Which antibody causes allergies?

The antibody primarily responsible for causing allergies is IgE. This immunoglobulin plays a crucial role in the body’s immune response to allergens, which are typically harmless substances that can trigger allergic reactions in sensitive individuals. When an allergen is encountered, IgE binds to it and initiates the release of histamines and other chemicals from mast cells and basophils. This release leads to the symptoms commonly associated with allergies, such as itching, swelling, and inflammation.

In contrast, the other antibodies mentioned serve different functions in the immune system. IgM is mainly involved in the initial immune response and helps in the formation of complexes that activate complement. IgG provides long-term protection and is involved in recognizing and neutralizing pathogens. IgA primarily plays a role in mucosal immunity, protecting against pathogens in areas such as the gastrointestinal tract and respiratory tract. Thus, while all these antibodies are vital for different aspects of immune function, IgE is specifically linked to allergic reactions.