Metal patch test on oral lichen planus and a history of hepatitis C virus infection

Dear Editor, Oral lichen planus (OLP) is a chronic inflammatory disease affecting the oral mucosa.1 Its etiology remains elusive; however, some trigger factors, including viral or metals, have been suggested.2 We examined 51 patients who were diagnosed with OLP by biopsy in the Department of Oral and Maxillofacial Surgery, Okayama University Hospital, between 2013 and 2017, and referred to our department to undergo a patch test (PT) on metals....