My son has a severe peanut allergy and is a senior in college now. He’s been carrying his own Epipen since he little and now it’s just like having his keys, wallet or phone (and has another one in his backpack, his car and at his girlfriend’s apt.). The only times he’s ever been questioned about it were when he was studying abroad and going to bars that patted him down (I didn’t want to know why he went to bars that patted him down…). He learned to say “It’s medicine for my peanut allergy” in several different languages.
Start teaching your kid now. He’s going to have to learn to take charge of it.