Anaphylaxis in a country where Asia and Europe meet: Evaluation according to World Allergy Organization (WAO) and European Academy of Allergy and Clinical Immunology (EAACI) diagnostic criteria.

Background: Anaphylaxis is an acute-onset, life-threatening clinical emergency involving more than one system. The World Allergy Organization (WAO) published anaphylaxis guidelines in 2020. The European Academy of Allergy and Clinical Immunology (EAACI) published anaphylaxis guidelines in 2021 and reviewed the diagnosis of anaphylaxis, risk factors, comorbid diseases, treatment management, and prevention studies.In this study, clinical features, demographic characteristics, risk factors, treatment management, and evaluations according to EAACI and WAO diagnostic criteria were analysed in patients diagnosed with anaphylaxis. In this way, it was aimed to provide a perspective on the diagnosis, etiology, and treatment management in patients with anaphylaxis and to open a window for new studies. Methods: We retrospectively analysed the data recording system of patients who were evaluated with a history of systemic allergic reaction in the Allergy and Immunology outpatient clinic of our tertiary referral hospital in a ninety-month period between January 2016 and June 2023. The total number of patients admitted to our Allergy and Immunology Clinic between January 2016 and June 2023 was 14,9425. Among these patients, 1032 patients were evaluated in the outpatient clinic according to the ICD-10 (International Statistical Classification of Diseases and Related Health Problems) coding system and diagnosed as T78.2 Anaphylaxis by Allergy and Immunology Specialist. Each patient file was re-evaluated by the authors of the study and 689 eligible patients were included. Results: Included in the study were 689 patients. The mean age of the patients was 46.2 ± 14.2 (35-57) years. 64.4% (n = 444) of the patients were female. Venom, drugs, and food were the 3 leading causes of anaphylaxis. In our study, younger age was determined as a statistically significant risk factor for food-induced anaphylaxis, female gender for drug-induced anaphylaxis and male gender for venom-induced anaphylaxis. (p < 0.001) If the cause of anaphylaxis can be identified, such as venom, drug or food, the frequency of anaphylaxis decreases statistically significantly compared to idiopathic anaphylaxis. (p < 0.001) The rate of acute hypotension, bronchospasm, or laryngeal involvement without skin involvement according to WAO and the rate of WAO severity classification grade 5 were significantly higher in patients who developed anaphylaxis due to venom compared to other patients (p < 0.001). The rate of Grade 3 in the EAACI classification was significantly higher in patients who developed anaphylaxis due to venom compared to other cases (p < 0.001). Conclusion: Our study was conducted in a city such as Istanbul, which connects both Asian and European continents. Moreover, it is important because it was conducted in a centre with the highest number of Allergy and Immunology outpatients per year in our country. It is important because it gives the prevalence of anaphylaxis and emphasises the risk factors for each allergen separately.