An arterial ulcer is a chronic wound that develops due to insufficient blood flow to the lower extremities, signaling a significant underlying circulatory problem. These wounds manifest when tissue cells cannot receive the oxygen and nutrients necessary for survival and repair. Recognizing them early is important because they signal advanced vascular disease, which carries serious consequences for the limb and the patient’s overall health. Without proper diagnosis and intervention to restore circulation, arterial ulcers often fail to heal and can lead to severe infection and limb loss.
Defining Arterial Ulcers
An arterial ulcer is a full-thickness skin breakdown resulting from inadequate arterial blood supply to the affected area, a condition known as ischemia. These ulcers are characterized by a distinctive, “punched-out” appearance with well-defined, regular edges and a round shape. They are often deep, sometimes extending down to the underlying tendons or bone.
Common sites are the toes, the outer ankle bone (lateral malleolus), and areas subjected to pressure or trauma, such as the heel. The wound base is frequently pale, yellow, gray, or black due to tissue death (necrosis), and it produces minimal drainage because of the poor blood flow. Unlike other wounds, an arterial ulcer exhibits little to no signs of new, healthy tissue growth.
The Underlying Pathophysiology
The formation of an arterial ulcer is directly related to a restriction in the blood supply, which deprives the tissue of oxygen and nutrients. The underlying cause is overwhelmingly Peripheral Artery Disease (PAD), a condition where arteries outside the heart and brain narrow. The primary driver of PAD is atherosclerosis, commonly called “hardening of the arteries.”
Atherosclerosis involves the progressive build-up of fatty deposits, cholesterol, and plaque along the inner walls of the arteries. This plaque accumulation causes the arterial lumen to narrow and stiffen, significantly reducing the volume and pressure of blood reaching the lower limbs. When this reduced flow cannot meet the metabolic demands of the tissue, even at rest in severe cases, the tissue becomes ischemic.
This chronic lack of sufficient blood flow prevents the skin and underlying structures from repairing minor injuries, leading to tissue death and the formation of an open wound. Ischemia means that a minor scrape or cut, which would normally heal quickly, instead progresses into a non-healing, chronic ulcer. In very severe disease, tissue may die without any preceding injury, leading to gangrene.
Recognizing the Clinical Signs
Arterial ulcers are accompanied by a distinct set of symptoms related to poor circulation in the limb, beyond the wound appearance. A hallmark symptom is severe pain, often described as burning or cramping, which frequently worsens at night or when the leg is elevated. Patients may find temporary relief by dangling the affected foot over the edge of the bed, allowing gravity to assist blood flow.
The skin on the affected limb is often thin, shiny, and hairless due to chronic malnutrition. The limb feels cool or cold to the touch due to minimal blood circulation, and the pulse in the ankle or foot may be diminished or entirely absent. A noticeable color change, known as dependent rubor, occurs when the leg is lowered, causing it to turn dusky red, and then becoming pale when elevated.
Assessment and Comprehensive Management
The initial assessment involves confirming the diagnosis and determining the severity of the underlying Peripheral Artery Disease (PAD). Clinicians commonly use the Ankle-Brachial Index (ABI), a quick, non-invasive test that compares the blood pressure in the ankle to the arm. An ABI value below 0.9 suggests the presence of PAD, with values of 0.5 or lower indicating severe disease.
Further assessment may involve a Doppler ultrasound to visualize blood flow and identify the exact location and extent of arterial blockages. Management focuses on two distinct areas: restoring blood flow and providing local wound care. Restoring circulation, or revascularization, is the primary objective for healing and often involves procedures like angioplasty, which uses a balloon to open the narrowed artery, or bypass surgery, which reroutes blood flow around the blockage.
Local wound care involves protecting the ulcer, controlling infection, and managing pain. Dry, stable necrotic tissue (eschar) should often not be aggressively removed from an ischemic ulcer until blood flow has been restored, as this tissue acts as a natural biological barrier against infection. Infection control may require targeted antibiotic therapy, especially since infection in a poorly perfused limb can rapidly lead to deeper tissue damage and potential amputation.