My Dad

My Dad is 78, and is in good health except for a progressive tingling/burning that started in his feet in July 07 and has progressed steadily into the back of his hands and up his arms and legs.  It can occur all over on one day and just be in spots on the next day.  In July, the sensation didn't begin until the early afternoon but now it's present almost immediately when he gets up in the morning.  The sensation lasts all day, but he takes a sleeping pill so he is able to get some rest.  He is also experiencing hot flashes at a higher rate as time goes by (2-3 per day, but no fever).  Blood work is OK (thyroid, B12, no diabetes, adrenal gland OK, etc.).  Neurology is also negative.  He's not taking any medication except for the sleeping pill (temazepam 30mg.....itching not listed as a side effect) and mirlax every other day.  Whatever this is, it is also not topical.......anti-itch meds have no affect.  This has become extremely frustrating.....does anyone have any ideas?  Thanks very much.