What Will Be the Immediate Action of Allergen When It

Question

What will be the immediate action of allergen when it enters the body for a second time?
A)degranulation
B)bonding of allergen to adjacent IgE binding sites on mast cells and basophils
C)binding of IgE by the Fc region to mast cells and basophils
D)Histamine acts on smooth muscle.
E)Prostaglandins cause vasodilation and increased vascular permeability.

Accepted Answer

When an allergen enters the body for the second time, it will bind to adjacent IgE binding sites on mast cells and basophils. This will cause these cells to undergo degranulation and release inflammatory mediators such as histamine and prostaglandins, which will cause an allergic reaction. This reaction is known as a type I hypersensitivity reaction.