itchy skin and tiny bumps

ok, I'm quite puzzled.  I am 4 weeks post op.  For the past week my abdomen, back and arms have been itching like crazy.  It wakes me up at night!  This morning I woke up and I have teeny tiny red bumps scattered here and there.  What the heck is it?  I 've had a yeast rash before and its not like that at all.  In fact when the itching started there was no rash.  I asked the doc. yesterday and she said she's not heard of itchy skin with no rash.  Any idea.  I've tried Benedryl.  No help.  Grrrr

Seems to be a ketosis side effect.  Happened a lot to me on the journey down, but it faded out as my weight got closer to the end and progress slowed down.