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.
Diagnosis of Allergic Diseases
An IgE blood test measures the levels of total IgE (general amount in the blood) or allergen-specific IgE (directed at particular allergens like pollen, foods, or dust mites). Elevated levels of allergen-specific IgE indicate sensitization, meaning the immune system has developed an allergic response to that substance.
Conditions Diagnosed: It’s used to confirm allergies in conditions such as: