Itching

I tchy arms are driving me nuts !I have been to dermatologist who prescribed 3 lots of cream in bulk, but that gives me little relief. I seem to have lumps under the skin,but apart from that not much to see. My arms ban bleed for no reason, even without scratching. I am at my wits end with this, and nobudy I speak to have experienced it, does anyone understand what I am talking about ?