You're resting your elbow on a hard surface, which is very bad for your body! If you look up the correct typing position you will feel much better in time (although at first will feel unnatural & forced). It may seem odd to you, but a tendon running from your elbow is "in charge" of your pinky & ring finger, get rid of the pressure on your elbow & voil, no more pinky issues, yay! Hope you look up an image of how to sit correctly, otherwise in the near future you will suffer somewhere else, such as, upper back pain from lifting your elbows but not keeping your back straight. Good luck on your new pain-free typing! =)
This may be from to much typing and you are getting a strain in these fingers. Try elevating your palms with a small towel and see if this angle is a little easier for you. You may need to get a different keyboard that is better for your typing needs.