Patient has been given penicillin 48 hours ago, with no history of drug allergy. Now he develops wheeze and hemolysis. Antibody for penicillin is positive. Type of hypersensitivity is which of the following

Administration of penicillin causing no symptoms in 48 hours with no previous history of allergy rules out type I hypersensitivity reaction. The patient presented with hemolysis which can be because of antibody formation against red cells. The formation of autoantibody is a feature associated with type II hypersensitivity reaction. Thus, it becomes the answer over here. Clinically, antibody-mediated cell destruction and phagocytosis occur in multiple situations: Transfusion reactions, in which cells from an incompatible donor react with and are opsonized by preformed antibody in the host Hemolytic disease of the newborn: antigenic difference between the mother and fetus Autoimmune hemolytic anemia, agranulocytosis, and thrombocytopenia, in which individuals produce antibodies to their own blood cells, which are then destroyed. Certain drug reactions, in which a drug acts as a “hapten” by attaching to plasma membrane proteins of red cells and antibodies are produced against the drug-protein complex.