Objective: To estimate the prevalence of prediabetes and diabetes in patients with oral lichen planus (OLP). Methods: Prospective cohort, including consecutive patients diagnosed clinically and histologically with OLP from 2018 to 2022. Patients and controls were matched by age and gender. Fasting plasma glucose value collection from all patients. Multivariate regression analysis evaluated the relationship between prediabetes and diabetes variables according to current diagnostic criteria. Results: The sample comprised 275 patients (207 women; 75.3%), mean age 59.60 ± 12.18 years for both groups. Prediabetes was diagnosed according to the American Diabetes Association (ADA, 100–125 mg/dL), in 21.45% of OLP patients (59/275) and 14.55% (40/275) of control patients (p = 0.035). Patients with the atrophic-erosive form exhibited stronger association with taking oral antidiabetics (p = 0.011). Multivariate analysis showed that being over >60 years and having a cutaneous location was associated with ≥3 sites (OR 1.81 and OR 2.43). ADA prediabetes and oral antidiabetics drugs increased the probability of OLP (OR 1.60 (1.04–2.51), p = 0.03 and OR 2.20 (1.18–4.69), p = 0.017) after adjustment for sex and age. Conclusions: Because glycemia 100–125 mg/dL was associated with OLP, testing serum fasting plasma glucose seems reasonable in order to prevent development of diabetes and deal with possible complications until new studies are complete.

Background: It has been reported that vitamin D deficiency may be associated with the development of oral lichen planus (OLP). Given the high prevalence of vitamin D deficiency in many countries, we sought to determine whether it constitutes a comorbidity of OLP. Methods: One hundred and twenty patients clinically and histologically diagnosed with OLP were evaluated for their serum vitamin D levels. The results were compared to results from a control series of the same number of subjects matched for age and sex. Results: Vitamin D deficiency was diagnosed in 45% (n = 54) of OLP patients and in 26.7% (n = 32) of the control group. Vitamin D supplements were being taken by 32 (26.7%) OLP patients and 15 (12.5%) subjects in the control group. A multivariate logistic regression model showed that OLP was associated with vitamin D deficiency [OR: 2.24 (1.28–3.98, p = 0.005)] and vitamin D supplementation [OR: 2.51 (1.25–5.22, p = 0.011)], even after controlling for confounding variables such as sex, age ≤60>, tobacco, and alcohol. Conclusion: The association between OLP patients and vitamin D deficiency or vitamin D supplementation suggests that further research might explore the benefits of vitamin D supplements in managing OLP patients.

Objectives: The purpose of this study was to determine the association between oral lichen planus (OLP) and the history of cancer outside of oral cavity and the predominance of its location. Methods: This case–control study included 600 OLP patients and 600 control subjects evaluated in the same section, matched for age and sex to the OLP patients. OLP patients were diagnosed clinically and histologically. Initially, the prevalence of the most frequent types of cancers was described. A Pearson chi-squared test model was used to determine the association of cancer history and OLP. It was considered statistically significant whether p value was ≤0.05. The final multivariate regression model was built after applying a backward selection method to the complete multivariate model considering the odds ratio (OR) with a 95% confidence interval (CI). Results: The history of cancer was significantly associated with OLP regardless of age, sex, tobacco and or alcohol use in both univariate [OR = 2.26 (95%CI: 1.26–4.24); p = 0.008] and multivariate analyses [OR = 2.21 (95%CI: 1.21–4.19); p = 0.012]. According to the location of cancer, there was an association between OLP and history of breast cancer [OR = 3.71 (95%CI = 1.03–13.38); p = 0.032]. Conclusions: This case–control study suggests a higher frequency of cancer, particularly breast cancer, among patients with OLP compared to the control group. Due to the study’s design and sample limitations, these findings should be interpreted cautiously. Future longitudinal, multi-institutional studies with rigorous control for cancer history and other confounding factors are essential to further explore the association between OLP and cancer, particularly breast cancer.