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.

Aspirin desensitization, when tolerated, was effective in patients with AERD and with poor clinical/surgical response.

Allergens produced by cockroaches (CRs) are an important cause of IgE antibody responses and asthma. Using molecular cloning and nucleic acid hybridization techniques, we have identified and sequenced several important allergens produced by the German CR (Blattella germanica) and studied their expression in the American CR (Periplaneta americana). Principal allergens include Bla g 2 (36-kD protein) and Bla g 4 (21-kD protein), to which 60–70% of CR-allergic patients make IgE antibodies. Bla g 2 is only expressed by B. germanica, whereas DNA encoding Bla g 4 is present in P. americana, but is not transcribed into mRNA. Sequence homology searches have identified Bla g 2 as an aspartic protease and Bla g 4 as a calycin. Other CR allergens that have been cloned include a glutathione transferase and a troponin. These studies will enable recombinant allergens to be expressed and used to investigate the role of CR allergens in asthma.

Objective: To study the association between atopy and variables such as weight, length, and socioeconomic level at birth and in young adulthood.Methods: A total of 2,063 subjects were investigated in a prospective birth cohort study of individuals born in Ribeirão Preto, Brazil, in 1978Brazil, in /1979, and examined at the age of 23-25 years. Skin prick tests (SPT) for eight common allergens in Brazil were performed. Subjects with a wheal reaction ≥ 3 mm to one or more of the eight allergens tested were considered to be atopic. We used the log-binomial model (generalized linear model) in order to assess the association between atopy and birth or adult variables. Results:The prevalence of positive SPT was 47.6%. Male gender was associated with an increased risk of atopy (relative risk [RR] = 1.18; 95% confidence interval [95%CI] 1.07-1.30). Low level of schooling was a protective factor against atopy, with a RR = 0.74; 95%CI 0.62-0.89. Living with a smoker in childhood was also associated with lower risk of atopy (RR = 0.87; 95%CI 0.79-0.96). Birth weight, length and order, maternal age, and intrauterine growth restriction were not associated with positive SPT. Conclusions:This study showed that male gender was associated with an increased risk of atopy. Low socioeconomic status, assessed by low level of schooling, was a protective factor against atopy. These data agree with the hygiene hypothesis.J Pediatr (Rio J). 2011;87(4):336-342: Allergens, allergy, risk factors, skin test. ResumoObjetivo: Estudar a associação entre atopia e variáveis como peso, comprimento e nível socioeconômico no nascimento e na idade adulta jovem. Métodos:Foram investigados 2.063 indivíduos em um estudo prospectivo de coorte de nascimento com indivíduos nascidos em Ribeirão Preto (SP), em 1978/1979, e examinados aos 23-25 anos de idade. Realizaram-se testes cutâneos de puntura (TCP) para oito alérgenos comuns no Brasil. Foram considerados atópicos os indivíduos que apresentaram reação papular ≥ 3 mm para um ou mais dos oito alérgenos testados. A fim de avaliar a associação entre atopia e variáveis no nascimento e na idade adulta, utilizamos o modelo log-binomial (modelo linear generalizado).Resultados: A prevalência de TCP positivo foi de 47,6%. O gênero masculino esteve associado a aumento do risco de atopia [risco relativo (RR) = 1,18; intervalo de confiança de 95% (IC95%) 1,07-1,30]. O baixo nível de escolaridade foi um fator de proteção contra atopia, com um RR = 0,74; IC95% 0,62-0,89. A convivência com um fumante na infân-cia também esteve associada a um menor risco de atopia (RR = 0,87; IC95% 0,79-0,96). Peso e comprimento ao nascer, ordem de nascimento, idade materna e restrição de crescimento intrauterino não estiveram associados a TPC positivo. Conclusões:Este estudo demonstrou que o gênero masculino esteve associado a um aumento do risco de atopia. O baixo nível socioeconômico, estabelecido pelo baixo nível de escolaridade, foi um fator de proteção contra a atopia. Esses dados estão de acordo com a teoria da higiene...