im so happy i read this....ive had this happen for years and i never knew what it was. Im really fair skinned so it's pretty obvious at the gym. It only happens on my shoulders and legs..and usually when im doing something high intensity like step class.

When I read all of these post today Iwas amazed that other people have the same problem that I do. It always happens in the first few minutes when I begin to run, mostly on my legs but then spreads to my back, shoulders, neck, chest and everywhere. I have concluded over the ast 5 years of my life that it begins when my temperature changes qucikly. Just today I have discovered an actual suggested disease and cure for our symptoms. Another Dr. from a site suggests that when your skin heats up in some people in causes some kind of hives whcih itch. Its called cholinergic urlicaria. He suggests taking claritin or Allegra 30 minutes before your work out.