I am having extreme pain at the base joint of my left ring finger. No notable difference with other digits. Stabbing, burning, severe pain. Thoughts?

Listen. Pain is telling you somethings not right, can't say without examining, would get it checked out if not improving.
Infection. 1. Could be infection is very painful and spreads quick in fingers - since it is ring finger could have started off as allergy to metals - pain will not be tolerable will require medical help 2. In holistic medicine sudden symptoms like these is a sign of acidic body causing oxidative stress. If this is the case use nac, lipoic acid, niacin, tryptophan and bromelain. Last 3 to relieve pain.