Hm. I wonder if this is what DD2 has on her hand?
She has a very small red mark, sometimes raised, inside a big blue/purple bruisey looking circle. Has been there since she was born, and sometimes the colour fades, but never permanently.
I have asked every doctor and nurse that has ever seen her what it is, but nobody has been able to tell me.

Some days it is more raised than others, but I suspect it isn't going anywhere.