Dermatitis / Eczema :: Red Itchy Rash That Travels Around

I am looking for help with my itchy red rash.  I posted under “Could this be scabies” a couple weeks ago.  I am at my wit’s end.  I went to urgent care about six weeks ago as I could not get in to see my doctor.  He never got out of his chair to look at it closely and told me it was dry skin and gave me a topical cream to put on it.   A week later I went to my doctor.  She looked at it closely and said it did not look like anything contagious and gave me prednisone for ten days.  Everything cleared up and I felt great.  At that time I had rashes under one breast, one on back at a hard to reach area and a couple on my  stomach line.  They all went away.  After being off prednisone for about a week they started coming back in other places.  I saw a dermatologist and he looked at me with a lighted magnifying glass.  He said it was dermatitis and prescribed betamethasone.  The cream makes the spots go away over a period of days and the itching stops or lets up.  But I keep getting new ones.  I now have spots along underwear line that looks like little bites here and there and some larger.  Also have a rash on the back of my neck that is just a lot of redness and itchiness with a couple bumps.  My skin is so sensitive to the touch in those areas.  Interesting thing is they are almost all on one side of my body and rarely go past the middle of the body no matter where they are.  They also bother me during the day when my clothes and seams rub them, but when I go home at night and relax and put sweat pants on and a t-shirt the itching will subside some.  I don’t have itching at night in bed but may wake up with a couple more spots.  My husband has not had any itching at all this whole time.  I have never had skin problems.  Does this sound like dermatitis?  I see the doctor in four weeks and he wants me to not use the cream on three areas so he can biopsy it to confirm dermatitis.