Prehospital Trauma Life Support (PHTLS) Practice Test

What type of shock is caused by severe allergic reactions?

1. Hypovolemic shock

2. Anaphylactic shock

3. Cardiogenic shock

4. Neurogenic shock

The correct answer is: Anaphylactic shock

Anaphylactic shock is a severe and potentially life-threatening reaction that occurs in response to allergens, such as food, insect stings, or medication. It is characterized by the rapid release of histamines and other chemicals in the body, leading to widespread vasodilation, increased vascular permeability, and ultimately a significant drop in blood pressure. This type of shock presents with symptoms such as difficulty breathing, swelling, hives, and gastrointestinal distress, all of which can escalate quickly. The use of epinephrine is critical in managing anaphylactic shock as it helps reverse the effects of the allergic reaction by constricting blood vessels, improving blood flow to vital organs, and alleviating other symptoms. In contrast, hypovolemic shock results from a significant loss of blood volume, cardiogenic shock is due to the heart’s inability to pump effectively, and neurogenic shock results from damage to the spinal cord, leading to loss of sympathetic tone and vasodilation. Each of these types of shock has distinct causes and mechanisms, clearly differentiating them from anaphylactic shock, which is specifically linked to allergic reactions.