What Causes Rashes All Over The Body?

I've been treating an itchy rash for a while - first, medrol, then diflucan and hydrocortisone, then clobetasol, and when that wasn't doing diddly, my doctor threw at it: kenalog lotion, doxepin, tagamet, more zyrtec (I had been taking one a day before that), and singulair. The itching is less intense (I was really bad), and the rash is calming down, though not completely. That same time, a week ago, he drew blood for a couple allergy panels. I haven't heard back on those yet. But today, when I was taking care of my skin (first kenalog, then moisturizer), I noticed a red (not pink) line along my bikini line, very different (and different direction) than my stretch marks. Is this something I should be concerned about?