis over the first 15 min of exercise, regardless of pre- versus postintervention status, highlighted anticipated increases in fatty acid tissue uptake and oxidation (e.g., reduced long-chain fatty acids), diminution of nonoxidative fates of glucose [e.g., lowered sorbitol-pathway metabolites and glycerol-3-galactoside (possible glycerolipid synthesis metabolite)], and enhanced tissue amino acid use (e.g., drops in amino acids; modest increase in urea). A novel observation was that exercise significantly increased several xenometabolites ("non-self" molecules, from microbes or foods), including benzoic acid-salicylic acid-salicylaldehyde, hexadecanol-octadecanol-dodecanol, and chlorogenic acid. In addition, many nonannotated metabolites changed with exercise. Although exercise itself strongly impacted the global metabolome, there were surprisingly few intervention-associated differences despite marked improvements in insulin sensitivity, fitness, and adiposity. These results and previously reported plasma acylcarnitine profiles support the principle that most metabolic changes during submaximal aerobic exercise are closely tethered to absolute ATP turnover rate (workload), regardless of fitness or metabolic health status.

Exercise Lowers Threshold and Increases Severity, but Wheat-Dependent, Exercise-Induced Anaphylaxis Can Be Elicited at Rest

BACKGROUND

Wheat-dependent, exercise-induced anaphylaxis (WDEIA) is a severe form of allergy in which exercise is being considered as mandatory. The diagnosis is often complex and the clinical reproducibility low.

OBJECTIVE

The aims of this study were to establish a standardized challenge method for the diagnosis of WDEIA and to investigate whether exercise is an essential trigger factor or alternatively an augmentation factor able to lower threshold and increase severity.

METHODS

We investigated 71 patients (age, 18.6-73.7 years) with a case history of WDEIA. Skin prick test (SPT) and measurement of specific IgE (sIgE) were followed by an oral food challenge with gluten at rest and in combination with treadmill exercise.

RESULTS

A clinical reaction was elicited in 47 of 71 (66%), and in 26 of these (37%) the reaction could be elicited at rest. The median dose required at rest was 48 g (8-80 g) and in combination with exercise 24 g (4-80 g). Severity was significantly higher with exercise (2.3) than at rest (1.1) using Sampson severity score. In the challenge, SPT was positive to wheat in 93.6% (44 of 47) and to gluten in 95.7% (45 of 47). sIgE to wheat, gliadin, and omega-5 gliadin was present in 78.7% (37 of 47), 76.5% (36 of 47), and 91.4% (43 of 47) of the patients. Receiver operating characteristic-curve analysis for sIgE to omega-5 gliadin, a component of the gluten fraction and the major allergen in WDEIA, showed best sensitivity (91%) and specificity (92%) when gluten was combined with exercise.

CONCLUSIONS

A challenge test with gluten at rest and combined exercise is a safe confirmatory test for WDEIA. A reaction can be elicited at rest (without exercise), but exercise is able to lower the threshold and increase the severity.

Diagnosis and prevention of food-dependent exercise-induced anaphylaxis

Introduction: Food-dependent, exercise-induced anaphylaxis (FDEIA) is a rare type of anaphylaxis with a growing incidence. Although the precise mechanism by which the patient reacts only in a combination of a culprit food and cofactors are not currently understood, many advances in diagnosis and management have been made since their first description. Areas covered: A literature search in PubMed was performed to review the diagnosis and management of FDEIA. Clinicians should have a high level of suspicion for identification of the culprit foods and the cofactors involved. Component-resolved diagnosis and more accurate provocation tests have revolutionized the diagnosis accuracy. Management is not easy and involves educating the patient to evict the combination of exposure to the culprit foods and the cofactors that elicit anaphylaxis, and how to act and treat if a reaction occurs. Expert opinion: FDEIA is currently misdiagnosed and the authors believe that there are many FDEIA patients labelled as idiopathic anaphylaxis with unnecessary evictions and with a poor quality of life because of the fear of an imminent reaction. Due to recent advances in diagnostic tools and the use of monoclonal antibodies for prophylaxis in persistent cases, FDEIA can have a better prognosis improving the quality of life of the patients and their families.

