Epidemiology of Chronic Urticaria in Korea Using the Korean Health Insurance Database, 2010-2014

Abstract

Purpose: There are very few epidemiological studies on chronic urticaria (CU). We aimed to investigate the prevalence of CU and to depict demographics and medication patterns for the disease in a nationwide population-based study.

Methods: Data on urticaria (L50 of the International Classification of Diseases, 10th revision) from 2010 to 2014 were obtained from the Korean Health Insurance Review and Assessment Service. Algorithms designed to evaluate prescription drug claims for antihistamines were applied to identify CU.

Results: The crude prevalence of CU was 2,256.5 per 100,000 person-years and tended to increase every year. The age-standardized prevalence of CU was significantly higher in females than in males (2,466.8 vs 1,819.2 per 100,000 person-years, P<0.001). Age-specific prevalence was highest for older adults over the age of 65 years and lowest for ages 10-29 years. The median duration of CU was 591 days, and symptoms lasted for at least 1 year in 61.9% of patients. Gastrointestinal disease was the most common comorbidity in adults, whereas allergic rhinitis and common cold were more prevalent in children with CU. Around a third of CU patients were taking antihistamine treatment alone, and 70% were treated with both antihistamines and systemic corticosteroids. Cyclosporine was prescribed for 0.02% of CU patients.

Conclusions: The present study outlines recent longitudinal epidemiological data on the prevalence of CU in Korea. In light of limitations on the use of claims data, including no specific disease code for CU and a possible discordance between drug claims and the presence of urticaria symptoms, further investigations are necessary to describe the exact epidemiologic profile of CU patients.

Keywords: Urticaria; chronic; epidemiology.

Fig. 1

Algorithms for identification of CU. If subsequent visits had happened within a week, it was considered as a continuous visit for controlling the same event of urticaria. D_t represents the visit date at time t, and Pd_t means days for prescription medications at time t. Time “m” means the last visit for urticaria. CU, chronic urticaria.

Fig. 2

Crude prevalence of CU (per 100,000 person-years) over a 5-year period. There was a significant linear trend in the crude prevalence of CU over the 5-year period (P<0.001). CU, chronic urticaria.

Fig. 3

The prevalence of CU (per 100,000 person-years) specific to age and sex. CU, chronic urticaria.

Fig. 4

Distribution of CU patients according to urticaria duration. M, month; CU, chronic urticaria.