Guia prático de urticária aguda / Practical guide to acute urticaria

A urticária aguda é uma causa frequente de consulta com alergistas, caracterizada por urticas e/ou angioedema. Embora autolimitada e benigna, pode causar desconforto significativo e raramente representar uma doença sistêmica grave ou reação alérgica com risco de vida. Nesta revisão, elaborada pelo Departamento Científico de Urticária da Associação Brasileira de Alergia e Imunologia, foram abordadas as principais questões referentes ao tema para auxiliar o médico especialista e generalista.

Acute urticaria is a frequent cause of consultations with allergists, being characterized by wheals and/or angioedema. Although self-limited and benign, it may cause significant discomfort and uncommonly represent a serious systemic disease or life-threatening allergic reaction. In this review prepared by the Urticaria Scientific Department of the Brazilian Association of Allergy and Immunology, the main questions about this topic are addressed to help specialists and general practitioners.

Onset of Nut Allergy in a Pediatric Cohort: Clinical and Molecular Patterns in the AFRUSEN Study

Background: Nut allergy is a growing problem, yet little is known about its onset in children. Objective: To characterize the onset of nut allergy in children in southern Europe. Methods: The study population comprised consecutive patients up to 14 years of age who visited allergy departments with an initial allergic reaction to peanut, tree nut, or seed. The allergy work-up included a clinical history, food challenge, skin prick testing, determination of whole-extract sIgE, and ImmunoCAP ISAC-112 assay. Results: Of the 271 children included, 260 were first diagnosed with nut allergy at a mean age of 6.5 years and at a mean (SD) of 11.8 (21.2) months after the index reaction. The most common culprit nuts at onset were walnut (36.5%), peanut (28.5%), cashew (10.4%), hazelnut (8.5%), pistachio (5.4%), and almond (5%). Onset of peanut allergy was more frequent in children ≤6 years and walnut in those aged >6 years (P=.032). In 65% of cases, the allergic reaction occurred the first time the patient consumed the nut, and 35% of reactions were anaphylactic. Overall, polysensitization to nuts was detected by skin prick testing in 64.9% of patients, although this rate was lower among walnut-allergic children (54.7%) and peanut-allergic children (54.1%) (P<.0001). Sensitization to 2S albumins was predominant (75%), especially Jug r 1 (52.8%), whereas sensitization to lipid transfer proteins was less relevant (37%). Conclusion: In the population we assessed, the onset of nut allergy occurred around 6 years of age, slightly later than that reported in English-speaking countries. Walnut was the main trigger, followed by peanut. 2S albumin storage proteins, especially Jug r 1, were the most relevant allergens. This study will help guide management and may contribute to preventive strategies in pediatric nut allergy (AU)

Antecedentes: La alergia a frutos secos es un problema creciente. Sin embargo, existe poca información relativa al inicio de su establecimiento en la población infantil. Objetivos: Describir el debut de alergia a frutos secos en niños del sur de Europa. Métodos: Se incluyeron pacientes de hasta 14 años que acudieron de forma consecutiva a la consulta de alergia debido a una reacción inicial con cacahuete, frutos secos o semillas. El estudio alergológico incluyó realización de historia clínica, provocación oral, prueba intraepidérmica (SPT), determinación de IgE específica para extracto completo y mediante ImmunoCAP ISAC-112. Resultados: De los 271 niños incluidos, 260 se diagnosticaron de alergia a frutos secos por primera vez a los 6,5 años de media, habiendo tenido la reacción índice 11,8 (±21,2SD) meses antes. Los frutos secos responsables en el debut fueron nuez (36,5%), cacahuete (28,5%), anacardo (10,4%), avellana (8,5%), pistacho (5,4%) y almendra (5%). La instauración de la alergia a cacahuete fue más frecuente en niños ≤6 años y para nuez en >6 años (p=0,032). En el 65% de los casos, la reacción alérgica sucedió en la primera vez en que el paciente consumía el fruto seco, y el 35% de las reacciones fueron anafilaxia. En conjunto, la polisensibilización a frutos secos se identificó en el 64,9% de los pacientes, aunque este porcentaje fue significativamente inferior en niños alérgicos a nuez (54,7%) y cacahuete (54,1%) (p<0,0001). La sensibilización a albúminas 2S fue predominante (75%), especialmente a Jug r 1 (52,8%), mientras que la identificación de LTP fue menos relevante (37%). Conclusión: En nuestra población, el debut de alergia a frutos secos sucedió alrededor de los 6 años de edad, ligeramente más tardío al reportado en países anglosajones. La nuez fue el principal desencadenante, seguido de cacahuete, y las albúminas de almacenamiento 2S, especialmente Jug r 1, fueron los alérgenos más relevantes (AU)

