I have been getting a rash off and on since winter came. The rash lasts a few minutes but it is extremely itch and prickly. When i go out in the cold and return into a room that is warm/well heated my skin breaks out in a rash. The dermatologist said it might be some type of allergy. He has prescribed numerous medications and i am still getting the rash. I'm starting to worry it might be a symptom for something serious. I have been looking online for answers and have seen posts suggesting cancer all the way to hiv. Any suggestions? Am i over reacting?