Hyun Jee Kim, Yeong Ho Kim, So Yeon Yun, Dong Soo Yu, Young Bok Lee
DOI: 10.2340/00015555-3877

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 outpatient 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 Behçet’s disease, Crohn’s disease, ulcerative colitis, and multiple sclerosis in the actinic keratosis group were not statistically significant.

The main mechanisms involved in the onset of actinic keratosis include ultraviolet-induced mutated keratinocytes and dermal inflammation. There have been no epidemiological studies identifying associations between systemic inflammatory diseases and actinic keratosis. In the current study, the population diagnosed with actinic keratosis and the control population without actinic keratosis were compared. The prevalence of rheumatoid arthritis and psoriasis was significantly higher in the actinic keratosis group than the control group. However, the proportions of Behçet’s disease, Crohn’s disease, ulcerative colitis, and multiple sclerosis in the actinic keratosis group were not statistically significant.

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