Prevalence of oral lichen planus in diabetes mellitus according to the type of diabetes.

Objective: The purpose of the present study was to determine the prevalence of oral lichen planus (OLP) in a population of patients with diabetes mellitus (DM) as compared with a control population.

Design: A clinicopathologic study.

Subjects And Methods: One hundred and thirty-nine patients with type I DM, 353 patients with type II DM and 274 controls were examined for clinical evidence of OLP. The clinical evidence of OLP in the diabetic and control patients was confirmed by histopathological examination.

Results: The prevalence of OLP in type I diabetic patients was 5.76%, in type II 2.83%, and 1.82% in the controls. The prevalence of OLP was significantly higher in patients with type I DM and slightly higher in patients with type II DM in comparison to the prevalence in the control sample.

Conclusions: The above findings and the fact that type I diabetes and OLP are characterized by autoimmune phenomena and T cell immune responses respectively, suggest that the immune system may play a critical role in the appearance of OLP in patients with type I DM.