Nut Allergy: Clinical and Allergological Features in Italian Children.

BACKGROUND: Nut allergies are an increasingly frequent health issue in the pediatric population. Tree nuts (TN) and peanuts are the second cause of food anaphylaxis in Italy. Unfortunately, knowledge of the clinical characteristics of a TN allergy in Italian children is limited. Our study aimed to identify the clinical and allergological characteristics of Italian children with a nut allergy (TN and peanut). METHODS: A retrospective observational analysis was performed on the clinical charts of children with a history of nut reaction referred to the allergy unit of the hospital from 2015 to 2019. The studied population was represented by children with a confirmed nut allergy based on positive prick by prick and/or serum-specific IgE to nut plus a positive nut oral food challenge. Demographic, clinical, and allergological features were studied and compared among different nuts. RESULTS: In total, 318 clinical charts were reviewed. Nut allergy was confirmed in 113 patients. Most patients (85/113, 75%) had a familial history of allergy and/or a concomitant allergic disorder (77/113, 68%). Hazelnut and walnut were the more common culprit nuts observed in allergic children. Anaphylaxis was the first clinical manifestation of nut allergy in a high percentage of children (54/113, 48%). The mean age of the first nut reaction was statistically higher with pine nuts. Over 75% of children reported a single nut reaction. During the OFCs, the signs and symptoms involved mainly the gastrointestinal system (82/113, 73%) and resolved spontaneously in most cases. Severe reactions were not frequent (22/113, 19%). CONCLUSION: To our knowledge, this is the first Italian study that provided a comprehensive characterization of children with a nut allergy. These results are important for clinicians treating children with a nut allergy.

Correlação entre o autodiagnóstico de alergia alimentar e a presença de IgE específica / Correlation between self-diagnosis of food allergy and presence of specific IgE

Introdução: Nos últimos anos a prevalência de alergia alimentar tem aumentado, contudo, o número de autodiagnósticos errados, também. Essa superestimação dos diagnósticos, frequentemente, culmina em dietas restritivas desnecessárias que podem, muitas vezes, ocasionar mais danos do que benefícios para a saúde. Objetivo: Avaliar a relação entre o autodiagnóstico de alergia alimentar e a presença de IgE específica para o referido alimento. Método: Trata-se de um estudo transversal e observacional que avaliou 100 pacientes que aceitaram participar da pesquisa, com idade entre 18 e 75 anos, por meio de um questionário próprio para investigação do autodiagnóstico de doenças alérgicas e um teste cutâneo de leitura imediata ou prick test para detecção de IgE específica para alimentos que podem induzir a uma reação alérgica. Resultados: Foram aplicados e analisados 100 questionários em voluntários na faixa etária de 18 a 75 anos. Destes, 35 pacientes afirmaram ter alergia alimentar durante a aplicação do questionário. Apenas 10 tiveram resultado positivo ao prick test. A maioria dos resultados positivos no prick test estavam associados ao camarão, ao amendoim e ao caranguejo. Conclusão: O presente estudo evidenciou uma importante superestimação do número de autodiagnósticos de alergias alimentares, sendo o número de pacientes que se autodeclararam alérgicos a alimentos consideravelmente maior do que os resultados positivos no prick test. Constata-se que é necessário mais estudos que possuam em sua metodologia informações pré e pós-testes diagnósticos de alergia alimentar, para uma correta avaliação da proporção de casos.

