Which immunoglobulin is associated with allergic reactions?

The immunoglobulin associated with allergic reactions is IgE. This antibody plays a crucial role in the body's immune response to allergens, such as pollen, dust mites, and certain foods. When an individual is exposed to an allergen, IgE antibodies are produced and bind to the allergen, leading to the release of histamines and other chemicals from mast cells and basophils. This release is what causes the symptoms of allergic reactions, such as itching, swelling, and respiratory issues.

The other immunoglobulins, while important in the immune system, are typically associated with different functions. IgA is primarily found in mucosal areas and provides a first line of defense against pathogens; IgM is the first antibody produced in response to an infection; and IgG is the most abundant antibody in serum and provides long-term protection against pathogens after infection or vaccination. These functions highlight the specialized role of IgE in managing allergic responses.