Hi there,
If it is JUST on your forearms from about wrist to just above the elbow, it could be Brachioradial Pruritus. There's many different reasons arms itch uncontrollably, but many cases of BRP is caused by cervical damage of some kind. I am also a sufferer for about 9 years. I do have a severe disc herniation at C5-C6 compressing the spinal cord centrally. I'll explain a little of how this happens, most people with herniated discs feel pain, tingling, numbness, weakness etc.