Use of systemic medication in patients with oral lichen planus - a possible association with hypothyroidism

Several drugs have been regarded as a possible aetiological factor for oral lichen planus (OLP).

To investigate the medication profile of patients with OLP and its possible association with the pathogenesis of OLP.

Data from 956 patients with OLP and 1029 controls were collected using a standardized registration method. All regular medications were recorded and classified according to the Anatomical Therapeutic Chemical Classification System.

Patients with OLP used thyroid preparations (P < 0.001) and non-steroidal anti-inflammatory drugs (NSAIDs) (P < 0.01) in higher proportions compared to controls. A multivariate logistic regression model demonstrated that levothyroxine was associated with OLP (multivariate OR 3.39, 95% CI: 2.09-5.46, P < 0.001), even after controlling for confounders, including age, sex, smoking, allergies and systemic diseases. No statistical significance could be found between NSAIDs and OLP using the same model.

In this study, the use of levothyroxine was associated with OLP, which in turn suggests a possible connection with hypothyroidism.