Underarm Itching!! Red bumps....?

Ok, I have had these red bumps under one arm inparticular. The other comes and goes with itching. I have done everything, from switching laundry soaps, bath soaps, even switching deoderants, to even going without deoderants. (yeah I know, gross, but I'm desperate!) I have even put on hydrocortisone cream 1%. Even taken benadryl, which seems to help it SOME. I do take a hormone pill, estradiol .5 mg, as I've had a hysterectomy. I've done lots of search, but come up with nothing about hormone related itching,,,,I seem to itch all over my body, CRAZY INSANE itching with no other bumps, just under my arm,,,,the all over itching comes and goes,,,but this underarm thing is ALL THE TIME!!! This has gone on a year and I'm soooo tired of it! any advice? (I have an appointment in August to see my gyno,,that is the quickest they can get me in...) Thanks!!!