Final answer:
Anaphylactic shock causes the blood vessels to dilate dramatically due to a severe allergic reaction, leading to potentially fatal respiratory distress and low blood pressure. Immediate treatment with epinephrine is crucial to constrict the blood vessels and manage the reaction.
Step-by-step explanation:
Anaphylactic shock is a form of distributive shock where the blood vessels experience widespread vasodilation. This is a result of a severe allergic reaction that causes the systemic release of histamines. Anaphylactic shock is a systemic and potentially life-threatening type I hypersensitivity reaction that can lead to respiratory distress, plummeting blood pressure, and without prompt treatment with epinephrine, it could be fatal. This extreme vasodilation reduces vascular resistance, leading to decreased blood pressure that can quickly become life-threatening.
The first line of treatment for anaphylactic shock typically involves administration of epinephrine, which constricts blood vessels, increases blood pressure, relaxes smooth muscles in the lungs, modulates heart rate, and reduces swelling that might block the airways. Further medical care may include oxygen therapy, antihistamines, or steroids depending on the severity of the reaction and response to initial treatment.