Increased incidence of chronic actinic dermatitis in relation to climate changes and air pollution during the past 15 years in Korea

Summary Background Chronic actinic dermatitis ( CAD ) develops in seasons where there is high sun exposure, such as summer, and can persistent throughout the year in severely affected cases. The authors noted that CAD prevalence increased in relation to climate changes and air pollutants. Methods We retrospectively analyzed 294 patients with newly diagnosed CAD between December 2000 and November 2016. We investigated the annual trend of sun hours, humidity, and ground‐level ozone and respirable particles ( PM 10) in Pusan, Korea; correlations between climate change and/or air pollution and the incidence of patient with CAD were analyzed. Results The incidence of patients with CAD apparently increased annually during the period of the study. The majority of patients presented in summer. Pearson's correlation analysis showed an increasing tendency of CAD occurrence to be correlated with sun hours ( R  = .706, P  = .002), ground‐level ozone ( R  = .542, P  = .03), and mean air humidity ( R  = .608, P  = .012). Inversely, PM 10 showed a negative correlation with CAD occurrence ( R  = −.713, P  = .002). The correlations identified by multiple regression analysis showed a strong positive association between the incidence of CAD and sun hours ( P  = .029) and a negative association between the incidence of CAD and PM 10 ( P  = .027) (adjusted R 2  = .778). Conclusion The increased incidence of CAD may be related to sun hours and inversely related to PM 10.