What is a severe allergic reaction that impacts multiple body systems called?

A severe allergic reaction that impacts multiple body systems is called anaphylaxis. This condition is characterized by the rapid onset of symptoms that can involve various organ systems, including the respiratory, cardiovascular, and gastrointestinal systems. The body's immune response is triggered in a dramatic way, causing widespread release of chemicals such as histamine that lead to symptoms like difficulty breathing, swelling, hives, a drop in blood pressure, and in severe cases, can result in loss of consciousness or even death if not treated promptly.

Anaphylaxis is typically a life-threatening situation that requires immediate medical intervention, often with the administration of epinephrine to counteract the severe reaction. Other options such as shock, sepsis, or general allergic reactions do not specifically describe the multi-system involvement and rapid progression characteristic of anaphylaxis. Shock may refer to a state of inadequate blood flow that can result from various causes, while sepsis is a systemic infection response, and an allergic reaction could be a milder form not involving multiple systems or not requiring emergency treatment. Therefore, the term anaphylaxis captures the critical nature and systemic involvement of this severe allergic response.