Being the parent of an allergic kid is a fine and difficult line to walk. My friend's daughter is 11 and has been severely allergic to milk and wheat since birth. She has many allergies, but those are her main ones. I know it's real, because I've seen the kid go into anaphalaxis myself. There are many things she can't eat, but there are also many things she can eat. The problem is...she became so freaking afraid to eat that she barely eats was diagnosed as Failure-To-Thrive at age 5. Her mother is a nervous-panicky type, and I don't think that has helped. She's been treated by eating disorder clinics, because her FTT has now evolved into anorexia. She weighs about 50 pounds now, still severely underweight. She looks skeletal and weak and just very unhealthy. She's homeschooled, because of the allergies, and gets barely any exercise...she's just too tired all the time.
I don't really have any advice. I guess just try to be cautious without showing fear and teaching fear. Hopefully, she'll outgrow the worst of it.