Lichen sclerosus is a skin disorder that can affect men, women, or children, but is most common in women. It usually occurs on the vulva (the outer genitalia or sex organ) in women, but sometimes develops on the head of the penis in men. Occasionally, lichen sclerosus is seen on other parts of the body, especially the upper body, breasts, and upper arms. Other names for lichen sclerosus include kraurosis vulvae and hypoplastic dystrophy. Doctors think a too active immune system and hormone problems may play a role in the cause of lichen sclerosus. It is also thought that people inherit the likelihood of getting the disease. Sometimes, lichen sclerosus appears on skin that has been damaged or scarred from some other previous injury. Early in the disease, small white spots appear on the skin. The spots are usually shiny and smooth. Later, the spots grow into bigger patches. The skin on the patches becomes thin and crinkled. Then the skin tears easily, and bright red or purple bruises are common. Sometimes, the skin becomes scarred. If the disease is a mild case, there may be no symptoms.