Pyoderma gangrenosum is an autoimmune condition that causes ulcers on the skin. The more common form affects the legs, but is usually more serious than the uncommon form which affects smaller areas on other parts of the body. Although poorly understood, pyoderma gangrenosum is associated with another autoimmune condition in about half of patients. Treatment is with steroids taken internally and applied topically to the affected area.In addition, treatment with antiseptics can prevent secondary infections. Grafts are not recommended at the condition usually affects the graft as well.