Lichen planus is an inflammatory disease of unknown cause that typically affects middle aged adults and can involve not only the skin, but occasionally the mucous membranes of the mouth and genitalia, scalp and nails.
It may be an autoimmune disorder with variable triggers such as medications or infections, in genetically susceptible people. Skin lesions usually appear as reddish-purple, flat-topped bumps that may be very itchy and commonly noted first on the wrists and ankles. Lesions in the mouth or on the genitalia can present with sores and painful ulcers and typically have an associated white lacy appearance to the surrounding mucosa.
Fortunately, most cases resolve on their own; but there can be recurrences and persistence of the disease in some for several years. Seeing a board-certified Dermatologist is important to accurately diagnose the condition, investigate any contributing factors such as infection or medication, and develop a treatment plan to control the symptoms and help clear the lesions.