As long as there isn't any change (i.e. passed challenge or miracle cure) once a kiddo has one it's difficult to get it taken away. What is within the doc can and will based on age/setting/ability.
) DH's office is down the hall from student services who put out a jar of PB as a 'welcome' for students and lots of lots of candy. I can't tell you how often they've tried to feed my little one.