What Causes Reddish Discoloration On The Hand?

About 2 weeks ago I got a slightly reddish discoloration on the hand betweent he pointer finger and the themb. it is crescent shaped and a little over an inch long. It doesn't hurt or itch. it almost looks as if I was bitten by someone with my thumb and forefinger on either side of their mouth. I'm hesitant to go to the doctor since it doesn't hurt.