I have these red/purple blotches all over my body in a giraffe skin type pattern. They don't iche but looks very bad and people stare. My dermotologist does not know what to do so I am looking for answers! Please help!

I have something similar, or even the same. Purple blotches on my legs, butt and parts of my back. When I'm exposed to heat they go really really red and look horrible. Ive been to many doctors and none have any idea of what it is :(