Which type of leukocyte is primarily involved in allergic reactions?

Eosinophils are primarily involved in allergic reactions due to their role in mediating the body's response to allergens. When an allergen is encountered, eosinophils are recruited to the site of inflammation and release substances that can help combat parasites but are also implicated in the pathophysiology of allergic reactions. They respond to certain cytokines and mediators associated with allergies, contributing to the inflammatory response that can lead to symptoms such as itching, swelling, and respiratory issues.

In allergic conditions, eosinophils can become activated and release inflammatory substances, which can exacerbate the symptoms of allergies and asthma. Their increased presence can also be indicative of allergic disorders, such as hay fever or asthma, where they contribute to the inflammation and tissue damage associated with an overactive immune response.

Neutrophils and monocytes play different roles in the immune response, mainly associated with fighting infections and phagocytosis, while basophils participate in inflammatory reactions as well, often releasing histamine during an allergic response, but they are not the primary leukocytes involved as are eosinophils in these particular reactions.