What causes severe itching of the palm area only?

What causes severe itching of the palm area only? There is no rash, but the area will get dry and white after scrathing. I thought it was caused by allergies, but my allergist hadn't heard of this symptom on the palm only. It happened on the right palm only until I had carpal tunnel surgery. Then the left palm started itching - only the palm; no other area of the hand. I talked with someone who said her doctor told her this may be a symptom of carpal tunnel syndrome. My doctor never heard of that symptom. The itching is so bad sometimes I cannot stand it. It is not constant and will not happen all the time. It will usually bother me for a few days then go away, but will just start up again at another time and I'll go through the same thing.