How To Get Rid Of Bruise With Yellowish Tint On Shin?

Hi there. I have a spot on my left shin. It showed up a long time ago - maybe January or February. At first it looked kind of like a rash - a bunch of small red dots, but it didn't itch and they weren't bumps. It hasn't really spread much in the last 4 months or so - it's maybe half an inch bigger than it was at the beginning but now it looks kind of like a bruise with a yellow-ish tint behind it (but you can still see red dots when you look close). What is it and how do I get it to go away?