Introduction: In recent years, the prevalence of food allergy has increased, as well as the number of incorrect self-diagnoses. This overestimation of diagnoses often culminates in unnecessary restrictive diets that may cause more harm than benefits to health. Objective: To evaluate the relationship between self-diagnosis of food allergy and the presence of specific IgE for that food. Method: This is a cross-sectional and observational study that evaluated 100 patients who agreed to participate in the research, aged between 18 and 75 years. A questionnaire was used to investigate the self-diagnosis of allergic diseases, and a skin prick test was used to detect food-specific IgE that may induce an allergic reaction. Results: One hundred questionnaires were administered and analyzed in volunteers aged from 18 to 75 years. Of these, 35 patients claimed to have food allergy during the administration of the questionnaire. Only 10 tested positive on the prick test. Most positive prick test results were associated with shrimp, peanut, and crab. Conclusion: The present study showed an important overestimation of the number of self-diagnosed food allergies, as the number of patients who self-reported being allergic to food was considerably greater than that of positive prick test results. More studies that have in their methods pre- and post-diagnostic information from food allergy tests are needed for a correct assessment of the proportion of cases.

Tree nuts allergy: knowledge, gaps and practical implications

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Phenotypical characterization of tree nuts and peanut allergies in east Mediterranean children

INTRODUCTION/OBJECTIVES: The characteristics of tree nuts (TNs) and peanut (PN) allergies vary in different regions of the world. We aim to identify the characteristics of TNs/PN allergies in Turkish children. Patients and METHODS: A total of 227 children [4.8 (3.2-6.8) years] with TN and/or PN allergies were included. The phenotypical features of TNs/PN allergic children and the risk factors for multiple TNs/PN allergies were evaluated. RESULTS: Allergy to TNs/PN developed at a median age of 12.0 (10.0-18.0) months. The most common TNs/PN responsible for food allergies were the hazelnut (63.9%) and the pistachio (54.6%). Of TNs/PN allergic children, 54.2% experienced reactions with at least two types of. Current ages 6-10 years [OR:2.455, 95% CI:1.255-4.852, p = 0.009] and family history of atopy [OR:2.156, 95% CI:1.182-3.932, p = 0.012] were the risk factors for multiple TNs/PN allergies. Most of the patients with cashew nut and pistachio allergies exhibited co-sensitization and co-allergy to both of these TNs/PN. Although the rarest TNs/PN allergy was seen with almond, the possibility of allergy to other TNs or PN was highly increased in the patients with almond allergy compared to other TNs/PN. CONCLUSIONS: Children with TNs/PN allergy living in an East Mediterranean region differ from the counterparts living in Western countries by an earlier age of onset of the TNs/PN allergy symptoms, increasing possibility to have multiple TNs/PN allergy at older ages, and different spectrum of TN/PN allergies (hazelnut followed by pistachio/cashew) that all indicate the consumption habits which are important determinants of TN/PN allergy development

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Consenso Brasileiro sobre Alergia Alimentar: 2018 - Parte 1 - Etiopatogenia, clínica e diagnóstico. Documento conjunto elaborado pela Sociedade Brasileira de Pediatria e Associação Brasileira de Alergia e Imunologia / Brazilian Consensus on Food Allergy: 2018 - Part 1 - Etiopathogenesis, clinical features, and diagnosis. Joint position paper of the Brazilian Society of Pediatrics and the Brazilian Association of Allergy and Immunology

