I just got a nerve conduction study done for exactly that sort of tingling, except mine went/still goes down into that side of my palm. The verdict was ulnar nerve impingement. I was told to get the @#%$*!! off my elbow and side of my hand.

Does your chair have armrests? Are you resting the elbow/ulnar nerve on them? That could be a part of the problem. The doc talked about what he called "architect's hand" (or something similar - don't look it up, I think it's his own private terminology), where people, like architects have this problem 'cause they rest the sides of their hands on a hard surface to draw in all those lovely little bricks in their fancy drawings.

My chair at work is now without armrests, and I am typing right now with an elbow pad between me and the armrest on my chair at home. It's taken a month or so, but most of the tingling has gone away.

The doc told me to take a long rest under a tropical palm tree somewhere and the problem would go away on its own. I laughed in his face 'cause he forgot to say that he'd pay for it.

BTW, the nerve conduction study: If you have access to an electric fence, just grab onto that - it will feel about the same - except it will be much cheaper.