dermatologic disorders
Lichen Planus
Key Points
Lichen planus (LP) is thought to be an autoimmune disorder in patients with a genetic predisposition but may be caused by medications or be associated with disorders such as hepatitis C. LP is characterized by recurrent, pruritic papules that are polygonal, flat-topped, and violaceous and can coalesce into plaques. Oral and genital lesions can develop, become chronic, and cause morbidity. Diagnose LP by clinical appearance and, if necessary, biopsy. Treat localized LP with topical or injected corticosteroids. Treat generalized LP with oral medications or phototherapy. 