Association of autoimmune diseases with oral lichen planus: a cross-sectional, clinical study.

BACKGROUND: The aim of this study was to investigate the association between autoimmune disease and oral lichen planus (OLP), comparing OLP patients with a control population. METHODS: This cross-sectional clinical study evaluated the prevalence of autoimmune diseases in male and female patients with OLP. The variables analysed were age, sex, tobacco and alcohol consumption, the clinical form of OLP, time of evolution and the presence of autoimmune diseases. RESULTS: Autoimmune diseases were present in 7% of OLP patients (10/130) and 4% of the control group (6/130) without statistically significant difference (P = 0.67). The estimated odds ratios (with 95% confidence intervals) of the presence of autoimmune disease in OLP sufferers was 1.033 (0.97-1.10). A logistic regression model for presence/absence of the risk autoimmune disease found statistically significant differences in relation to age. CONCLUSIONS: At present, there is no definitive hypothesis that explains the coexistence of OLP and autoimmune disease; further research is required into the mechanisms whereby this coexistence occurs.