Thyroid Disease and Oral Lichen Planus as Comorbidity: A Prospective Case-Control Study.

Background: Thyroid disease has been mentioned to have a possible relation to the development of oral lichen planus (OLP).

Objective: Because goiter is considered endemic in many countries, we proposed to determine whether thyroid disease constitutes a comorbidity of OLP.

Methods: Two hundred and fifteen patients diagnosed as having OLP were evaluated concerning their serum thyroid-stimulating hormone and thyroxine (T4) levels. The results were contrasted with those obtained in control series of the same number of subjects matched for age and sex.

Results: Diagnosis of thyroid disease was present in 15.3% of OLP patients (33/215) and in 5.2% (12/215) of the control group. In relation to OLP patients, the odds ratio of presence of thyroid disorders was 3.06 and that of using levothyroxine medication 3.21.

Conclusions: In the present study, OLP patients were associated with thyroid disease, specifically with hypothyroidism. Because most thyroid patients need T4 treatment, our findings confirmed that OLP and thyroid disease could be comorbidities.