Which white blood cell type is primarily responsible for allergic reactions?

The white blood cell type primarily responsible for allergic reactions is basophils. These cells play a crucial role in the body's immune response to allergens. When an individual is exposed to an allergen, basophils release histamine and other inflammatory mediators. This release is part of the body's attempt to combat what it perceives as a harmful substance. Histamine causes many of the classic symptoms of allergic reactions, including swelling, redness, and itching, by increasing blood flow and allowing other immune cells to reach the site of the allergen more effectively.

While eosinophils also play a role in allergic responses, particularly in the late phase of the reaction and in fighting parasitic infections, basophils are specifically involved in the immediate hypersensitivity reaction associated with allergies. Their activity is pivotal in the initiation and orchestration of the allergic response, making them the most relevant cell type for this context.