IgE Mediated Hypersensitivity, also known as Type I Hypersensitivity, is a specific type of allergic reaction that is mediated by immunoglobulin E (IgE) antibodies. It is characterized by an excessive immune response to harmless environmental substances, known as allergens. IgE antibodies are produced by specialized immune cells called B lymphocytes in response to exposure to allergens.
During an initial exposure to an allergen, the immune system recognizes it as foreign and stimulates the production of specific IgE antibodies. These antibodies bind to specific receptors on the surface of mast cells and basophils, which are key players in the immune response. Upon subsequent exposure to the same allergen, the allergen binds to the IgE antibodies attached to these cells, triggering the rapid release of various inflammatory substances, such as histamine, leukotrienes, and cytokines.
The release of these mediators initiates a cascade of events, leading to the typical symptoms of an allergic reaction, such as itching, swelling, redness, hives, and in severe cases, respiratory distress or anaphylaxis. Common examples of IgE-mediated hypersensitivity conditions include allergic rhinitis (hay fever), asthma, atopic dermatitis (eczema), and food allergies.
Diagnosis of IgE Mediated Hypersensitivity often involves medical history evaluation, physical examination, and specific tests such as skin prick tests or blood tests like the ImmunoCAP test. The management of IgE-mediated hypersensitivity involves allergen avoidance, use of antihistamines or corticosteroids to control symptoms, and in some cases, allergen immunotherapy to desensitize the immune system.
