Allergies are still on the rise? A 6-year nationwide population-based study in Korea.

BACKGROUND Some western countries recently have shown a slowdown in the incidence of allergic diseases after worldwide increasing trends, but there are few data from Asian populations concerning changing trend of allergic diseases. We evaluated the recent trends in the prevalence of asthma and other allergic diseases in Korea. METHODS From the database of Korean National Health Insurance, a nationwide diagnostic data from 2009 to 2014 were extracted and the national prevalence was analyzed. RESULTS The prevalence per 1000 people of atopic dermatitis, allergic rhinitis, and asthma in 2014 was 19.0, 133.1, and 36.3, respectively. The prevalence of three diseases was highest in the age group under 10 as, 95.0, 384.1, and 132.1 per 1000 people, while the prevalence in the over-10-year-group was only 11.6, 109.5, and 27.3, respectively. The prevalence of atopic dermatitis and allergic rhinitis gradually decreased with older age, but the prevalence of asthma showed a re-increasing pattern from the age group 30-39 and reached another peak for the age group 70-79. During the study period, the prevalence of asthma and atopic dermatitis showed decreasing tendency. In contrast, the prevalence of allergic rhinitis steadily increased until 2013, especially in the age group under 10. CONCLUSIONS The national prevalence of atopic dermatitis, and asthma did not show noticeable increase any more in Korea. However, the prevalence of allergic rhinitis still on the rise until recently, especially in the age group under 10. This is the first report in Asia suggesting a slowdown of the incidence of allergic diseases.