I've noticed my skin prunes quicker than it used to. I suspect this is tied up with overall health but I've never heard anything specific about it. Perhaps I'm just imagining things.
Pruning of fingers and toes in water seems to be related to the differential of water retention between the dermis and epidermis. But why the increased susceptibility to pruning as one ages? It takes a very long time for my five-year-old to have his skin wrinkle in the bath. I suspect there's an overall health correlation, and I suspect that this correlation could be tied in with diet.