Clinical and serological follow-up of patients with WDEIA

The clinical threshold in wheat-dependent, exercise-induced anaphylaxis seems to be lowered in patients on wheat free diet, whereas the opposite is seen in patients on regular wheat intake. Therefore, a recommendation of wheat consumption, if considered safe to the patient based on case-history and challenge results, could be advised.

Cofactors of wheat-dependent exercise-induced anaphylaxis do not increase highly individual gliadin absorption in healthy volunteers

Background

In wheat-dependent exercise-induced anaphylaxis (WDEIA), cofactors such as exercise, acetylsalicylic acid (ASA), alcohol or unfavorable climatic conditions are required to elicit a reaction to wheat products. The mechanism of action of these cofactors is unknown, but an increase of gliadin absorption has been speculated. Our objectives were to study gliadin absorption with and without cofactors and to correlate plasma gliadin levels with factors influencing protein absorption in healthy volunteers.

Methods

Twelve healthy probands (six males, six females; aged 20–56 years) ingested 32 g of gluten without any cofactor or in combination with cofactors aerobic and anaerobic exercise, ASA, alcohol and pantoprazole. Gliadin serum levels were measured up to 120 min afterwards and the intestinal barrier function protein zonulin in stool was collected before and after the procedure; both were measured by ELISA. Stool microbiota profile was obtained by 16S gene sequencing.

Results

Within 15 min after gluten intake, gliadin concentrations in blood serum increased from baseline in all subjects reaching highly variable peak levels after 15–90 min. Addition of cofactors did not lead to substantially higher gliadin levels, although variability of levels was higher with differences between individuals (p < 0.001) and increased levels at later time points. Zonulin levels in stool were associated neither with addition of cofactors nor with peak gliadin concentrations. There were no differences in gut microbiota between the different interventions, although the composition of microbiota (p < 0.001) and the redundancy discriminant analysis (p < 0.007) differed in probands with low versus high stool zonulin levels.

Conclusion

The adsorption of gliadin in the gut in healthy volunteers is less dependent on cofactors than has been hypothesized. Patients with WDEIA may have a predisposition needed for the additional effect of cofactors, e.g., hyperresponsive or damaged intestinal epithelium. Alternatively, other mechanisms, such as cofactor-induced blood flow redistribution, increased activity of tissue transglutaminase, or increases in plasma osmolality and acidosis inducing basophil and mast cell histamine release may play the major role in WDEIA.

Exercise-induced anaphylaxis with an Ayurvedic drug as cofactor: A case report

BACKGROUND

The practice of Indian Ayurvedic medicine is spreading in Western countries and Shilajit is one of the most used drugs, for its antioxidant activities and immunomodulatory effects. Albeit Shilajit has showed a high degree of safety, it can act as cofactor of anaphylaxis, especially in condition at high risk, such as mast cell activation syndrome (MCAS). We reported this case to sensitize practitioners to investigate to the use of complementary and alternative medicine, in case of exercise-induced anaphylaxis (EIAn).

CASE SUMMARY

A 43-year-old woman, working as a dance teacher, developed urticaria after ingestion of rice, tuna and Shilajit, which did not respond to intramuscular corticosteroids. Subsequently, she developed dyspnoea and hypotension with loss of consciousness that arose 1 h after sexual activity. The patient did not refer personal history of atopy. Specific IgE for main food allergens resulted negative, with total IgE levels of 14 IU/L. Oral provocation test with Shilajit was not perfomed because the patient refused, but we performed prick-by-prick and patch test that resulted negative. Serum tryptase at the time of anaphylaxis was 20.6 μg/L that fell down to of 10.6 μg/L after therapy, but has remained at the high value after two days and during the follow-up. We performed an analysis of the c-KIT gene in peripheral blood, which was negative. We felt the diagnosis consistent with EIAn in a patient with a possible MCAS.

CONCLUSION

In Western countries the use of drugs from Ayurvedic medicine is more common than in the past. These substances can be cofactors of anaphylaxis in patients with risk factors.

Exercise-induced anaphylaxis with an Ayurvedic drug as cofactor: A case report

BACKGROUND

The practice of Indian Ayurvedic medicine is spreading in Western countries and Shilajit is one of the most used drugs, for its antioxidant activities and immunomodulatory effects. Albeit Shilajit has showed a high degree of safety, it can act as cofactor of anaphylaxis, especially in condition at high risk, such as mast cell activation syndrome (MCAS). We reported this case to sensitize practitioners to investigate to the use of complementary and alternative medicine, in case of exercise-induced anaphylaxis (EIAn).

