What Could The Bruise Like Spots On Thighs Indicate?

I just noticed reddish bruise like spots on the backs of both of my thighs. They are up by the crease of my leg and buttocks. They are slighlty tender to the touch. I have also been more tired than usual, I am not sure if it is related in any way but I seem to get UTI frequently. Just got over one about 3 weeks ago???