Women with Hashimoto's Thyroiditis Face Increased Risk of Oral Lichen Planus: Study Finds

"Those with both HT and OLP exhibited a greater prevalence of thyroid nodules (40.7% vs. 5.3%) and positive thyroglobulin antibodies (79.9% vs. 53.9%) compared to HT patients without OLP. Notably, this association was observed exclusively in female patients," the researchers reported in BMC Oral Health.

OLP, a chronic inflammatory disorder affecting the oral mucosa, has been linked to various systemic diseases, including thyroid disorders. However, the extent of its connection with HT remains unclear. Considering this, Yang Liu, Nanjing Medical University, Wuxi People’s Hospital, Wuxi, Jiangsu, China, and colleagues investigated the potential association between oral lichen planus and Hashimoto’s thyroiditis, highlighting key laboratory indicators that may contribute to the coexistence of these conditions.

The case-control study included 135 patients diagnosed with HT, of whom 59 had OLP, while 76 had HT without OLP. Researchers analyzed five key thyroid-related serum indicators—thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb), thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4)—to determine any significant differences between the two groups.

The study revealed the following findings:

• Patients with both Hashimoto’s thyroiditis (HT) and oral lichen planus (OLP) showed a higher prevalence of female predominance, thyroid nodules, positive thyroglobulin antibodies (TGAb), and an increased FT3/FT4 ratio compared to those with HT alone.
• The presence of thyroid nodules was significantly associated with an increased risk of OLP in HT patients (OR: 10.328).
• Positive TGAb levels were also linked to a higher likelihood of OLP occurrence in HT patients (OR: 6.936).
• A higher FT3/FT4 ratio was significantly associated with OLP development in HT patients (OR: 2.577).
• These associations were observed specifically in female patients (105 cases), while no significant correlation was found among male patients (30 cases).

Researchers emphasized that the findings underscore the importance of oral health monitoring in female patients diagnosed with HT, particularly those presenting with thyroid nodules and elevated thyroid antibody levels. Given the chronic nature of HT and OLP, early identification of risk factors may aid in better disease management and timely intervention.

The study contributes valuable insights into the interplay between autoimmune thyroid disorders and inflammatory oral conditions. Although the findings highlight a strong correlation, researchers caution that high variability among study participants necessitates further investigation to establish causality. Future studies should focus on exploring demographic and clinical factors influencing the relationship between OLP and HT to optimize patient care.

"Overall, this research highlights the need for heightened awareness among healthcare providers regarding the potential oral manifestations of HT. Patients, particularly women diagnosed with HT, should be encouraged to undergo regular oral mucosal examinations to facilitate early detection and management of OLP," the authors concluded.

Reference:

Liu, Y., Tang, Y., Zhou, Z. et al. Laboratory investigation of the association between oral lichen planus and Hashimoto’s thyroiditis. BMC Oral Health 25, 429 (2025). https://doi.org/10.1186/s12903-025-05780-2