About 9 years ago I developed an very , very itchy, small macular red rash in both my arm pits.Initially it was about 1" wide and 2" long. This became a rash that reoccurred every 4-6 months but each time it did the involved area was bigger. I have seen both dermatologists and allergists, have had skin scapings done etc and no one knows what it could be. At this point I still get it every 4-6 months andhave not been able to connect it with any change in soaps, detergents etc, I have it again now and it is about 8" long now from my arm pits down my side, and about 6 inches wide. each time I get it it gets bigger and the itch is always very very severe. I have had to take Prednisone in recent years over a week's taper to get rid of this rash. Any ideas??? I find it very frustrating that the specialists I've been to are clueless.