Hi, this could be tenosynovitis which is inflammation of sheath that surrounds the tendon. Do you have history of injury? Try anti inflammatory drugs along with antibiotics for 5 days and in case no relief is seen, do consult doctor. Better use crepe bandage for immobility.
For more information visit http://www.emedicine.com/emerg/topic571.htm
I had this! My orthopedic doc showed me that I was holding my pens too tightly. I teach writing and had a death-grip on the pens I was using to correct papers. He suggested I switch to fat pens and pens with soft wraps. I did and the pain/swelling disappeared over a short time.
Now, I'm very aware of how I'm holding my pens.
Good luck!
I had a ganglion cyst when I was younger. I don't remember any injury that could have caused it, just extremely painful. Started as a small swollen lump and eventually got so bad I couldn't close my fist. My doctor refused to treat for a long time said it was mild arthritis (I was 12!). I finally got it surgically removed when I was 15. No pain since.