Question

Which immune cell is primarily responsible for histamine release, resulting in red and itchy welts?

A) T lymphocyte
B) Macrophage
C) Mast cell
D) Neutrophil

Answer 1

Mast cells are primarily responsible for releasing histamine that causes red and itchy welts in type I hypersensitivity reactions.

Step-by-step explanation:

The immune cell primarily responsible for the release of histamine, leading to the formation of red and itchy welts, is the C) Mast cell. Histamine is an inflammatory molecule that mast cells produce in response to allergens or injury. In type I hypersensitivity reactions, such as those seen in allergic reactions, mast cells play a central role by releasing histamine and other inflammatory mediators. These substances increase the permeability of blood vessels, leading to the symptoms of an allergic reaction including redness, swelling, and itching.