Which type of blood cell is primarily involved in the allergic response?

Eosinophils are the type of blood cells that play a significant role in the allergic response. These cells are a type of white blood cell, specifically granulocytes, and they are particularly involved in combating parasitic infections and mediating allergic reactions. When an allergen triggers an immune response, eosinophils are recruited to the site of inflammation. They release various inflammatory mediators, including histamines, cytokines, and chemokines, which contribute to the symptoms seen in allergic reactions.

In contrast, neutrophils primarily respond to bacterial infections and are key players in the innate immune system, while monocytes differentiate into macrophages and are involved in phagocytosis and immune regulation. B lymphocytes are responsible for producing antibodies and play a central role in the humoral immune response, but they are not the primary cells engaged in immediate allergic responses. Thus, eosinophils are distinctly recognized for their involvement in allergies, making them the correct choice.