A alergia alimentar é definida como uma doença consequente a uma resposta imunológica anômala, que ocorre após a ingestão e/ou contato com determinado(s) alimento(s). Atualmente é considerada um problema de saúde pública, pois a sua prevalência tem aumentado no mundo todo. É um capítulo à parte entre as reações adversas a alimentos, e de acordo com os mecanismos fisiopatológicos envolvidos, essas reações podem ser imunológicas ou não-imunológicas. Em geral, a alergia alimentar inicia precocemente na vida com manifestações clínicas variadas na dependência do mecanismo imunológico envolvido. A anafilaxia é a forma mais grave de alergia alimentar mediada por IgE. Conhecimentos recentes permitiram a melhor caracterização da Síndrome da enterocolite induzida por proteína alimentar (FPIES), assim como da esofagite eosinofílica. Vários fatores de risco, assim como novos alérgenos alimentares, têm sido identificados nos últimos anos. Tomando-se como ponto de partida o "Consenso Brasileiro sobre Alergia Alimentar: 2007" foi realizada revisão e atualização dos conceitos apresentados por grupo de alergologistas, gastroenterologistas, nutrólogos e pediatras especializados no tratamento de pacientes com alergia alimentar. Novos conceitos foram apresentados sobretudo pela melhor caracterização. O objetivo desta revisão foi elaborar um documento prático capaz de auxiliar na compreensão dos mecanismos envolvidos na alergia alimentar, assim como dos possíveis fatores de risco associados à sua apresentação, bem como sobre a sua apresentação clínica.

Food allergy is defined as a disease resulting from an anomalous immune response that occurs after ingestion of and/or contact with certain foods. It is currently considered a public health problem because of its increased prevalence worldwide. Food allergy is a major entity among adverse reactions to foods; depending on the pathophysiological mechanisms involved, these reactions may be immunological or non-immunological. In general, food allergy starts early in life with varied clinical manifestations depending on the immune mechanism involved. Anaphylaxis is the most severe form of IgE-mediated food allergy. Recent knowledge has allowed to better characterize food protein-induced enterocolitis syndrome (FPIES), as well as eosinophilic esophagitis. Several risk factors as well as new food allergens have been identified in recent years. Taking the 2007 Brazilian Consensus on Food Allergy as a starting point, the concepts presented were reviewed and updated by a group of allergologists, gastroenterologists, nutrologists and pediatricians specialized in the treatment of patients with food allergy. The objective of this review was to develop a hands-on document capable of helping improve the understanding of the mechanisms involved in food allergy, possible associated risk factors, as well as clinical presentation.

An Analysis of "Natural" Food Litigation to Build a Sesame Allergy Consumer Class Action.

In a world where food allergy is still an incurable disease, law and regulation stand as necessary mechanisms to provide food-allergic consumers with the information they need to protect their health. The Food Allergen Labeling and Consumer Protection Act of 2004 provided specific labeling requirements for the "Top Eight" allergens in the U.S.: milk, soy, gluten, egg, tree nut, peanut, fish, and Crustacean shellfish. Since then, sesame has become more prevalent as an allergen and remains just as dangerous, inducing anaphylactic shock in some sesame-allergic individuals. Yet sesame remains unregulated, despite advocates and congressional members arguing for its inclusion. This note entertains one solution to this problem by exploring the most strategic way to bring a sesame allergy class action against a private food company under California's consumer protection statutes. Because this kind of class action does not have much, if any, precedent, this note analyzes the basic, preliminary issues that any litigant would have to navigate around to certify a class, including preemption, standing, and the claim itself, by focusing on how courts have examined these issues in the recent "natural" class action litigation. It also analyzes the legal, moral, and practical aspects of choosing a type of relief, as well as whom to include in the class. Finally, this note briefly considers how FDA itself can ensure sesame is regulated on the labels of food products, given that some of the legal issues may well be insurmountable for this particular class action. This note explores the potential solutions to difficult legal hurdles in constructing a sesame allergy class action, arguing that litigating a sesame allergy class action­even if it is not ultimately successful­could start a productive conversation that might lead Congress or FDA to provide greater public health and consumer protection for those with sesame allergy.

