Hi there, This rash looks like a vasculitis. It is hard to diagnose something like this over the internet but I have had vasculitis a few times and it looked the same.Vasculitis is an inflammation of the blood vessels.
It can be caused by problems in the immune system, sometimes by medications, allergies and infection. I seemed to get mine when my oedema was at it's worst.
In this form I needed no treatment but if you get a fever etc, then you need to seek medical help.
Take care