Hello, I get a slightly raised rash that is solid red/purple resembles a bruise or burn . It is on my buttocks , forehead, chin , upper lip , behind my knee, on my knee, and a small one on my back also a slight welting under my eyes (and cheek) and on my nose. It does itch and is very uncomfortable. They are about dime to quarter sized. In some places just one small circle, in others its a cluster of round burn like circles. Ive also noticed my tongue feels rough and the roof of my mouth feels swollen too. These rashes tend to leave a dark mark after theyre gone. What could this be?