a condition of hypersensitivity to proteins or other substances, requiring previous exposure to the allergenic substance and resulting in shock or other physical reactions
Origin of anaphylaxisModern Latin from Classical Greek ana-, intensive + phylaxis, a guarding from phylassein, to guard
A sudden, usually systemic allergic reaction, characterized by vasodilation resulting in decreased blood pressure, smooth muscle contraction resulting in shortness of breath, and hives, caused by hypersensitivity induced by a secondary exposure to a foreign substance, such as a drug or protein, after an initial sensitizing exposure.
Origin of anaphylaxisana- (pro)phylaxis
- an′a·phy·lac′tic an′a·phy·lac′toid