Serum sickness
Serum sickness in humans is a reaction to proteins in antiserum derived from a non-human animal source, occurring 4–10 days after exposure. It is a type of hypersensitivity, specifically immune complex hypersensitivity (type III). The term serum sickness-like reaction (SSLR) is occasionally used to refer to similar illnesses that arise from the introduction of certain non-protein substances. It was first characterized by Clemens von Pirquet and Béla Schick in 1906.