How Oral Lichen Planus Connects to Systemic Autoimmune Disease

A literature review recently published in the Journal of Dental Research examined current evidence on the relationship between systemic diseases and oral lichen planus (OLP), an autoimmune disorder in which CD8+ T cells target basal keratinocytes in the oral mucosa. OLP affects about 1% of the population and may also involve other mucosal sites, including the esophagus and genital mucosa. Clinically, it is defined by characteristic lace-like white lesions, supported by histopathologic findings such as basal-layer degeneration and a bandlike lymphocytic infiltrate.

OLP and Diabetes

Current literature on the relationship between OLP and diabetes is conflicting. While over 100 studies have shown a significantly higher risk of developing Type 2 diabetes, there are few studies (only five primary studies) currently available with a focus on Type 1 diabetes (T1D), which is also an autoimmune disease. The authors noted that a T1D prevalence of 1.62% was determined in OLP patients. T1D patients often present a “state of systemic autoimmunity, with a predisposition to develop multiple autoimmune diseases simultaneously; therefore, it can be suggested that the association between OLP and diabetes mellitus, especially Type 2, may be bidirectional.

OLP and Thyroid Disease

Patients with OLP have a significantly higher risk of developing thyroid disease than the general population, with meta-analysis results showing Hashimoto’s being the most prevalent form in patients with OLP. In fact, the risk of developing Hashimoto’s with OLP is 2.2x higher than in the general population. The prevalence of Graves’ disease (the result of an overactive thyroid gland) is inconclusive from current literature.

The link between Hashimoto’s and OLP may come from cross-immunity. The authors note that some studies suggest that certain thyroid proteins resemble proteins in the oral tissues, which could confuse the immune system and trigger both conditions. Another possibility is that thyroid receptor (TSHR) expression is more common in the mouth lesions of people with thyroid disease, suggesting a shared biological pathway. While larger-scale studies show that OLP and thyroid disorders frequently occur together, it still remains unclear which one comes first, or if they share an underlying autoimmune pathogenesis.

OLP and Celiac Disease

The last autoimmune disease covered in this literature review is celiac disease. “Patients with OLP suffer from celiac disease in 8.66% of cases, with a risk 18.44 times higher than the general population”. In contrast, the prevalence of celiac disease in the general population is around 1.4%. Cross-autoimmunity has been hypothesized for this phenomenon. A target enzyme in celiac disease may share the same structure homology with proteins of the mouth’s oral lining, allowing T lymphocytes activated by gluten to contribute to the pathogenesis of OLP. It has also been reported that the immune response to gluten may also attack oral mucosa, causing epithelial disruption and compromising the mucosal barrier. This process may also lead to the development of OLP, but evidence remains limited for both.

Citation

Warnakulasuriya, S., Ramos-García, P., & González-Moles, M.Á. (2025, November 18). Oral Lichen Planus and Systemic Diseases. Journal of Dental Research. Advance online publication. https://doi.org/10.1177/00220345251385966