Lichen planus is a mucocutaneous disorder that can involve the skin, oral or genital mucosa, conjunctiva, and nails. On the skin, the disease presents as multiple papules, which can be localized or generalized, that are often extremely itchy. Mucosal disease can consist of either asymptomatic plaques or extremely painful erosive lesions. The disease course is unpredictable and typically lasts 1-2 years but can follow a chronic, relapsing course. Erosive mucosal disease is important to aggressively treat for many reasons: First, the associated pain can be debilitating for the patient. Patients with severe oral lichen planus can become malnourished due to pain associated with eating. Vulvar disease can cause dyspareunia, burning pain, and discharge; second, the disease tends to be chronic, with little chance for self-resolution; third, erosive disease is associated with an increased risk of squamous cell carcinoma in the affected areas. These cancers occur in up to 1% of patients over a 3-year period, and they can be aggressive and even-life threatening for the patient if not recognized and treated early.