MODEL RELEASED. Leg ulcer in venous stasis on the shin of an 87-year-old woman. An ulcer is an open sore on the skin, or a mucous membrane, that results in the destruction of the surface tissue. Ulcers are commonly found on the legs and feet, and are often due to an inadequate blood supply. Ulcers need to be kept clean and allowed to heal. Painkilling and anti-inflammatory drugs may also be given during treatment.