hypersensitivity reaction to the ingestion or injection of a substance (a protein or drug) resulting from prior contact with a substance
例句
用作名词(n.)
Every year these allergies cause about thirty thousand cases of anaphylaxis,a severe reaction that requires immediate treatment.每年这些过敏造成约三万宗过敏性反应，这是一种需要立即就医的严重反应。
