Alopecia Areata Increases the Risk of Stroke: a 3-year Follow-Up Study.

The risk for stroke in alopecia areata (AA) patients is still unknown. This study aimed to investigate the risk for subsequent risk of a stroke in AA patients in a large-scale retrospective cohort study. We identified 3231 patients with AA included in the study group from 2004 to 2011 in the "Longitudinal Health Insurance Database 2000" in Taiwan. We randomly selected 16,155 matched patients as the comparison group. We individually tracked each patient for a 3-year period to identify patients who had received a diagnosis of stroke during the follow-up period. We found that incidence rates of stroke during the 3-year follow-up periods were 5.44 (95% confidence interval (CI) = 4.03~7.20) and 2.75 (95% CI = 2.30 ~ 3.27) per 1000 person-years for patients with and those without AA, respectively. Cox proportional hazard regressions showed that the adjusted hazard ratio for stroke for those patients with AA was 1.61 (95% CI = 1.13 ~ 2.30) within the follow-up period compared to the controls. We concluded that patients with AA were associated with a higher risk of stroke in the 3-year follow-up period.