What is the definition of ecchymosis?

Ecchymosis is defined as an area of ruptured blood vessels that leads to discoloration of the skin, typically appearing as a bruise. It occurs when blood leaks out of the vessels and accumulates underneath the skin, resulting in a visible mark that can change color over time as it heals. This directly relates to the notion of a contusion, as both involve the leakage of blood due to vessel damage, albeit ecchymosis specifically refers to this phenomenon occurring in larger areas than a typical bruise.

The other options presented do not align with the definition of ecchymosis. For instance, a small hole in the skin does not reflect the nature of blood vessel rupture but rather indicates an injury or laceration. A round, localized area of edema on the skin suggests swelling, which is distinct from the discoloration seen in ecchymosis. Similarly, a fluid-filled blister describes a different kind of skin lesion entirely, often caused by friction or burns, rather than internal bleeding from ruptured vessels. Understanding ecchymosis and its characteristics can help in recognizing various forms of skin presentations in medical practice.