One is an allergy hypersensitivity that triggers the release of histamine that (in this scenario) closes the throat and causes the person to die.
The other is a lack of an enzyme in the stomach to break down a specific component, so instead bacteria break it down. When they break it down, gas is released, which causes the stomach to be irritated.
So one is your throat literally trying to kill you, vs your stomach being irritated (possibly very bad). Not downplaying lactose intolerance, but its not the same as a type 1 hypersensitivity
Edit - as pointed out, most the stuff for lactose intolerance happens in the intestines not the stomach
This is the real difference.
One is an allergy hypersensitivity that triggers the release of histamine that (in this scenario) closes the throat and causes the person to die.
The other is a lack of an enzyme in the stomach to break down a specific component, so instead bacteria break it down. When they break it down, gas is released, which causes the stomach to be irritated.
So one is your throat literally trying to kill you, vs your stomach being irritated (possibly very bad). Not downplaying lactose intolerance, but its not the same as a type 1 hypersensitivity
Edit - as pointed out, most the stuff for lactose intolerance happens in the intestines not the stomach