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