A skin ulcer is a crater-like formation on the skin that is caused by any number of reasons, from an infection to cancer or inflammation, report doctors at the National Institutes of Health. Ulcers are sores that typically do not heal properly or keep returning. Ulcers may or may not cause pain. Many people with skin ulcers experience a burning or itching around the area of the wound as well as discomfort from the swelling that usually accompanies an ulcer. Ulcers also may be accompanied by a red rash, a brown discoloration around the sore and dry, flaky skin.
When fluid builds up under the skin, it can cause a condition called stasis dermatitis that is characterized by skin ulcers. As fluid builds up in the body, blood cells are blocked from feeding the cells and eliminating waste from the system. As a result, the skin tissue becomes weak and improperly nourished. Ulcers on the ankles are most common with this condition because there is insufficient supportive tissue on the ankles and gravity is pulling the fluid downward. The swelling and fluid buildup also can be caused by poor circulation due to a number of other disorders, such as varicose veins or congestive heart failure.
Ulcers are commonly seen in people with diabetes, renal failure, hypertension and lupus, diseases that impair circulation and improper healing following accidents or trauma to the skin. Infections often turn into skin ulcers in people who have high cholesterol, high blood pressure, bowel disorders and sickle cell anemia. Disorders that affect blood clotting, such as arteriolosclerosis, can cause skin ulcers.
Tumors can cause skin ulcers. According to researchers at Merck, malignant skin ulcers caused by tumors account for nearly one million cancer cases every year in the United States. A biopsy of the skin lesion is required to diagnose cancer. Most lesions first appear on the head or neck, those areas of the body that have had the most exposure to harmful sun rays. Initially, it will have rolled edges and a pearly appearance, eventually developing into a crater-like ulcer.
Lying in one position can cause skin ulcers, most often seen in patients confined to bed. Also called bedsores or pressure sores, ulcers are caused by sustained pressure that cuts off the blood flow. The tissue becomes deprived of oxygen that results in the skin dying. While frequent shifting is required to prevent bedsores, often the friction caused by the movement exacerbates the ulcers, damaging the skin even more. Sliding on a bed or chair over time also can weaken the skin and cause open ulcers or bedsores, report doctors at the Mayo Clinic.