I had the same thing- stenosing tenosynovitis, but in my third finger. It was probably caused by a sudden addiction to rock climbing when I started college- I get pretty gung-ho about new sports! I tried the cortisone injection and that helped for about a year, but it returned with a vengeance along with a weakened tendon. This required surgery to fix, and it's now been three years with no real problems beyond a lot of scar tissue. My advice- try to reduce stress on that finger and watch it pretty carefully -you don't want too many cortisone shots!