I've had this happen to me too, but I think it was more from what I do at work. I'm a printer and I handel a LOT of paper, we're talking an average of 30,000 sheets of paper every day. And it's not your usual "printer size" paper, it's usually about 25 inches by 35 inches.
Nonetheless, it really reminds me of shin splints only on your forearm. Think about it, same basic part of the limb, right against the bone. And very sharp. I find that if I get away from handling paper for a while or in your case preacher curls, the pain gradually goes away. But then comes right back when you go back at it.
Don't really know if there is any "cure" for this. If you find out anything please be sure to post it!!