CASE SUMMARY

A 43-year-old woman, working as a dance teacher, developed urticaria after ingestion of rice, tuna and Shilajit, which did not respond to intramuscular corticosteroids. Subsequently, she developed dyspnoea and hypotension with loss of consciousness that arose 1 h after sexual activity. The patient did not refer personal history of atopy. Specific IgE for main food allergens resulted negative, with total IgE levels of 14 IU/L. Oral provocation test with Shilajit was not perfomed because the patient refused, but we performed prick-by-prick and patch test that resulted negative. Serum tryptase at the time of anaphylaxis was 20.6 μg/L that fell down to of 10.6 μg/L after therapy, but has remained at the high value after two days and during the follow-up. We performed an analysis of the c-KIT gene in peripheral blood, which was negative. We felt the diagnosis consistent with EIAn in a patient with a possible MCAS.

CONCLUSION

In Western countries the use of drugs from Ayurvedic medicine is more common than in the past. These substances can be cofactors of anaphylaxis in patients with risk factors.

Exercise-Induced Anaphylaxis: Literature Review and Recent Updates

PURPOSE OF REVIEW

This paper will review the pathophysiology, diagnosis, and treatment of exercise-induced anaphylaxis and food-dependent, exercise-induced anaphylaxis with an emphasis on novel studies published in the past several years.

RECENT FINDINGS

Exercise-induced anaphylaxis (EIAn) is a clinical syndrome characterized by anaphylaxis during or shortly after physical exertion. The syndrome is broadly grouped into two categories: exercise-induced anaphylaxis and food-dependent, exercise-induced anaphylaxis (FDEIAn). Recent literature indicates that FDEIAn is a primary IgE-mediated food allergy which is augmented by several cofactors. Cofactors such as exercise, NSAIDs, and alcohol increase intestinal permeability and allow increased antigen uptake, thereby causing symptoms. The pathophysiology of EIAn is still under investigation. EIAn and FDEIAn are rare clinical syndromes characterized by symptoms during or shortly after exercise. Despite recent advances in the understanding of EIAn and FDEIAn, the pathophysiology of both conditions is not fully understood.

Potential cofactors in accidental food allergic reactions are frequently present but may not influence severity and occurrence

BACKGROUND

Cofactors, such as physical exercise and alcohol intake, might be associated with the severity or occurrence of food allergic reactions.

OBJECTIVE

To gain insight into the frequency of presence of potential cofactors in accidental food allergic reactions in adults and to what extent these factors influence the severity and occurrence of allergic reactions.

METHODS

A prospective cohort study was conducted, with a 1-year follow-up in adult patients with a physician-diagnosed food allergy. Patients were required to fill in a questionnaire after every accidental allergic reactions to food over a 1-year period. The primary outcome measure was the frequency that potential cofactors were present in these allergic reactions.

RESULTS

A total of 157 patients were included, of which 46% reported a total of 153 reactions during a 1-year follow-up period. In 74% of the reactions, ≥1 potential cofactor was reported to be present: tiredness (38%), alcohol intake (16%), stress (14%), symptoms of pollinosis (16%), symptoms of asthma (9%), sickness/flu (3%), physical exercise (3%) and use of analgesics (2%). More than one potential cofactor was reported in almost half of all reactions (47%). There was no significant difference in the presence of these factors between mild, moderate and severe reactions (P = 0.522). In the total study population, 9% of the patients used medication that might act as cofactor (antacids, angiotensin receptor blockers [ARBs], beta blockers and angiotensin-converting enzyme inhibitors [ACEIs]) on a daily basis, which however did not influence the occurrence of reactions. Furthermore, 38% daily used allergy-suppressing medication.

CONCLUSIONS

Although factors suggested to be cofactors were frequently present during accidental food allergic reactions, we found no evidence for an association between the potential cofactors examined and reaction severity, in a population where most reactions were of mild to moderate severity.

