state of previously immunized body in which tissue damage results from the immune response to a further dose of antigen.
Hypersensitivity to an agent caused by an immunologic response to an initial exposure
Hypersensitivity; a local or general reaction of an organism following contact with a specific allergen to which it has been previously exposed and to which it has become sensitized.
An exaggerated response by the immune system to a drug or other substance.
An inflammatory response to an exogenous environmental antigen or an endogenous antigen initiated by the adaptive immune system. [GOC:jal, ISBN:0781735149 "Fundamental Immunology"]
Excludes
allergic reaction NOS to correct medicinal substance properly administered (995.27)
allergy to existing dental restorative materials (525.66)