What is the primary cause of lower extremity ulcers?

Lower extremity ulcers are primarily caused by venous disease, which encompasses conditions such as chronic venous insufficiency. This occurs when the veins have difficulty returning blood to the heart, often leading to increased venous pressure and resulting in edema, skin changes, and ultimately ulcers, typically around the ankles or lower legs.

In cases of venous disease, the impaired blood flow causes blood to pool in the lower extremities, which can lead to skin breakdown and ulceration. These ulcers are often characterized by their irregular borders and a base that may be red and moist.

Other conditions, like diabetes mellitus, arterial insufficiency, and lymphatic insufficiency, can also contribute to lower extremity ulcers, but they tend to present differently and are less common as the primary cause compared to venous disease. For instance, diabetic ulcers often occur due to neuropathy and poor circulation, while ulcers due to arterial insufficiency typically appear as 'ischemic' ulcerations commonly located on the tips of the toes or areas of trauma. Lymphatic insufficiency can lead to ulcers, but this is usually secondary to severe swelling or skin changes that have developed over time.