Hypersensitivity:
The physiological state necessary for a subject's manifesting an allergic response or reaction; the state is dependent on the administration of a hapten or allergen to a susceptible individual, and the development of antibodies and immune mechanisms capable of being activated by a subsequent administration of the haptene. Hypersensitivity may exist but not be manifested until a second administration of hapten occurs. The dose of hapten (or drug) required to produce the allergic response may be smaller, larger, or the same size as the dose required for the drug to produce its characteristic pharmacologic effects; hence hypersensitivity is not the same as sensitivity and the two words should not be used as synonyms. The nature of the response to haptene in a hypersensitive subject is determined by the immune mechanisms and effector organs and is not, in general, related to the nature of the hapten; the allergic response in the hypersensitive subject is generally qualitatively
different from the expected pharmacodynamic response to the hapten or drug, being determined by the immune system, rather than by the receptor(s) that mediate that drug's pharmacodynamic effect.
(
http://www.bumc. bu.edu/Dept/ Content.aspx? DepartmentID= 65&PageID= 7800#Hypersensit ivity)
Supersensitivity:
An extreme and high degree of sensitivity to a drug or chemical. Usually a high degree of sensitivity induced by some specific procedure such as denervation, administration of another drug, etc. Sensitivity to a drug, of some degree, is inherent in every organism; supersensitivity is a state that has had to be produced in the organism. **In the supersensitive subject, the actions of the drug are qualitatively like those observed in a subject of normal sensitivity, and unlike those produced in a subject who is hypersensitive to the drug.**
(
http://www.bumc. bu.edu/Dept/ Content.aspx? DepartmentID= 65&PageID= 7802#Supersensit ivity)
Dorland's Medical Dictionary
--supersensitivity: abnormally increased sensitivity
--hypersensitivity: a state of altered reactivity in which the body reacts with an exaggerated or inappropriate immune response to what is perceived to be a foreign substance. The resulting hypersensitivity reactions are usually subclassified as types I–IV on the basis of the Gell and Coombs classification of immune responses; see individual types under hypersensitivity reaction at reaction.