What are common features of petechiae?

Petechiae are small, pinpoint hemorrhages that typically measure less than 2 millimeters in diameter. They result from the rupture of small blood vessels, leading to bleeding just under the skin's surface. The defining characteristic of petechiae is their size and appearance; they look like tiny red, purple, or brown spots, which is why option C accurately describes them.

In contrast, raised lesions indicate more significant structural changes in the skin, such as rashes or welts, which do not describe petechiae. Additionally, petechiae are not classified as very large; they are small by definition, so size differentiates them from larger types of hemorrhagic spots. Finally, petechiae are typically not painful, distinguishing them from other types of lesions or injuries that may cause discomfort. Thus, the defining feature that aligns with the established medical understanding of petechiae is that they appear as pinpoint hemorrhages.