Cow's milk oral immunotherapy in real life: 8-year long-term follow-up study

Background

Oral immunotherapy (OIT) has been recognized as a promising treatment for severe and long-lasting cow's milk (CM) allergy. Once maintenance has been achieved, patients should maintain daily intake of CM to ensure desensitization. Clinical experience concerning long-term follow-up is scarce.

Objective

The authors aimed to assess long-term efficacy and safety of a maintenance phase of OIT in real life.

Methods

Prospective study of all children and adolescents, who underwent CM-OIT and were subsequently followed at our allergy center on maintenance dose (200 mL daily) for at least 36 months after reaching the maintenance phase (from 2009 to 2016).

Results

Forty-two patients were enrolled: 60% male, 36% with history of anaphylaxis and 57% with asthma. The median time of follow-up was 69 months (range, 39–105 months) and the median age at the last clinical evaluation was 13 years (range, 6–23 years). Regarding adherence to the protocol: 92% are on free diet (at least 200 mL of CM daily; 7-g protein); 14% had transient interruptions and 7% definitely withdrawn with loss of tolerance. During maintenance, 45% developed mild to severe allergic reactions, and 7% had more than 3 episodes. A positive correlation between the occurrence of allergic reactions and history of anaphylaxis (p < 0.001) was found. The coexistence of asthma was risk factor for the occurrence of allergic reactions during maintenance.

Conclusion

This real-life study supports long-term efficacy and safety of CM-OIT. Despite daily intake, 41% had symptoms at some moment during the complete follow-up period; a total of 33 symptomatic days in patients with mean follow-up time of 67.5 months. Clinical tolerance depends on daily intake. The protective effect reached can be lost after CM withdrawal. History of anaphylaxis was a risk factor for the occurrence of allergic reactions during the maintenance phase.

Wheat-Dependent Cofactor-Augmented Anaphylaxis: A Prospective Study of Exercise, Aspirin, and Alcohol Efficacy as Cofactors

BACKGROUND

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a severe and potentially life-threatening allergy caused by wheat ingestion and most commonly in combination with exercise.

OBJECTIVE

To investigate the role and impact of different cofactors (exercise, aspirin, and alcohol) in patients with WDEIA.

METHODS

We studied 25 adult patients with WDEIA. Diagnostic workup included specific IgE to omega-5 gliadin and skin prick test with wheat flour and gluten. Titrated oral challenge was performed with gluten at rest, combined with treadmill exercise, aspirin, alcohol, or a combination of exercise and aspirin.

RESULTS

A positive challenge to gluten was found at rest (without cofactors) in 48% (12 of 25), with exercise in 92% (23 of 25), with aspirin in 84% (21 of 25), with alcohol in 56% (9 of 19), and with a combination of exercise and aspirin in 82% (18 of 22) of the patients. With exercise as a cofactor, the median threshold was 24 g (range, 4.8-80 g), with aspirin 8 g (range, 2.4-80 g), and with alcohol 28 g (range, 0-45 g). The combination of 2 cofactors (exercise and aspirin) resulted in a median threshold of 4.3 g (range, 1.1-48 g). The threshold for the clinical reaction was lowered by 63%, 83%, 36%, and 87%, respectively, compared with at rest. The mean severity grade (scale 0-5) according to the Sampson severity score at rest was 0.8 (range, 0-2), and when combined with exercise 2.1 (range, 0-5), with aspirin 1.9 (range, 0-5), with alcohol 0.8 (range, 0-2), and with the combination of exercise and aspirin 1.5 (range, 0-2).

CONCLUSION

Our results demonstrate that exercise and aspirin augment clinical reactions in WDEIA by lowering the threshold and increase the severity of the allergic reaction, whereas alcohol gives ambiguous results. Furthermore, a combination of 2 cofactors (exercise and aspirin) increases the risk of reactions.

Exercise-Induced Bronchoconstriction: Background, Prevalence, and Sport Considerations

The transient airway narrowing that occurs as a result of exercise is defined as exercise-induced bronchoconstriction (EIB). The prevalence of EIB has been reported to be up to 90% in asthmatic patients, reflecting the level of disease control. However, EIB may develop even in subjects without clinical asthma, particularly in children, athletes, patients with atopy or rhinitis, and following respiratory infections. The intensity, duration, and type of training have been associated with the occurrence of EIB. In athletes, EIB seems to be only partly reversible, and exercise seems to be a causative factor of airway inflammation and symptoms.

