DUDE! I have the same exact frikken problem going on! It's what has led to me crazy gluing my fingers before every gig now, which by the way I believe might be exacerbating the problem.
The thumb on my left hand keeps cracking open, and it gets annoyingly painful. I have to treat the 2 playing fingers on my right hand with great care.
What I'm doing currently is using eucharin, wearing rubber gloves anytime I wash any dishes, and I have 2 creams that dermatologists gave me last year. One is a steroid, the other and antibiotic - I'm not crazy about using either, and they're not really helping anyhow.
I plan to read this thread, but if anyone has come up with any sure first solution I'd appreciate if I was led to the post number

. Otherwise I'm here to work this out with anyone else who's suffering from the same crap. It's not fun, and when my right hand cracks open it's downright painful (and I believe dangerous) for playing.