What Causes Little Holes On Toes?

i have tiny little holes on my toes, they look quite deep and somepeople think its my shoes.. but i dont get how shoes can do this to my feet i also have a very big hole on the side of my foot its about 5mm.. not huge. and the outside of the hole is slightly raised.. and the hole its self is quite deep. its not tht i have old feet or anything.. im under 18! please help me out