Carbamazepine-Induced Oral Lichenoid Reaction: A Report of a Rare Case

Abstract

Lichenoid drug reactions (LDRs) are rare adverse effects that resemble lichen planus both clinically and histopathologically. Although cutaneous involvement is more common, oral manifestations are relatively uncommon. Carbamazepine, a widely used antiepileptic drug, has been associated with various cutaneous adverse reactions, but oral lichenoid reactions (OLRs) due to carbamazepine are rarely reported. In this case report, we present a 62-year-old male patient who developed painful white reticular plaques on the buccal mucosa and lateral borders of the tongue after using carbamazepine for approximately 14 months. The lesions completely regressed within three weeks following the discontinuation of the drug. No dental restorations or other possible local irritants were detected. Although histopathological confirmation could not be obtained due to the patient's refusal of a biopsy, the clinical appearance and full remission after drug cessation strongly supported the diagnosis. This case highlights the importance of considering drug-induced OLRs in the differential diagnosis of oral mucosal lesions, especially in patients using medications known to cause lichenoid eruptions. Early recognition and discontinuation of the offending drug are crucial for resolution and patient comfort.

Keywords: adverse drug reaction; buccal mucosa; carbamazepine; drug-induced lesions; oral lichenoid reaction.

Figure 1. White reticular and hyperkeratotic plaques with erythematous changes before drug discontinuation

Clinical presentation of oral lichenoid reaction induced by carbamazepine. (a) Reticular white plaques and erythematous areas on the buccal mucosa. (b, c) Hyperkeratotic white plaques and erythematous changes observed on the lateral borders of the tongue.

Figure 2. Mucosal healing following discontinuation of carbamazepine

Follow-up clinical images demonstrating regression of oral lichenoid lesions. (a) The dorsal surface of the tongue shows complete resolution of previous hyperkeratotic plaques. (b) The ventral surface of the tongue has regained normal mucosal texture. (c) The buccal mucosa appears normal with no visible reticular or erythematous changes.