My 86 year old mom has an itch on her back, down her spine, arms, neck for 4 months straight. She has no rash and hardly sleeps because she can t get relief. She s been to many doctors which still haven t been able to diagnose her or give her medication for relief. She s been to her medical doctor, dermatologist, allergist, and 2 heart doctors. I need advice on what type of doctor she should see now.