A leg ulcer is an open sore on the skin of the lower leg that does not heal readily, typically persisting for over two weeks. These wounds represent a breakdown in skin integrity, revealing underlying tissues. Unlike minor cuts or scrapes, leg ulcers are visible lesions indicating an ongoing issue affecting the skin’s ability to repair itself. They can appear in various sizes and shapes, signaling different underlying health conditions.
Defining Visual Features of a Leg Ulcer
Leg ulcers present with shared visual characteristics. An ulcer is an open area, often appearing as a crater-like depression on the skin. The depth of these sores can vary significantly, ranging from shallow breaks in the outermost skin layers to deep wounds that expose muscle, bone, or tendons.
The edges of a leg ulcer offer important visual clues. They might be irregular, undefined, or appear “punched-out” with sharp, distinct margins. Some ulcers develop raised or rolled edges, suggesting prolonged tissue damage.
The wound bed, or base, can display various colors depending on the tissue present. A red base indicates healthy, granulating tissue. Yellow tissue, known as slough, signifies dead or dying cells and can appear stringy or moist. A black base points to necrotic tissue (eschar), which is dead, hardened tissue. In some cases, the base may appear pale, indicating poor blood flow.
Leg ulcers frequently produce discharge. Serous discharge is a clear or yellowish fluid, indicating normal healing. Serosanguinous discharge is a pinkish fluid, a mixture of serous fluid and blood. Purulent discharge, which is thick and often yellow, green, or brown, signals a possible infection. An unpleasant odor can accompany purulent discharge.
Appearance of Common Leg Ulcer Types
The visual presentation of a leg ulcer often provides clues about its underlying cause.
Venous ulcers, the most frequent type, typically form on the inner part of the leg, just above the ankle (the “gaiter region”). These ulcers are usually shallow with irregular, uneven borders. The wound bed often appears red due to healthy granulation tissue and may produce moderate to heavy fluid, making the ulcer look wet or weeping.
Arterial ulcers, caused by poor blood flow, tend to appear on the toes, feet, heels, or other bony prominences. These ulcers have a “punched-out” appearance, characterized by round or symmetrical shapes with sharp, well-defined borders. The base of an arterial ulcer is commonly pale, yellow, or black due to a lack of oxygenated blood and dead tissue. They typically have minimal discharge, appearing dry. These ulcers are often quite painful, especially when the leg is elevated.
Neuropathic ulcers, commonly associated with diabetes, arise from nerve damage combined with pressure or injury. They are most frequently found on the soles of the feet, particularly on pressure points like the balls of the feet, heels, or under the toes. These ulcers can be deep and are often surrounded by a thick rim of callus, which can obscure the true size of the wound. While they may have a “punched-out” appearance, the distinguishing feature is often the presence of surrounding calloused skin.
Accompanying Skin Changes Around Leg Ulcers
Changes in the skin surrounding a leg ulcer offer additional visual cues about its nature.
With venous ulcers, the skin around the wound often shows discoloration, appearing reddish-brown or dark brown due to hemosiderin staining (iron pigment from blood pooling). The skin may also become hardened or thickened, a condition known as lipodermatosclerosis. Swelling, or edema, is common around venous ulcers and can make the skin appear shiny. Sometimes, flaky, scaly, and itchy skin, indicative of varicose eczema, is also present.
For arterial ulcers, the surrounding skin often appears pale, cool to the touch, and shiny. Hair loss on the affected leg is common, and the skin may also feel thin or dry. These changes are a direct result of poor blood circulation to the area.
Regardless of the ulcer type, certain visual changes in the surrounding skin indicate an infection. These signs include increased redness that spreads beyond the ulcer’s immediate border, noticeable warmth around the wound, and swelling. The discharge from an infected ulcer may become thicker, change color to green or yellow, and develop a foul odor.