Lichen planus is an inflammatory condition that can affect the skin, hair, nails, and mucous membranes (such as the mouth and genital region). On the skin, it presents as small, pink to purple, itchy, flat-topped papules. Though the rash can appear anywhere (including on the genital skin), favored sites include the wrists, lower back, and ankles. In the mouth and genital region, the condition can present with erosions or ulcers (redness, rawness, and/or open sores). A characteristic finding is known as Wickham striae (white lines in a lacy like pattern) which can be seen both on the skin rash and in the mouth or genital region. Lichen planus can cause ridging, grooves, splitting, thinning, and/or scarring of the nails. It can also lead to tiny red bumps, scaling, and permanent hair loss on the scalp. Although the exact cause is unknown, it is postulated that the condition may be autoimmune in nature. No cure currently exists, but various therapies are available to treat the condition including both topical and oral medications.