Red skin, auto immune, skin or other

[Mean_Kitty]

I started having a red hot face over  year ago.  Nobody could figure it out,  Fionally I was told maybe Rosacea.  Now my arms, chest and back have a red hue to them and when I carry something on my arms even lightweight my skin reacts and turns bright red and blotchy.  Parts of my back look sun burned but I am never out in the sun.  My derm is stumped and my primary care ran a bunch of blood tests but I have no seen them yet.  What would cause this?  I am so tired of red irritated over sensitive skin.  

[Mean_Kitty]

and my skin drives me crazy a bit, like an underlying itch,  Antihistamines are not helping!!