Rash that won't stop itching ....

I haven't been around bugs my house is clean I don't have pets .....I got this rash right before I found out I was pregnant...I didn't have this with my first child( this is my second one also my last) I had a host of other problems with my first but any way ...this rash is like massive welts that itch like some one who's allergic to mosquitoes or something. At first it was a few then it'd go away but now I have them from my finger tips all the way up my arm and same on my left arm it's not poison oak or anything either it's caused by the histamine levels being to high in reaction to the baby I'm carrying like it's intrusive or something. ..

My point has any one had something like this or had pupps? If so what do you do to relieve it I've tried all the cremes none work I take zrtec and benadryl ( not ar the same time but yeah ) some one please help the itch is killing me