Which class of immunoglobulin is typically associated with allergic responses?

The class of immunoglobulin that is typically associated with allergic responses is IgE. This immunoglobulin plays a crucial role in the body's defense against parasitic infections and is also the primary mediator in allergic reactions. When an individual is exposed to an allergen, such as pollen, pet dander, or certain foods, their immune system may produce IgE antibodies specific to that allergen.

Upon subsequent exposure to the same allergen, these IgE antibodies bind to mast cells and basophils, leading to the release of histamine and other inflammatory mediators. This release is responsible for the symptoms associated with allergic responses, such as itching, swelling, and difficulty breathing.

In contrast, IgG is the most abundant immunoglobulin and is primarily involved in the secondary immune response and neutralizing pathogens. IgM is usually the first antibody produced in response to an infection and plays a significant role in the initial stages of immune responses. IgA is mainly found in mucosal areas, such as the gut and respiratory tract, and is important for mucosal immunity. Each of these other immunoglobulin classes has distinct roles in immunity but does not play a direct role in mediating allergic reactions like IgE does.