What Causes Numbness In Arms And Itchiness On The Chest?

My arms seem to "fall asleep" often, mostly at night, but also seem to have an itchy skin issue to on my chest. The itching is so bad that is produces small bumps, which after scratching start to bleed. These symptoms come and go, but are always together. Any ideas? I had it when I was pregnant (I also had gestational diabetes). It is back again (I am not pregnant and there is no medical way that I can be).