Anaphylaxis is a severe, potentially fatal, and systemic allergic reaction. Previous studies document increasing trends in incidence rates of anaphylaxis-related events in Western countries, yet little is known about the incidence and trend of anaphylaxis in Asia. Dr. Hui-Ju Tsai from the Institutes of Population Health Sciences and her collaborators at Chang Gung Memorial Hospital and National Cheng Kung University investigated time trends in the incidence rate of anaphylaxis using a representative nationwide sample of an Asian population from Taiwan’s National Health Insurance Research Database (NHIRD) from 2001 to 2013. They examined the effect of age and gender on having an anaphylactic episode, and evaluated the trends of severity of anaphylactic episodes in an Asian population.
A total of 2,496 patients (mean age, 45.11 years; 56% male) with first-time anaphylaxis were identified during 34,430,000 person-years of observation time. The overall incidence of anaphylaxis was 7.25 (95% confidence interval (CI) = 6.97-7.53) per 100,000 person-years, increasing from 4.79 in 2001 to 8.20 in 2013, with an incidence rate ratio (IRR) of 1.05 (95%CI = 1.04-1.06). Over the 13-year period, the increasing trends were found in incident diagnosis of anaphylaxis-related outpatient or emergency department visits (IRR = 1.06, 95%CI = 1.05-1.08) and admissions to intensive care units (IRR = 1.06, 95%CI = 1.03-1.10), whereas the trends in incidence of anaphylaxis-related hospitalizations remained steady. The proportion of patients requiring hospitalizations among all patients with anaphylaxis (p _trend = 0.01), as well as the proportion requiring intensive care treatment among patients who were hospitalized (p _trend = 0.01), both increased with age.
Dr. Tsai’s findings suggested the incidence rate of anaphylaxis in Taiwan has increased at an average rate of 5% annually since 2001, paralleling the rising trends in several Western countries, which highlighted the necessity of disentangling the potential reasons responsible for the rising incidence of anaphylaxis in Taiwan and other countries.
Citation: Yao, TC; Wu, AC; Huang, YW; Wang, JY; Tsai, HJ. Increasing trends of anaphylaxis-related events: An analysis of anaphylaxis using nationwide data in Taiwan, 2001-2013. World Allergy Organization Journal. 2018 Oct 10;11:Article number 23.