Predictors of the Severity and Serious Outcomes of Anaphylaxis in Korean Adults: A Multicenter Retrospective Case Study

PURPOSE Differences in definitions of the condition, relevant triggers, and the geographical locations of study centers, cause estimates of the prevalence of anaphylaxis to vary. Recent epidemiological data indicate that the incidence of anaphylaxis is rising. METHODS To investigate the causes and clinical features of anaphylaxis in Korean adults, factors associated with the severity of the condition, and serious outcomes, a retrospective medical record review was performed on adult patients diagnosed with anaphylaxis between 2007 and 2011 in 15 University Hospitals of South Korea. RESULTS A total of 1,806 cases (52% male, age 16-86 years) were reported. Cutaneous symptoms (84.0%), combined with respiratory (53.9%) and/or cardiovascular (55.4%) symptoms, were the most frequent presentations. Using a recognized grading system, 1,776 cases could be classified as either mild, 340; moderate, 690; or severe, 746. Although eliciting factors varied significantly by age, gender, and regional and seasonal factors, drugs (46.5%; including nonsteroidal anti-inflammatory drugs, antibiotics, and radiocontrast media) were the most common cause of anaphylaxis, followed by foods (24.2%), insect stings (16.4%), exercise (5.9%), and unknown etiology (7.0%). All of age, multi-organ involvement, a history of allergic disease, and drug-induced anaphylaxis, were significant predictors of serious outcomes requiring hospital admission or prolongation of hospital stay. Epinephrine auto-injectors were prescribed for 7.4% of reported cases. CONCLUSIONS The principal causes of anaphylaxis in Korean adults were drugs, food, and insect stings. Drug-associated anaphylaxis, a history of allergic disease, multi-organ involvement, and older age, were identified as predictors of serious outcomes.