I use real butter with my meals almost daily. Whenever I get some on my hands I rub it in. Same thing with bacon grease or any animal fat. Rub it in. This and letting my dog lick my hands are the only things I've done different, and my fingertips haven't cracked for two seasons. I used to take Omega oil supplements. That did not prevent the occurence for me. Made me wonder why in the world plant oils would be a replacement for the animal (skin) oil we lose that results in dry skin. Too bad they don't have lotion made from human skin oil!
Prior to discovering this I tried all kinds of lotions, super glue, bandaids, and had pretty good luck getting them to heal and nipping them in the bud by cutting away the dried/dead edges with a nail clipper. Do this when the first sign of cracking appears, but careful, not too deep! Applying enough bandaid sheer strips with the gauze removed kept the area moist, so they wouldn't crack further, and helps hold the crack shut.
I am so thankful to be rid of this suffering! Hope I can help someone else!