Case Report:
Lichen planus is an inflammatory disorder of immune dysregulation that affects the skin and mucosa. Oral lichen planus (OLP) is a chronic variant characterized by white mucosal lesions,1 most commonly with bilateral buccal mucosa involvement and frequently involving the tongue and gingiva as well.2 Although the underlying cause remains obscure, OLP is thought to have an autoimmune etiology and has been linked with genetic factors, hypertension, diabetes mellitus, hepatitis C virus, and thyroid dysfunction.3
OLP onset involves the activation of immune pathways leading to migration and activation of T cells and the destruction of keratinocytes.4 It is thought that oral mucosal keratinocytes are activated by the expression of unknown antigens, which recruit lymphocytes. This T-cell-mediated response is coupled with the simultaneous nonspecific response of matrix metalloproteases, chemokines and mast cells, together causing apoptosis of the basal keratinocytes by various mechanisms.
OLP can undergo malignant transformation to oral squamous cell carcinoma (OSCC) in a small subset of OLP patients (1%), more commonly in smokers, alcoholics, and hepatitis C patients.5 It is thus considered an OSCC precursor lesion. Topical steroids are the first-line treatment, but systemic steroids and topical calcineurin inhibitors can be used to manage recalcitrant cases.6