Anaphylaxis and Hypersensitivity reaction

Anaphylaxis noun - Hypersensitivity reaction to the ingestion or injection of a substance (a protein or drug) resulting from prior contact with a substance.

Hypersensitivity reaction and anaphylaxis are semantically related. In some cases you can use "Hypersensitivity reaction" instead a noun "Anaphylaxis".

Hypersensitivity reaction noun - 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.

Anaphylaxis and hypersensitivity reaction are semantically related. Sometimes you can replace term "Anaphylaxis" with "Hypersensitivity reaction", this terms are similar.