Correlation Between Oral Lichen Planus and Thyroid Diseases in China

Objectives: Oral lichen planus (OLP) is a chronic autoimmune mucocutaneous disease that most commonly affected mid-aged women with a prevalence of 1~2% in general population. The etiology and pathogenesis of OLP remains unclear, some systemic diseases such as hypertension, diabetes and chronic hepatitis may increase the risk of risk of OLP. Since the first report revealed the possible relationship between OLP and hypothyroidism in 1994, increasing studies regarding this topic have raised recently. It has been reported the correlation between OLP and thyroid disease in England, Canada, Germany and USA population, however, no evidence regarding this association in Chinese ethnic population has been available in the literature to date. The aim of this study was to evaluate the correlation of OLP and thyroid diseases in Chinese patients.
Methods: 192 OLP patients and 162 controls were recruited in this prospective case-control study. All participants were instructed to establish thyroid diseases screening including thyroid function and B ultrasound. Subjects were matched for sex and age. The prevalence of thyroid diseases in the subjects was analyzed. The odds ratio (OR) with 95% confidence intervals (CI) for the association of OLP and different types of thyroid diseases (HT, hypothyroidism, hyperthyroidism, thyroid nodule, etc) were estimated by logistic regression.
Results: The prevalence of thyroid diseases in OLP group (72.4%) was significantly higher than control group (49.4%). Among them, HT (OR=3.16 and 95% CI of 1.87-5.33) and thyroid nodule (OR=2.31 and 95% CI of 1.30-4.09) were significantly related to OLP but not hypothyroidism (OR=1.89 and 95% CI of 0.68-5.06).

Conclusions: Our study suggested the close relationship between OLP and HT，thyroid nodule in Chinese population. The possible mechanism behind this association calls for further investigation.