Which type of white blood cells stains reddish-orange and is involved in controlling allergic reactions?

Eosinophils are the type of white blood cells that stain reddish-orange and play a crucial role in controlling allergic reactions. They are particularly involved in combating parasitic infections and mediating inflammatory responses associated with allergies and asthma. Their distinct coloration when stained arises from the presence of granules filled with proteins that bind to acidic dyes. This property allows for their identification under a microscope, distinguishing them from other types of white blood cells.

Furthermore, the function of eosinophils in allergic reactions involves the release of various substances that can modulate inflammation and tissue response. For instance, they can release histaminase, which breaks down histamine, thereby helping to reduce the severity of allergic symptoms. This role underscores their importance in the immune response, especially in conditions such as hay fever, asthma, and other allergic diseases.