Final answer:
Anaphylactic shock is a severe type I hypersensitivity reaction causing rapid mast cell degranulation, histamine release, and resulting in vasodilation, bronchial muscle contractions, and a marked drop in blood pressure. Epinephrine is the emergency treatment of choice as it increases blood pressure and relaxes smooth muscle to counteract the symptoms of anaphylaxis. Those with known severe allergies should carry epinephrine auto-injectors for immediate response.
Step-by-step explanation:
Anaphylactic Shock Pathophysiology
The pathophysiology of anaphylactic shock, also known as anaphylaxis, involves a systemic and potentially life-threatening type I hypersensitivity reaction. When an individual with a severe allergy encounters an allergen, such as shellfish, peanuts, bee stings, or penicillin, it triggers systematic mast cell degranulation. This leads to a rapid release of histamine and other inflammatory mediators into the bloodstream, resulting in widespread vasodilation, increased vascular permeability, contractions of bronchial smooth muscle, and a sudden drop in blood pressure. The swelling of the tongue and trachea, along with respiratory distress, can rapidly ensue, leading to shock and potential fatality within minutes. Treatment includes administering epinephrine immediately, as it raises blood pressure, relaxes bronchial smooth muscle, and reduces airway swelling, which is crucial to counteracting anaphylactic symptoms and saving the patient's life.
Patients with known severe allergies are often advised to carry epinephrine auto-injectors, such as EpiPen®, to provide emergency treatment to prevent the full onset of anaphylaxis. Additionally, follow-up care may involve antihistamines, steroids, and in some cases, antibiotics depending on the secondary effects of the shock.