Hypersensitivity reactions with an overview on anaphylaxis

—Hypersensitivity Reaction : A state of altered reactivity in which the body reacts with an exaggerated immune response to a foreign agent. —These reactions may be damaging, uncomfortable, or occasionally fatal. Coombs and Gell classified hypersensitivity into 4 types. Anaphylaxis: —Ana (without), phylaxis (protection). —Acute multi-systemic allergic reaction involving the skin, airway, vascular system, and GI. —Anaphylaxis is defined as a serious allergic or hypersensitivity reaction (type 1) that is rapid in onset and may cause death.