I have a 5 year old who has never liked to get dirty. We first noticed on her first birthday - she made grandma feed her her birthday cupcake, after freaking out a little when the frosting got on her finger. Just today she played with play dough, but she never actually touched it. She flattened it on the table with a spoon and used a knife to create shapes out of it.
I guess I'm not sure if this is a passing phase since she is only 5. She does have rare moments of messiness - when she sees how much fun her messy brother is having with food coloring in the snow, for example. We don't really make a big deal of it.