Objective Periodontal disease has been associated with systemic inflammation and may be a risk factor for autoimmune diseases. We evaluated the association between periodontal disease and the risk of incident psoriasis in a large prospective cohort study. Material and methods Self-reported history of periodontal bone loss, from 1998 to 2008, was evaluated as a risk factor for incident psoriasis among 60,457 women in the Nurses' Health Study. Secondary analyses examined associations between history of tooth loss and number of natural teeth and psoriasis risk. Cox proportional hazards models were used to assess multivariate estimates, adjusting for age, cigarette smoking, body mass index, alcohol intake and physical activity. Results We observed an increased multivariate risk of psoriasis for those with mild periodontal bone loss (RR 1.35, 95% CI: 1.03-1.75) and moderate to severe periodontal bone loss (RR 1.49, 95% CI: 1.08-2.05), as compared to those without periodontal bone loss, after adjusting for age, cigarette smoking, body mass index, alcohol intake, physical activity, and tooth loss. Number of natural teeth and tooth loss were not associated with risk of psoriasis in our study. Conclusion A history of periodontal bone loss may increase risk of subsequent psoriasis.

These results suggest that periodontitis is not strongly associated with CAC. This study offers some reference for the magnitude of the association between CAC and periodontitis and information regarding the minimal power necessary for future studies.