Anaphylactic shock is

Anaphylactic shock is

• A. A mild reaction that causes destruction of erythrocytes
• B. A moderate reaction that causes hives
• C. A severe, life-threatening reaction that occurs seconds after an antigen enters the circulation
• D. A severe reaction caused by rapid loss of blood or other bodily fluid

Answer: (C)

Anaphylactic shock is a rapid, life-threatening allergic reaction driven by an immune response to an antigen. When the reaction occurs, IgE-mediated activation of mast cells and basophils releases histamine and other mediators all over the body. This causes sudden vasodilation and leakage of fluid from vessels, leading to a dangerous drop in blood pressure, along with airway swelling and bronchoconstriction that can block breathing. Because it can develop within seconds to minutes after exposure, it demands immediate emergency treatment, typically with epinephrine, plus airway and fluid support. The other descriptions don’t fit: a mild reaction with destruction of erythrocytes points to a hemolytic process; a moderate reaction with hives describes a less severe cutaneous response; and a rapid loss of blood or bodily fluid describes hypovolemic shock from non-immune causes rather than the immune-mediated mechanism of anaphylaxis.

Anaphylactic shock is a rapid, life-threatening allergic reaction driven by an immune response to an antigen. When the reaction occurs, IgE-mediated activation of mast cells and basophils releases histamine and other mediators all over the body. This causes sudden vasodilation and leakage of fluid from vessels, leading to a dangerous drop in blood pressure, along with airway swelling and bronchoconstriction that can block breathing. Because it can develop within seconds to minutes after exposure, it demands immediate emergency treatment, typically with epinephrine, plus airway and fluid support. The other descriptions don’t fit: a mild reaction with destruction of erythrocytes points to a hemolytic process; a moderate reaction with hives describes a less severe cutaneous response; and a rapid loss of blood or bodily fluid describes hypovolemic shock from non-immune causes rather than the immune-mediated mechanism of anaphylaxis.