hello, firstly i cant figure out any reason for the post traumatic swelling persisting even after one long year, there must be some other reason for this swelling. so i would like you to consult your pediatrician
who will be in a better position to assess the nature of swelling that your child is having post trauma. as far as the present swelling is concerned, if nothing is unusual, it should subside within few weeks. and if not serious the child may not need anything any medication other than simple pain killers. thanks.