Increased risk of psoriasis

Background: Several cases of herpes zoster-induced psoriasis have been reported in the literature. Objective: Our nationwide retrospective cohort study is designed to examine the risk association between herpes zoster and psoriasis. Methods: From the Taiwan National Health Insurance Research Database, 26,623 patients from 1999 to 2013 with a diagnosis of herpes zoster and no prior history of psoriasis were selected as the study subjects. The control group was established during the study period from those without a herpes zoster diagnosis and was propensity score matched to minimize confounding factors. Both cohorts were followed for cases of psoriasis development. Data analysis was done via Kaplan–Meier analysis and Cox Proportional-Hazards Models. Results: Comparing the study group to control, the adjusted hazard ratio was 1.66 (95% CI, 1.31–2.13: p < 0.05) after adjusting for covariates (age, gender, urbanization, selected comorbidities and selected medications use). Statistical analysis found no interaction effect among herpes zoster and other covariates for risk modification of psoriasis development. Conclusion: This study demonstrated an increased risk of psoriasis in patients diagnosed with herpes zoster.