Yep.
I had a co-worker who was deathly allergic to peanuts. I sat two offices down from him, and was eating a PB&J for lunch. He stopped by my office on his way out the door, and was obviously in quite a bit of respiratory distress. He quickly explained the situation, and I never brought PB&J into that workplace again. No problem.
However - if I was THAT desperately allergic to things (like your relative with the shellfish allergy), I'd not eat out. Not worth risking my life over.
I get a feeling that some of it is "Hey, lookit me" -ism. I've got a co-worker like that. She's "Got a Gluten allergy", yet she has no fear of hitting the cookie / donut tray at work .... but in a restaurant, she'll quiz the poor waiter about every ingredient that might or might not be in the kitchen.
And you're right. Pork Allergy? Neeeever heard of it.
I don't know about a pork allergy, but I knew someone who was allergic to chicken. If she had a bite of chicken, her throat would swell and she might need a shot of epinephrine. Despite being the boss, she never ordered us not to have chicken in the office. She just avoided it whenever necessary.
No offense intended, but you got snowed! What you described has no medical basis whatsoever.
We had a ten year-old die in my county's school district. He ate a peanut-butter cookie he was given by another student and his throat swelled shut. The kid knew he was allergic to peanuts, but ate the cookie anyway. He had no epi-pen, and the EMS didn't manage to get there in time. Very sad situation. In response, the district brought in a specialist (M.D. with specialization in allergic reactions) and added epi-pens to all of the clinics.
The reason I tell you this is I heard this doctor (who knew what she was talking about) assert conclusively that there are NO food allergies that are dangerous based on proximity or non-contact exposure. PERIOD. Even the most allergic kid must EAT the food (though they can develop a skin rash from handling the food) in order to be at risk. She stated this as a medical fact (and the discussion was centered around peanut allergies, as this is what the kid had died from).
So your co-worker was a drama-queen, because the simple presence of peanuts (especially airborne) could not have possibly done anything to him, unless he ate some of it. He was just trolling for attention...