Term: anaphylaxis: hypersensitivity reaction to the ingestion or injection of a substance (a protein or drug) resulting from prior contact with a substance
Broader: hypersensitivity reaction: an inappropriate and excessive reaction to an allergen (as pollen or dust or animal hair or certain foods); severity ranges from mild allergy to severe systemic reactions leading to anaphylactic shock | Unrelated: pain: emotional distress; a fundamental feeling that people try to avoid