Age 33, male, sit at computer all day for work.  On my left hand, one at a time, the skin on the backside of my knuckles (ring, middle, now pinky) have become hard, dry, itchy, and enlarged.  After about 10 days the thik skin begins to peel and I rip it away.  It remains dry and cracked for another week while healing. Possibly related: I was wearing a tungsten ring that probably had nickel in it; I was alergic to that ring (Im guessing the nickel).  It effected the front of my ring finger and a little on my middle finger.  I stopped wearing that ring a few weaks ago, about a week before my 3rd finger became infected.  The infection on the front of my fingers from the ring doesnt resemble to knuckle infection at all.
Hi try this simple treatment. Get potassium permanganate crystals. Take a bowl of Luke warm water and put a few crystals, enough to give medium pink color. Dip your left hand in it for 10 minutes, remove, Chat Doctor. . It should clear up soon. Regards