How to manage anaphylaxis in primary care

Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction characterized by rapidly developing airway and/or circulation problems. It presents with very different combinations of symptoms and apparently mild signs and can progress to fatal anaphylactic shock unpredictably. The difficulty in recognizing anaphylaxis is due, in part, to the variability of diagnostic criteria, which in turn leads to a delay in administration of appropriate treatment, thus increasing the risk of death. The use of validated clinical criteria can facilitate the diagnosis of anaphylaxis. Intramuscular epinephrine (adrenaline) is the medication of choice for the emergency treatment of anaphylaxis. Administration of corticosteroids and H1-antihistamines should not delay the administration of epinephrine, and the management of a patient with anaphylaxis should not end with the acute episode. Long-term management of anaphylaxis should include avoidance of triggers, following confirmation by an allergology study. Etiologic factors suspected in the emergency department often differ from the real causes of anaphylaxis. Evaluation of patients with a history of anaphylaxis should also include an assessment of personal data, such as age and comorbidities, which may increase the risk of severe reactions. Special attention should also be paid to co-factors, as these may easily confound the cause of the anaphylaxis. Patients experiencing anaphylaxis should administer epinephrine as soon as possible. Education (including the use of Internet and social media), written personalized emergency action plans, and self-injectable epinephrine have proven useful for the treatment of further anaphylaxis episodes.

Long-term omalizumab use in the treatment of exercise-induced anaphylaxis

Reported is a case of a 39-year-old male who was diagnosed with exercise-induced anaphylaxis (EIA). He was initially treated prophylactically with fexofenadine, montelukast, and ranitidine. He also used an epinephrine autoinjector as needed. He was refractory to these medications and continued to have episodes of EIA. He was then started on a trial of omalizumab, an immunoglobulin E monoclonal antibody, and had resolution of the EIA episodes. After discontinuation of the omalizumab, the EIA episodes returned. He was restarted on omalizumab and since that time, has had 5 years free of EIA episodes and can now exercise without any symptoms. To our knowledge, this is only the third case in the literature of successful treatment of EIA by using omalizumab. This case was unique because it provided successful long-term use of omalizumab for EIA. Further studies are recommended for the use of omalizumab in the treatment of EIA.

[Food-induced anaphylaxis - data from the anaphylaxis registry]

Anaphylactic reactions due to food occur in the context of food allergy and, together with venom and drugs, are the most frequent elicitors of severe allergic reactions. In small children the most frequent elicitors of severe allergic reactions according to data from the anaphylaxis registry are hen's egg and milk, whereas in school children peanut and hazelnut are frequent elicitors of allergic reactions. Other frequent elicitors of anaphylactic reactions in childhood are wheat and soy. In adults the most frequent elicitors of severe allergic reactions due to food, based on data from the anaphylaxis registry, are wheat, soy, celery, shellfish and hazelnut. Rare elicitors of food-induced anaphylaxis in German-speaking countries are mustard and cabbage. However, the panel of rare elicitors of food-induced anaphylaxis show regional differences. As of March 2015, 17 cases of fatal anaphylaxis were registered and among these seven were food-induced. Co-factors can either trigger the elicitation of a severe allergic reaction or affect its severity. Among such co-factors are physical activity, the intake of certain drugs, and psychological stress. The data on the role of cofactors is sparse. The management of food-induced anaphylaxis includes acute management according to current guidelines, but also long-term management, which should include educational measures regarding treatment but also information about the food allergen in daily life.

