Question

All of the following are true of hypersensitivity except ______.

A. it occurs in the presence of an antigenB. it is synonymous with allergyC. it occurs when an individual is exposed to an allergen for the first timeD. it is due to an altered immune responseE. it requires previous exposure to an antigen

Answer 1

Hypersensitivity reactions occur when an individual is exposed to an antigen to which they have previously been sensitized. This means that a hypersensitivity reaction requires previous exposure to an antigen.

Step-by-step explanation:

The statement that is not true of hypersensitivity is:

C. it occurs when an individual is exposed to an allergen for the first time

Hypersensitivity reactions occur when an individual is exposed to an antigen to which they have previously been sensitized. This means that a hypersensitivity reaction requires previous exposure to an antigen. Hypersensitivity reactions can range from mild to severe and are a result of an altered immune response.

Answer 2

The correct option is C.

Step-by-step explanation:

Hypersensitivity is the process by which the immune system produce excessive reactions when exposed to certain antigens. There are four types of hypersensitivity, type 1 to type IV.

For hypersensitivity to occur some conditions must be fulfilled. For instance, an antigen must be present, the immune system must have been exposed to the antigen previously, etc. Hypersensitivity does not occur when the immune system is been exposed to an antigen for the first time.