All of the following are true of hypersensitivity EXCEPT
A) it is due to an altered immune response.
B) it requires previous exposure to an antigen.
C) it is synonymous with ʺallergy.ʺ
D) it occurs when an individual is exposed to an allergen for the first time.
E) it occurs in the presence of an antigen.

Question

Quizplus · Accepted Answer

Hypersensitivity reactions require previous exposure to an antigen to sensitize the immune system; they do not occur upon first exposure.

All of the Following Are True of Hypersensitivity EXCEPT