Imagine an alien medical officers just asking about allergies.
A: So you mean to tell me that Human John almost die from ingesting a peanut? How? Peanuts taste great!
H:It’s cause our immune system.
A: The same thing that is actively protecting your body on that hostile environment you call a planet?
H: Yeah….sometimes our immune systems overreact to harmless things.
A: Okay, some humans can’t ingest peanuts. Anything else I need to know?
H: Well actually, some humans just can’t come into contact with peanuts. At all. Or fish. Or pollen. Or any type of nut. Some humans can’t drink milk or take in dairy. Some humans can’t have stuff touching their skins.
A: Again, HOW HAVE YOU SURVIVED? YOUR OWN BODIES ARE TRYING TO KILL YOU.
H: What doesn’t kill you makes you stronger.