Genetic variation at the Th2 immune gene IL13 is associated with IgE-mediated paediatric food allergy.

BACKGROUND: Food allergies pose a considerable world-wide public health burden with incidence as high as one in ten in 12-month-old infants. Few food allergy genetic risk variants have yet been identified. The Th2 immune gene IL13 is a highly plausible genetic candidate as it is central to the initiation of IgE class switching in B cells. OBJECTIVE: Here, we sought to investigate whether genetic polymorphisms at IL13 are associated with the development of challenge-proven IgE-mediated food allergy. METHOD: We genotyped nine IL13 "tag" single nucleotide polymorphisms (tag SNPs) in 367 challenge-proven food allergic cases, 199 food-sensitized tolerant cases and 156 non-food allergic controls from the HealthNuts study. 12-month-old infants were phenotyped using open oral food challenges. SNPs were tested using Cochran-Mantel-Haenszel test adjusted for ancestry strata. A replication study was conducted in an independent, co-located sample of four paediatric cohorts consisting of 203 food allergic cases and 330 non-food allergic controls. Replication sample phenotypes were defined by clinical history of reactivity, 95% PPV or challenge, and IL13 genotyping was performed. RESULTS: IL13 rs1295686 was associated with challenge-proven food allergy in the discovery sample (P=.003; OR=1.75; CI=1.20-2.53). This association was also detected in the replication sample (P=.03, OR=1.37, CI=1.03-1.82) and further supported by a meta-analysis (P=.0006, OR=1.50). However, we cannot rule out an association with food sensitization. Carriage of the rs1295686 variant A allele was also associated with elevated total plasma IgE. CONCLUSIONS AND CLINICAL RELAVANCE: We show for the first time, in two independent cohorts, that IL13 polymorphism rs1295686 (in complete linkage disequilibrium with functional variant rs20541) is associated with challenge-proven food allergy.

Phenotypical characterization of peanut allergic children with differences in cross-allergy to tree nuts and other legumes.

BACKGROUND: Peanut allergy in children is often associated with allergies to tree nuts and/or legumes. The aim of this study was to analyze in cluster a cohort of children allergic to peanuts and assessed for cross-reactivity to nuts and legumes and to identify different phenotypes. METHODS: We included retrospectively 317 children with peanut allergy evaluated at the Allergy Unit of the Saint Vincent Hospital of Lille in the last 12 years. A complete workup for peanut allergy and nuts and legumes was carried out for each patient. A hierarchical agglomerative clustering method was used to search for clusters of individuals in the evaluated cohort. RESULTS: Cross-allergy to TN and/or other legumes was identified in 137 patients (43.2%), atopic dermatitis being a major risk factor (adjusted OR = 16 [95% CI: 7.4-37]; p < 0.001). Three phenotypes emerged from cluster analysis. Cluster 1 (72 patients) is characterized by high level of rAra h 2, low threshold reactive doses for peanut and high proportion of asthma; Cluster 2 (93 patients) is characterized by high threshold reactive doses for peanut and the lowest proportion of cross-allergy to TN and/or legumes; Cluster 3 (152 patients) has a high risk of cross-allergy to TN and/or legumes and most patients suffer from eczema. CONCLUSIONS: The three phenotypes highlighted by this study could be useful to identify children with high risk of cross-allergic reaction to TNs and legumes early after PA diagnosis.

A multicenter study on anaphylaxis caused by peanut, tree nuts, and seeds in children and adolescents.

Peanut (PN) and tree nuts (TNs) are common causes of anaphylaxis in Western countries, but no information is available in Korea. To feature clinical characteristics of anaphylaxis caused by PN, TNs, and seeds, a retrospective medical record review was performed in 14 university hospitals in Korea (2009-2013). One hundred and twenty-six cases were identified, with the mean age of 4.9 years. PN, walnut (WN), and pine nut accounted for 32.5%, 41.3%, and 7.1%, respectively. The median values of specific IgE (sIgE) to PN, WN, and pine nut were 10.50, 8.74, and 4.61 kUA /l, respectively. Among 50 cases managed in the emergency department, 52.0% were treated with epinephrine, 66.0% with steroid, 94.0% with antihistamines, 36.0% with oxygen, and 48.0% with bronchodilator. In conclusion, WN, PN, and pine nut were the three most common triggers of anaphylaxis in Korean children, and anaphylaxis could occur at remarkably low levels of sIgE.