Epinephrine for First-aid Management of Anaphylaxis

Anaphylaxis is a severe, generalized allergic or hypersensitivity reaction that is rapid in onset and may cause death. Epinephrine (adrenaline) can be life-saving when administered as rapidly as possible once anaphylaxis is recognized. This clinical report from the American Academy of Pediatrics is an update of the 2007 clinical report on this topic. It provides information to help clinicians identify patients at risk of anaphylaxis and new information about epinephrine and epinephrine autoinjectors (EAs). The report also highlights the importance of patient and family education about the recognition and management of anaphylaxis in the community. Key points emphasized include the following: (1) validated clinical criteria are available to facilitate prompt diagnosis of anaphylaxis; (2) prompt intramuscular epinephrine injection in the mid-outer thigh reduces hospitalizations, morbidity, and mortality; (3) prescribing EAs facilitates timely epinephrine injection in community settings for patients with a history of anaphylaxis and, if specific circumstances warrant, for some high-risk patients who have not previously experienced anaphylaxis; (4) prescribing epinephrine for infants and young children weighing <15 kg, especially those who weigh 7.5 kg and under, currently presents a dilemma, because the lowest dose available in EAs, 0.15 mg, is a high dose for many infants and some young children; (5) effective management of anaphylaxis in the community requires a comprehensive approach involving children, families, preschools, schools, camps, and sports organizations; and (6) prevention of anaphylaxis recurrences involves confirmation of the trigger, discussion of specific allergen avoidance, allergen immunotherapy (eg, with stinging insect venom, if relevant), and a written, personalized anaphylaxis emergency action plan; and (7) the management of anaphylaxis also involves education of children and supervising adults about anaphylaxis recognition and first-aid treatment.

Cross-reactive LTP sensitization in food-dependent exercise-induced urticaria/anaphylaxis: a pilot study of a component-resolved and in vitro depletion approach

Background

Challenge tests for food-dependent exercise-induced anaphylaxis (FDEIA) carry some risk and have a high rate of false negatives. Our aim was to explore the usefulness of an in vitro immunodepletion assay and an allergen microarray test in the identification of IgE-mediated cross-reactive food allergens in patients with suspected FDEIA or food-dependent exercise-induced urticaria and panallergen sensitization.

Methods

Three patients with a history of food dependent exercise induced urticaria/anaphylaxis and food panallergen sensitization in whom a food-exercise challenge was not feasible were selected: a 25-year-old man with cholinergic urticaria who experienced generalized urticaria and angioedema during a soccer match after drinking a peach-based soft drink; a 19-year-old woman with allergic rhinitis and controlled asthma who experienced anaphylactic shock while playing soccer, having eaten walnuts in the previous 90 min; and a 57-year-old man with baker’s asthma who experienced four episodes of anaphylaxis during exercise after ingesting wheat-containing food. All individuals underwent a diagnostic work-up with skin prick tests, specific IgE (sIgE) and ImmunoCAP ISAC test. For the in vitro immunodepletion procedure, patients’ serum was pre-incubated with the suspected native allergen (peach, walnut, or wheat) in solid phase (ImmunoCAP). The eluted serum, containing unbound IgE, was collected and samples were re-tested using Immunocap ISAC 112 and compared with baseline results.

Results

All individuals were sensitized to lipid transfer proteins. The first patient was sensitized to Pru p 3, Cor a 8, Jug r 3, and Ara h 9; after pre-incubation with peach there was 100% depletion of sIgE to all components. The second patient was sensitized to Pru p 3, Cor a 8, Jug r 3, and Ara h 9; immunodepletion with walnut depleted sIgE to Ara h 9 by 67%, Pru p 3 and Pla a 3 (60%), Art v 3 (75%), Jug r 3 (88%), and Cor a 8 (100%). The third patient was sensitized to Pru p 3, Jug r 3, Ara h 9, and Tri a 14; immunodepletion with wheat depleted Tri a 14 only (100%).

Conclusions

In vitro immunodepletion might be a useful diagnostic tool in food dependent exercise induced urticaria/anaphylaxis with panallergen sensitization, particularly for identifying the culprit allergen and guiding dietary elimination recommendations.

