Are you sure you don't have a plumbing leake?

In an older house we lived in, I got rid of all the loose paint, then used some plain white tileboard, gluing it into place with liquid nails. Never had a peeling problem after that! To repaint, I think you'd have to make sure your shower area is completely dry, and you might even have to strip the paint (if it's plaster). Then prime it with a good primer like Kilz (so your new paint sticks to the wall), and paint it. I've also heard that in rooms that are a bit damp, it's better to apply a paint that has more gloss to it, or get a paint made specifically for bathrooms. (It must evaporate the water quicker.)

-= N =-