Association of Actinic Keratosis with Rheumatoid Arthritis and Psoriasis: A Nationwide Population-Based Study in Korea

There have been no epidemiological studies identifying associations between systemic inflammatory diseases and actinic keratosis. This study used a large nationwide database to investigate the associations between actinic keratosis and systemic inflammatory diseases. Records of patients over 20 years of age newly diagnosed with actinic keratosis (n = 64,659) from 2012 to 2017 were analysed. A control population of individuals without actinic keratosis, matched for age, sex, and year of claim, who visited an out-patient clinic, was sampled at a ratio of 1:1 (n = 64,659). Both cohorts were analysed for the presence of systemic inflammatory diseases within at least 5 years prior to diagnosis of actinic keratosis. Patients with actinic keratosis exhibited higher odds ratios for rheumatoid arthritis (1.336; 95% confidence interval (95% CI) 1.161-1.537)) and psoriasis (1.513; 95% CI 1.435-1.595) compared with the control group on multivariate analysis. However, the proportions of Behcet's disease, Crohn's disease, ulcerative colitis, and multiple sclerosis in the actinic keratosis group were not statistically significant.

Automated summary

Using a large nationwide database, this study found that there were higher odds ratios for rheumatoid arthritis and psoriasis in patients with actinic keratosis compared to the control group. However, there were no statistically significant differences in the proportions of Behcet's disease, Crohn's disease, ulcerative colitis, and multiple sclerosis between the two groups.