In reply to CharlieMack:
Have exactly the same symptoms at the moment. Fairly sure it's a tendon tweak/microtear possibly. Am fingertaping while climbing and avoiding any problems that involve crimping on my left hand as I'm pretty sure that's what caused it in the first place. It does feel like it's getting better though. If your injury doesn't would suggest further rest, frequent icing (cold/not sugar) oral ibuprofen for a few days (with food) and hot and cold treatment (plenty of info within these forums) once the pain starts to subside a bit. Good luck with it.
Above all - don't do anything to make it worse would be the most important advice I could give. I had a bad one about 3 or 4 years ago and couldn't pull hard for about a year afterwards, so i would urge caution! Good luck with it...