What is the main characteristic of a venous ulcer?

A venous ulcer is primarily characterized by its irregular and shallow appearance. These ulcers typically arise as a consequence of venous insufficiency, where venous blood fails to return adequately to the heart, leading to increased pressure in the veins. This increased pressure can cause damage to the surrounding skin and tissues, resulting in an ulcer that appears irregular in shape and generally has a shallow depth. The edges of venous ulcers are often not well-defined, contributing to their irregular characteristic.

In contrast, deep ulcers with necrotic tissue are more commonly associated with arterial ulcers, which typically present differently due to factors related to ischemia. Well-defined borders and a lack of pain are characteristic of certain types of ulcers, such as pressure ulcers, rather than venous ulcers. Lastly, dry ulcers with scab formation might suggest a lack of adequate moisture and healing, which is not typical for the moist environment usually seen in venous ulcers. Thus, the irregular and shallow appearance of venous ulcers is a key feature that helps differentiate them from other types of ulcers.