I actually had the exact same red spots appear all over my body the past year. I've also had significant breathing trouble though and cold extremities, from what I read they can appear due to poor circulation and oxygenation of the body.
I've also been dealing with adrenal fatigue, put on by many factors, injury, severe allergies, toxicity. So I suppose it could be coming from many sources as well.
Good luck getting a useful answer from your doctor, please let us know what he/she has to say.