The effects of chronic periodontitis and its treatment on the subsequent risk of psoriasis.

BACKGROUND: Although psoriasis and chronic periodontitis (CP) may share an underlying immune dysregulation as part of their pathologies, to date only one small-scale cross-sectional pilot study has investigated the potential association between CP and psoriasis.

OBJECTIVES: This study aimed to investigate the subsequent risk for psoriasis following a diagnosis of CP by utilizing a cohort study design and population-based dataset in Taiwan.

METHODS: In total, 115 365 patients with CP were included in the study cohort and 115 365 patients without CP were included in the comparison cohort. We individually tracked each patient for a 5-year period to identify those who had subsequently received a diagnosis of psoriasis. A Cox proportional hazards regression was performed to compute the 5-year risk of subsequent psoriasis following a diagnosis of CP.

RESULTS: We found that the incidence rate of psoriasis during the 5-year follow-up period was 1·88 [95% confidence interval (CI) 1·77-1·99] per 1000 person-years in patients with CP and 1·22 (95% CI 1·14-1·32) per 1000 person-years in comparison patients. After censoring those who died during the follow-up period, and adjusting for monthly income and geographical region, compared with comparison patients, the hazard ratio (HR) of psoriasis for patients with CP was 1·52 (95% CI 1·38-1·70). Furthermore, the study subjects who had undergone a gingivectomy or periodontal flap operation had only a slightly higher adjusted risk of psoriasis than comparison patients (HR 1·26).

CONCLUSIONS: This study detected an increased risk for psoriasis among patients with CP. Treatment for CP attenuated, but did not nullify, the risk for subsequent psoriasis.