I had petechiae on my shin once, and it looked really bad. I had hit the side of a concrete step with my leg while carrying a big box of Christmas decorations to the house. Since I couldn’t see where I was going, I hadn’t even slowed down near the steps, so I rammed into them hard.
I got a big bruise, but it started out as tiny purple dots. Once the bruise formed, it was still surrounded by dots. I knew that I had damaged my veins, because I had seen this type of bleeding under my mother’s skin when she injured her arm.