Risk of Psoriasis in Patients with Polycystic Ovary Syndrome: A National Population-Based Cohort Study.

Both polycystic ovary syndrome (PCOS) and psoriasis are associated with insulin resistance and metabolic syndrome. Nonetheless, the incidence of psoriasis in patients with PCOS is unclear. We used the Longitudinal Health Insurance Research Database (LHID) in Taiwan from 2000 to 2012 to perform a retrospective population-based cohort study to elucidate the occurrence of psoriasis in PCOS patients. Patients with PCOS without psoriasis in the index year (the year of PCOS diagnosis) were recruited as the PCOS group. Those without PCOS nor psoriasis (control group) were selected using propensity score matching at a ratio of 4:1. Hazard ratios (HRs) were obtained using the Cox proportional hazards regression model. In total, 4707 and 18,828 patients were included in the PCOS and control groups, respectively. The incidence rates of psoriasis in the control and PCOS groups were 0.34 and 0.70 per 1000 person-years, respectively. The risk of psoriasis was higher in the PCOS group by an HR of 2.07 (95% confidence interval [CI] = 1.25-3.43) compared with the control group. In conclusion, the incidence of psoriasis in the PCOS group was higher than that in the control group. Further studies should be conducted to investigate the mechanism underlying the association, and to benefit the long-term management of patients with PCOS.