Itching all over

I have had for several months a under the skin rash only on both sides of my back and it did not itch at all.  The doctors said they had never seen anything like that before and was unsure just what it was.  Not really defined bumps but more "mottled" like skin if thats the correct spelling of what they said.  Now though yesterday I began itching in different areas, around back of neck into hair line only in the back, on lower stomach, on sides no rash at all. just this extreme itchy feeling.
Have not changed bath soap, but for neck I had put on a gold chain and I stopped wearing that for I had reactions to gold a long time ago, other than that I am at a point what to try next.   Any idea what could be going on?  oh and no new medicines either.