Allergen-specific immunoglobulin E (IgE) is a type of antibody produced by the immune system in response to exposure to specific allergens—substances that trigger allergic reactions in sensitive individuals. IgE plays a central role in allergic diseases such as asthma, hay fever (allergic rhinitis), food allergies, and atopic dermatitis. Unlike other immunoglobulins (e.g., IgG or IgM), IgE is present in very low concentrations in the blood but is highly specialized for mediating allergic and parasitic responses.
