Maybe something simple like this one? I know it's kinda vampirey... but hey, my grandma has bite scars from working in a Psychiatric Ward many years ago.
Or... maybe... a cake covered in white fondant with words written on it like....
http://deadlyeverafter.files.wordpress.com/2013/03/you-cant-hide-lv.jpg
http://lovethesepicture.files.wordpress.com/2012/05/all-kinds-of-crazy-graffiti-at-abandoned-linda-vista-hospital-does-this-say-please-put-your-grandma-in-this-room.jpg?w=870
maybe something like that?
