Prevalence and incidence of chronic spontaneous urticaria in the entire Korean adult population

Background: Ethnic differences and temporal trends in the epidemiology of chronic spontaneous urticaria (CSU) are not well understood. Objectives: The aim of our study was to investigate recent trends in the prevalence and incidence of CSU among adult Korean subjects from 2006 to 2014. Methods: This study used the national health claims database of Korea, which covers nearly the entire Korean population. Data from all Koreans aged ≥20 years were included in this study. We defined a diagnosis of CSU when one of the following two criteria and a prescription criterion were met: either (1) two outpatient diagnoses of L50.1, L50.8, or L50.9; or (2) one outpatient diagnosis of L50.1, L50.8, or L50.9 plus one diagnosis of T78.3 at least 6 weeks apart within one year, and 42 days or longer prescription of an antihistamine under the diagnosis of L50.1, L50.8, or L50.9 within one year of the initial diagnosis. Age-adjusted prevalence and incidence of each year from 2006 to 2014 were calculated. Results: The annual age-adjusted prevalence and incidence of CSU were in the range of 0.16-0.45%, and 1.02-2.43 per 1,000 person-years, respectively. Women had a higher prevalence and incidence than men throughout tye years from 2006 to 2014. The prevalence and incidence of CSU consistently increased annually from 2006 to 2014. Conclusion: We presented the longitudinal prevalence and incidence of CSU in the entire adult Korean population and found recent increasing trends.