Background: Anaphylaxis is the most severe manifestation of an IgE-dependent allergy. Standardized acquired clinical data from large cohorts of well-defined cases are not available. The aim of this study was to analyse the symptom profile and risk factors of anaphylaxis in a large Central European cohort. Methods: We acquired data from patients in Germany, Austria and Switzerland who experienced a severe allergic reaction defined by the onset of severe pulmonary and/or severe cardiovascular symptoms. The data were gained via an online questionnaire from 83 medical centres specialized in allergy. Data were collected from 2006 to 2010 and analysed by using a multinomial regression model. Results: A total of 2012 paediatric and adult patients were included into the present analysis. The skin (84%) was the most frequently affected organ followed by the cardiovascular (72%) and the respiratory (68%) system. The regression model analysing the onset of cardiovascular versus respiratory symptoms revealed a strong impact of age (adjusted OR = 6.08; 95% CI, 3.35-11.01; P < 0.001). Furthermore, the elicitor food (adjusted OR = 0.29; 95% CI, 0.21-0.41, P < 0.001) and the presence of atopic diseases (adjusted OR = 0.54; 95% CI, 0.40-0.73, P < 0.001) were significantly associated with the onset of respiratory symptoms. Conclusion: Data from individuals who experienced anaphylaxis can support the identification of risk factors. The present study indicates that age, the elicitor itself and the presence of atopic diseases have an impact on the symptom profile of anaphylaxis. Identifying further risk factors of anaphylaxis is of significant importance for clinical practice in the future.Anaphylaxis is defined as a serious hypersensitivity reaction that is rapid in onset and may cause death (1, 2). The incidence rate of anaphylaxis varies from 7.9 to 49.8 per 10 000 personyears depending on the region, but more importantly on the definition and inclusion criteria applied (3-5). The literature citing the causes of anaphylaxis indicates that drugs, insect venom and food are the most frequent triggers (6, 7). Anaphylaxis can present with various clinical symptoms involving different organ systems including the skin, gastrointestinal and respiratory tract and the cardiovascular system. The involvement of the skin is most frequent and has been documented in 80-90% of reported episodes (8,9). The respiratory tract is affected in up to 70% of patients, and the cardiovascular system and the gastrointestinal tract have been reported to be less Abbreviations aOR(s) adjusted odds ratio(s); CI confidence interval; CVD cardiovascular diseases; ENT ear, nose and throat; IgE immunoglobulin E; SD standard deviation. Allergy 67 (2012) 691-698 © 2012 John Wiley & Sons A/S 691 Allergy Allergy 67 (2012) 691-698

Anaphylaxis is the most severe reaction of an IgE-mediated hypersensitivity. Data about affected patients may help to improve our knowledge of anaphylaxis and its medical care. We analysed data from the anaphylaxis registry of German speaking countries with regard to the provoking allergens and treatment modalities of anaphylaxis in children and adolescents. Inclusion criteria were severe systemic allergic reactions with concomitant pulmonary and/or cardiovascular symptoms. The data are collected by a password-controlled online-questionnaire. For this analysis, data of 197 reported anaphylactic reactions from children and adolescents registered between 2006 and 2009 were included. The data show that within the registered cases the most frequently affected organ systems for children and adolescents were the skin (89%) and the respiratory tract (87%) followed by symptoms of the cardiovascular system (47%) and the gastrointestinal tract (43%). The most frequent elicitors were food allergens accounting for 58% of cases, followed by insect venom (24%) and drugs (8%). The most frequent food allergens were peanuts followed by tree nuts and animal related food products. In 18% aggravating factors such as physical exercise were noted by the clinicians. 26% of the analysed patients had experienced more than one reaction. The data regarding the emergency treatment show that antihistamines (87%) and corticosteroids (85%) were often used but that adrenaline was rarely used (22% of the registered cases). Taken together these data show that the analysis of anaphylaxis by registration of affected individuals can provide data about provoking allergens and treatment measures but also suggest the impact of aggravating factors on anaphylactic reactions. The under-represented usage of adrenaline indicates the need of educational measures for patients and their physicians.

Our data show that food products are frequent elicitors of severe allergic reactions in the general population including children and adults. It unravels a strong underuse of adrenaline by emergency physicians, not reflecting treatment protocols according to the current guidelines. As data obtained from allergists reveal a different rank order of elicitors, this study suggests that food-allergic adult patients may present a risk population and should receive more attention by allergists.

Wasp and bee venom, legumes, animal proteins, and analgesic drugs were the commonest triggers of anaphylaxis. Their relative frequency was age-dependent. Epinephrine was given too rarely, as it is recommended in the guidelines for all cases of grade 2 and above.

Our data show that heat processing of HN reduces its allergenicity. SPT but also the basophil activation test can be used to determine the reactivity of an allergen extract.