Incidence of diabetes mellitus in patients with oral lichen planus.

The incidence of diabetes mellitus (DM) was studied in 40 patients with clinically and histologically verified oral lichen planus (OLP). The investigation comprised registration of previously known diabetes as well as analysis of fasting blood and urine glucose. The frequency of known diabetes was compared with the results of a sex- and age-matched control group consisting of 40 patients without any mucosal changes. Comparison was also made with the incidence of DM in general population samples. 6 of 40 OLP patients (15%) were known diabetics. Analyses of fB glucose, which in 2 cases were completed with glucose tolerance tests, revealed diabetes mellitus in a total of 11 patients (28%). According to the criteria given by WHO, 9 patients had manifest DM while 2 had DM of a latent type. The incidence of DM in the control group was 3%, which corresponds well with what has been reported for Scandinavian general populations of the same sex and age distribution. The high incidence of DM in the patients with OLP supports the hypothesis that DM may be related to the pathogenesis of OLP.