Oral lichenoid contact lesions related to dental metal allergy may resolve after allergen removal

BACKGROUND/ PURPOSE: Distinguishing oral lichenoid contact lesions (OLCLs) from oral lichen planus (OLP) is challenging. This study aimed to identify clinicopathological findings to distinguish OLCLs from OLP, and to evaluate the effectiveness of removing metal allergens in the treatment of OLCLs. MATERIALS AND METHODS: This study retrospectively evaluated 30 patients diagnosed with OLCLs, and 30 age- and sex-matched OLP patients. We also evaluated the effectiveness of removing dental metal containing positive metal allergen, confirmed by skin patch test and metal component analysis in patients with OLCLs. RESULTS: Palladium and gold were the most common patch test-positive metals observed in the oral cavity of patients with OLCLs. The patients with OLCLs were more likely to present with white type lesions in the buccal mucosa and gingiva than were the patients with OLP (p = 0.030, 0.009, respectively). Overall, 50.0% of patients with OLCLs failed to meet the histopathological diagnostic criteria of OLP. Twenty-three of 24 (95.8%) patients with OLCLs showed a complete or partial improvement after the removal of dental metal. CONCLUSION: The present findings suggest the importance of a skin patch test and metal component analysis to confirm suspected OLCLs related to dental metal allergy, as these lesions may improve with the removal of the allergy-inducing metal.