Oral Lichen Planus and Systemic Diseases

The mouth is referred to as "the mirror of health and disease in the body." This review critically examines the comorbidity between systemic diseases and oral lichen planus, an autoimmune disorder affecting the oral mucosa with malignant potential and of high worldwide prevalence. Research has indicated that patients with oral lichen planus are significantly predisposed to diabetes mellitus (pooled proportion [PP] = 9.77%, odds ratio [OR] = 1.64, P < 0.001), Hashimoto thyroiditis (PP = 8.60%, OR = 2.2, P < 0.001), hypothyroidism (PP = 8.14%, OR = 1.65, P = 0.02), hyperthyroidism (PP = 2.84%, OR = 2.11, P = 0.007), celiac disease (PP = 7.14%, OR = 4.09, P < 0.001), hepatitis C (PP = 7.14%, OR = 4.09, P < 0.001), hepatitis B (PP = 3.90%, OR = 1.62, P = 0.02), steatohepatitis (PP = 7.06%, OR = 5.71, P = 0.05), liver cirrhosis (PP = 4.27%, OR = 5.8, P = 0.002), depression (PP = 31.19%, OR = 6.15, P < 0.001), anxiety (PP = 54.76%, OR = 3.51, P < 0.001), and stress (PP = 41.10%, OR = 3.64, P = 0.005). A good knowledge of these associations may assist primary care physicians, dentists, and other oral health professionals involved in the management of patients with oral lichen planus since many patients may be unaware of these associations and could have an impact on their general health. Some of these diseases, such as diabetes, have a role in the development of oral lichen planus. In addition, most of these comorbidities act as risk factors for cancer of different locations: liver, thyroid, small intestine, and the oral cavity. Current evidence indicates a high prevalence and a higher risk of systemic diseases in patients with oral lichen planus compared with the general population. Future research is recommended to increase our knowledge of pathobiology and clinical management of these associations.