Conditions affecting the MOTOR (movement) neurons are more
immediately serious IMO than sensory.

Usually sensory neurons are affected first by most triggers. But autoimmune disease and things like GBS, affect motor neurons and one can lose mobility and maybe permanently.

Most toxins and poisons affect both feet and hands. If you only have hands affected, and this going on for years, then there is "something" causing this. Something mechanical most likely.

Many of the serious neuropathies are progressive, and the feet would be showing problems by now as you have had this for years.

Have you been evaluated for arthritis? Both OA and RA?
Do you have hard nodules showing up on your first finger joints?
http://www.webmd.com/arthritis/heber...ouchards-nodes
I have both of these types, on both hands, but they are not really large yet, except my right thumb. Sometimes they hurt and sometimes not. My magnesium lotion (Morton Epsom lotion) seems to keep them to a dull roar most of the time.
You can soak your hands in warm epsom salts in a tub and see if that helps. The magnesium works on pain receptors and gives some relief.

Do you have itching, or rashes?