Am I allergic to biking? Help!

[TsPoet]

It doesn't sound like EIA, but I thought I'd throw it out there. About 10% of the people who have Exercise Induced Allergy (or Asthma) get hives/rashes. I am part of that 10%.
My hives are all over, not just in one area, so I don't think that applies, but it's something to check out. I also only get the breathing problems when the temperature outside is either hotter or colder than what my body is used to that day.

[GLC1968]

Thanks for all the new suggestions!

I've done some reading and what I have are definitely hives but they are very localized. It starts only about 4 hours into the ride, so it's not just basic EIA. I also have no breathing problems...if anything, the longer I ride, the better my CV system seems to work.

Because this rash shows in the same spots when my shorts totally cover it, I don't think it's sun induced either.

I'm going to have to try the Monday appointment thing, but by the next day, the swelling has definitely gone down leaving only red marks. I think the combo of the red marks and a photo of the welts should provide enough information for a preliminary diagnoses...right?! Actually, what I should do is make an afternoon appointment, and then take the day off and ride that morning. Oooh...that might just be the answer! Now lets hope I don't have to wait until October to get a derm appointment!

If I learn anything terribly fascinating...I'll definitely share with you all.

[TriChickie]

GLC, I get exactly the same thing as you do. I've just been assuming it is heat rash. I'm a little interested in the PABA suggestion, as maybe a combo of heat and shorts rubbing on the sunscreen. I'd love to hear what your Derm Doc has to say!

[uk elephant]

I get the same thing. Red bumps/rash on the top of my thighs after a long hot day in the sun. Heat rash. As far as I know, it's just a reaction in the skin to being overheated. Not really something to worry about. It goes away by itself, doesn't hurt or itch so why put drugs on it? And I'd stay away from the cortisone creme. Steroids are not something you want to take any more than absolutely necessary. For me, all it takes is to try cooling off regularly throughout the day. And if I do get it, put a cold towel on when I get home to cool the skin down again. Then just let it clear up by itself. Usually it's gone in a day, two at the most if it's really bad.

[Aggie_Ama]

You have had a lot of good suggestions. Nanci threw out oatmeal baths. I cannot survive heat rash or exzcema flare ups without them. You can get a box of Aveno Oatmeal bath packets at the drug store. It really soothes irritated skin. Just be careful, it makes the tub slick. They also have a lotion that I use and love it! Plus it is fragrance free, so it doesn't cause additional problems.

I try to stay away from steroid/cortizone creams until my skin is at the worst point. I think you can build up a tolerance to these and they lose their power. There may be other reasons to only use them for a short period of time.

[GLC1968]

OK, I admit it...the main reason I want to see a doc is because it is UGLY! My legs are ugly enough as it is...I don't need nasty looking red marks calling attention to them! (and the option of long pants is not really an option in our heat) Plus, it's Wednesday and my legs are STILL splotchy and red, so even though it isn't painful/itchy, it still worries me.

I'm wondering if it may lead to something more. My skin looks kind of odd in those spots even when the rash goes away, so I don't want to be doing permanent damage if it can be avoided. Because it gets worse with each long ride it makes me feel that seeing a doctor would be prudent...medications or not.

[Righteousbabe]

I get the same rash. It is right at the shorts line on the tops of my legs. I only get it in the hotter summer months on my long rides. The last couple summers I just dealt with it. But this weekend my rash was worse than usual (huge, raised welts and tender to the touch). So I decided to see if I could get in to the dermatologist on Monday. He took a look at it and I described how it only happens during my long, hotter rides. That I have tried everything I could think of (different sunscreens, different laundry detergents, rolling the shorts up higher, etc) but I still get it on the same spots on the legs. He thought that it was the chemicals in some of the sunblocks, and suggested a titanium dioxide sunblock. I told him I have tried that already and it does not make a difference. He was stumped. So he just prescribed a strong steroid cream and said if it does not go away or gets worse, come back. If he has no idea what is causing it, I do not know why I should go back...

So...I have decided it is some type of heat/sun rash and I will just have to live with it. If anyone else goes to the doctor and actually finds out what it is and has any suggestions, please let me know!