response: That's bad. Things like food and medications can cause severe reactions
original_response: Sorry to hear that. I've been told I'm allergic to penicillin. Allergies to medications can cause serious reactions.
history: I have really bad allergies. Oh, I'm sorry to hear that your immune system is hypersensitive to things that usually cause no problem for others. May I ask what you are allergic to? I am allergic to pollen and some dander. When it's pollen season my allergies go crazy.
knowledge: Food, insect stings, and medications are common causes of severe reactions.