Lichen planus is a chronic mucocutaneous disease that affects the skin, tongue, and oral mucosa. The disease presents itself in the form of papules,[1] lesions, or rashes. Lichen planus does not involve lichens, the fungus/algae symbionts that often grow on tree trunks; the name refers to the dry and undulating, “lichen-like” appearance of affected skin. It is sometimes associated with certain medications and diseases, however the underlying pathology is currently unknown.