My two year old step son came home from his mothers with a detached nail on his index finger, upon observation, I had noticed his thumb nail on the opposite hand was becoming detached at the base of the the finger. Both of his big toes are also detaching at the nail bed and there appears to be mild bruising along the cuticle, the shape similar to the white crescent shape on the bottom of your thumbnail. Is this caused from trauma to the nails that a highly active two year old would be subject to or is there reason to be concerned? There is redness on the index finger where the nail has completely detached and he complains of occasional discomfort, but no other redness or pain associated with any other nail.