IgEmediated

IgE-mediated refers to immune responses driven by immunoglobulin E antibodies that occur in allergic diseases. In sensitization, exposure to an allergen leads to production of specific IgE, which binds to FcεRI receptors on mast cells and basophils. Upon re-exposure, allergens cross-link bound IgE, triggering rapid release of mediators such as histamine, leukotrienes, and prostaglandins, causing the characteristic immediate-type hypersensitivity reactions.

Clinical manifestations include allergic rhinitis, conjunctivitis, urticaria and angioedema, bronchial asthma, and, in severe cases, anaphylaxis. Reactions typically begin within minutes of exposure; severity depends on dose, route of exposure, and individual sensitivity.

Diagnosis relies on clinical history supported by objective tests such as skin prick testing or serum-specific IgE testing. When necessary, oral food challenges or drug challenges are used under medical supervision. Tests detect allergen-specific IgE but do not always predict reaction severity.

Management focuses on avoidance of known triggers and pharmacotherapy to relieve symptoms. First-line medications include oral and intranasal antihistamines, intranasal corticosteroids, and leukotriene receptor antagonists; short-acting beta-agonists or inhaled corticosteroids for asthma. Epinephrine is essential for anaphylaxis. Allergen immunotherapy may reduce risk and symptoms for some inhalant and venom allergies.

Epidemiology and prognosis: IgE-mediated allergies are common worldwide, often beginning in childhood and persisting into adulthood in many individuals. Proper diagnosis and management can improve quality of life and reduce risk of severe reactions.