Body itch when I feel hot

Does your skin have any (even very faint) discoloration in the most itchy spots? Might be http://en.wikipedia.org/wiki/Tinea_versicolor.

^^^ Oops, link maybe NSFW due to medical photo of partially exposed chest.

I have something similar where my legs will itch excrutiatingly if I walk for a long time. The skin also flushes quite a bit, uniformly, not in spots. It is exacerbated by cold weather and by clothing rubbing against my skin. A doctor once told me it was a histamine reaction in the skin, not harmful, just uncomfortable. I find if I take an antihistamine a little while before, it takes care of a lot of the problem.

I had cholinergic urticaria. Boy, did that blow. I'm not sure that's what you have, because I believe cholinergic urticaria expresses itself whenever and however your body temperature rises. And since you're not getting the itchiness when you take a hot shower, I'd be suspect of a cholinergic urticaria diagnosis. I was finally cured by a doc who threw in the towel after three weeks of me not being able to leave the house during the day. He prescribed a two-week course of prednisone (corticosteroid) and that killed it off. The dirty secret among doctors is that half the time they really don't know why we get some of the weird things that we get, and they don't know how to cure it. So they just start prescribing stuff. Luckily, the prednisone worked for me. For years after, though, I would still get a bit itchy when exercising, or going outside on a really hot day. What has completely knocked the urticaria out of my system in the last couple of years, though, is a commitment to better living. I eat much more healthily, drink less, and exercise more. As a person who has gone through a trying period of trying to figure out what kind of weird auto-immune affliction is shutting my body down, I feel for you. It's really distressing to have your body freak out on you and not know why. Lowering stress, eating well (whole foods, veggies, etc.), and exercising helped clear up my hives. So do that. But also go see a doctor.

Are you drinking enough water? As a teenager, I never drank enough (just subsisted on crap like soda), and when I'd exercise, it would really itch when I started to sweat. That doesn't happen to me anymore, since I keep myself reasonably hydrated.

So, I have a very similar problem to you, where the skin on my face would itch whenever I sweat during exercise. I assumed it was some bizarre allergic reaction and wiped my face with a paper towel when it became too unbearable. Recently, a lot of my allergies have gone away - including this one; I'm not sure how relevant my example will be but here you go. In my case I think I have a minor wheat allergy that was acting as a catalyst to all of my other allergies. I quit eating it and all of a sudden I lost my allergic reaction to sweat, uncooked fruits and vegetables, nuts, and my seasonal allergies. Then again it could just be Cholinergic Uticaria

I have a similar problem that is currently driving me nuts, as it has been over 30-35 degrees Celsius this entire summer where I live. This will sound kind of odd, but what's worked for me is that I eat a lot of "cooling foods" after I am overheated. This is a tenet of TCM, that your body can have too much heat or too much moisture. At any rate, I've been trying not to eat too many heating foods and more of the cooling ones. Keep in mind that this has nothing to do with whether or not the foods themselves are hot or cold, the other day I had a hot winter melon soup with cilantro. There is an http://albanacupuncture.com/blog/2009/05/26/chinese-medicinal-recipies-for-summer/ that goes into this.

my friend mark and i have been running together around fitzroy (in melbourne) oval lately, and he asked me if i itched when i started to sweat. I noticed that that i do, just as the sweat starts to appear, but it disappears soon after. In my case its not a problem, just a mild curiosity. I've been asking people and it seems a lot of people experience a mild itching when they start to sweat.

Hmm.. i am not sure, I don't have any discoloration or rashes. Its just itchy. Probably its dry skin. I'll try to have not that hot showers and use mosturizers and drink water. I'll see how it goes then. The itchyness is really sucky ! =(