For managing anxiety particularly related to anaphylaxis risks:
a) reassure the child that s/he is NOT solely responsible for life-saving medications and their use.
Sometimes these kids can get the idea that we as their parents and they as little children are the only people who really "get" the danger, and conclude that anytime you aren't in charge of them, they are on their own for basic safety. (While this has grains of truth in it, it's not completely accurate, either-- other adults CAN be trained to administer medications, recognize an emergency, and call for emergency medical aid, right?) You can offer reassurances that the babysitter, teacher, coach, etc. knows about the allergy/condition, knows how to get help, etc.
b) differentiate between the CHILD's responsibilities and those of the ADULTS in the child's life.
This is really hard for HG+ kids with this problem-- because they read so early, you have to make it very clear that food safety/risk management still isn't 100% on them, no matter that it theoretically could be... because (as we their parents know) they don't yet have the life experience and judgment to parse all of the information yet. My daughter CARRIED her own medications from a VERY young age, but she was very definitely not responsible for self-administering it. She never worried about that, but kids who start self-carrying between 5 and 10 yo may get this idea, and translate it into a fear of dying. HG+ kids with celiac, TypeI diabetes, or RA can also have some of these same concerns. But we can help them to understand that they really aren't expected to undertake complete management at these young ages. It's hard, though, because they ARE managing elements of them, and those elements ARE pretty critical, and they are very definitely not chronologically "age-appropriate" when viewed through a developmental lens.
HTH.
I'd ask questions to figure out "why" this is such a concern recently-- that will let you know where to go with it. The fact that it has been going on so long indicates (to me, anyway) that something there needs addressing, not just waiting out.