Diagnosis of exercise-induced anaphylaxis: current insights

Exercise-induced anaphylaxis (EIAn) is defined as the occurrence of anaphylactic symptoms (skin, respiratory, gastrointestinal, and cardiovascular symptoms) after physical activity. In about a third of cases, cofactors, such as food intake, temperature (warm or cold), and drugs (especially nonsteroidal anti-inflammatory drugs) can be identified. When the associated cofactor is food ingestion, the correct diagnosis is food-dependent EIAn (FDEIAn). The literature describes numerous reports of FDEIAn after intake of very different foods, from vegetables and nuts to meats and seafood. One of the best-characterized types of FDEIAn is that due to ω5-gliadin of wheat, though cases of FDEIAn after wheat ingestion by sensitization to wheat lipid transfer protien (LTP) are described. Some pathophysiological mechanisms underlying EIAn have been hypothesized, such as increase/alteration in gastrointestinal permeability, alteration of tissue transglutaminase promoting IgE cross-linking, enhanced expression of cytokines, redistribution of blood during physical exercise leading to altered mast-cell degranulation, and also changes in the acid–base balance. Nevertheless, until now, none of these hypotheses has been validated. The diagnosis of EIAn and FDEIAn is achieved by means of a challenge, with physical exercise alone for EIAn, and with the assumption of the suspected food followed by physical exercise for FDEIAn; in cases of doubtful results, a double-blind placebo-controlled combined food–exercise challenge should be performed. The prevention of this particular kind of anaphylaxis is the avoidance of the specific trigger, ie, physical exercise for EIAn, the assumption of the culprit food before exercise for FDEIAn, and in general the avoidance of the recognized cofactors. Patients must be supplied with an epinephrine autoinjector, as epinephrine has been clearly recognized as the first-line intervention for anaphylaxis.

Cofactors in allergic reactions to food: physical exercise and alcohol are the most important

Introduction

Involvement of cofactors, like physical exercise, alcohol consumption and use of several types of medication, are associated with more severe food allergic symptoms. However, there is limited evidence on how often cofactors play a role in food allergic reactions. The study aimed to get more insight into the frequency of exposure to cofactors and how often cofactors are associated with more severe symptoms in food allergic patients.

Methods

A questionnaire was completed by patients visiting the Allergology outpatient clinic. Patients with food allergy were included. Outcome measures were the frequency of medication use of medication groups that might act as cofactor and the frequency that physical exercise, alcohol consumption and use of analgesics are associated with more severe food allergic symptoms.

Results

Four hundred ninety‐six patients were included in the study. The frequency with which patients used one or more types of medication that might act as cofactors was 7.7%: antacids/acid neutralizing medication (5%), NSAIDs (2%), beta blockers (0.6%), angiotensin‐converting enzyme inhibitors (0.6%), and angiotensin receptor blockers (0.2%). Of all patients, 13% reported more severe symptoms to food after involvement of one or more of the cofactors: physical exercise (10%), alcohol consumption (5%), and use of analgesics (0.6%). Sixty‐five percent did not know if these cofactors caused more severe symptoms; 22% reported that these cofactors had no effect.

Conclusions

Only a small percentage of patients (7.7%) used medication that might aggravate food allergic reactions. Physical exercise and alcohol consumption were the most frequently reported cofactors, but occurring still in only 10% or less.

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.

Dysfunctional breathing and reaching one's physiological limit as causes of exercise-induced dyspnoea

Key points

This review provides an overview of the spectrum of conditions that can present as exercise-­induced breathlessness experienced by young subjects participating in sport and aims to promote understanding of the need for accurate assessment of an individual’s symptoms. We will highlight the high incidence of nonasthmatic causes, which simply require reassurance or simple interventions from respiratory physiotherapists or speech pathologists.

Breathlessness: accurate assessment and diagnosis is essential in order to provide correct advice and assistancehttp://ow.ly/4nrW8z

EAACI Molecular Allergology User's Guide

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.

2015 update of the evidence base: World Allergy Organization anaphylaxis guidelines

The World Allergy Organization (WAO) Guidelines for the assessment and management of anaphylaxis provide a unique global perspective on this increasingly common, potentially life-threatening disease. Recommendations made in the original WAO Anaphylaxis Guidelines remain clinically valid and relevant, and are a widely accessed and frequently cited resource. In this 2015 update of the evidence supporting recommendations in the Guidelines, new information based on anaphylaxis publications from January 2014 through mid- 2015 is summarized. Advances in epidemiology, diagnosis, and management in healthcare and community settings are highlighted. Additionally, new information about patient factors that increase the risk of severe and/or fatal anaphylaxis and patient co-factors that amplify anaphylactic episodes is presented and new information about anaphylaxis triggers and confirmation of triggers to facilitate specific trigger avoidance and immunomodulation is reviewed. The update includes tables summarizing important advances in anaphylaxis research.