Mine is definitely not a latex thing...I wear the same shorts under my leggings in the winter and never get any rash. I also did a century in August where the sun never came out and temps remained below 90 the whole way. 102 miles and no rash. They are mostly on the skin that is not actually under the shorts unless I wear my super long shorts and then they still show up in the same place, but now they are under the fabric and above the gripper! Plus, I used to wear latex gloves daily and never had any reaction (though I have no idea if they were chemically the same compound or anything).

Aicabsolut - Yours sound exactly like mine....they get dark when the swelling goes away. That's really interesting about the benadryl cream. I'll have to try that! Do you apply it after they appear, or before?