Differences in phenotype, homing properties and suppressive activities of regulatory T cells induced by epicutaneous, oral or sublingual immunotherapy in mice sensitized to peanut.

Allergen-specific immunotherapy has been proposed as an attractive strategy to actively treat food allergy using the following three different immunotherapy routes: oral (OIT), sublingual (SLIT) and epicutaneous (EPIT) immunotherapy. Regulatory T cells (Tregs) have been shown to have a pivotal role in the mechanisms of immunotherapy. The aim of this study was to compare the phenotype and function of Tregs induced in peanut-sensitized BALB/c mice using these three routes of treatment. We show that although EPIT, OIT and SLIT were all able to effectively desensitize peanut-sensitized mice, they induced different subsets of Tregs. Foxp3+ Tregs were induced by the three treatment routes but with greater numbers induced by EPIT. EPIT and OIT also increased the level of LAP+ Tregs, whereas SLIT induced IL-10+ cells. The suppressive activity of EPIT-induced Tregs did not depend on IL-10 but required CTLA-4, whereas OIT acted through both mechanisms and SLIT was strictly dependent on IL-10. Moreover, the three routes influenced the homing properties of induced Tregs differently, with a larger repertoire of chemokine receptors expressed by EPIT-induced Tregs compared with OIT- and SLIT- induced cells, resulting in different protective consequences against allergen exposure. Furthermore, whereas OIT- or SLIT-induced Tregs lost their suppressive activities after treatment was discontinued, the suppressive activities of EPIT-induced Tregs were still effective 8 weeks after the end of treatment, suggesting the induction of a more long-lasting tolerance. In summary, EPIT, OIT and SLIT mediated desensitization through the induction of different subsets of Tregs, leading to important differences in the subsequent protection against allergen exposure and the possible induction of tolerance.

Prevalence of Peanut, Tree Nut, Sesame, and Seafood Allergy in Mexican Adults.

OBJECTIVE: To identify the prevalence of perceived and probable allergic reactions to peanuts, tree nuts, sesame seed, or seafood and its association with the personal history of allergic disease. METHODS: A cross-sectional study was performed in four cities of the metropolitan area of Guadalajara, located in western Mexico. Through sampling by gender and age, 1,126 subjects were included. Using a structured questionnaire, we investigated: (i) history of atopic disease, (ii) perception of allergic reaction after food intake, and (iii) probable allergic reaction to peanuts, tree nuts, sesame, or seafood. Prevalence and 95% confidence intervals were calculated. A multivariate analysis of factors associated to perceived and probable allergic reactions to food was performed by logistic regression. RESULTS: Men were 49.8%; mean age was 28.1 years; personal history of atopic disease included: allergic rhinitis (6.9%), asthma (6.8%), and atopic dermatitis (3.8%). Prevalence of perceived and probable food allergy was, respectively: pecan 0.4 and 0.3%; peanut 0.6 and 0.6%; sesame 0.1 and 0.1%; shellfish 4.2 and 4.0% (mainly shrimp); mollusk 0.8 and 0.7%; fish 1.4 and 1.2%. Asthma was significantly associated with perceived and probable allergy to pecans, peanuts, fish, or seafood. Atopic dermatitis was associated with perceived and probable allergic reaction to sea snail, seafood, shellfish, or mollusks. Finally, allergic rhinitis was associated with allergy to shrimp and crustaceans. CONCLUSIONS: This study shows that the prevalence of peanut, tree nut, sesame seed, and seafood allergy in this Mexican population is similar to that reported in developed countries.