Which is a classic symptom of anaphylactic shock?

Urticaria, commonly known as hives, is indeed a classic symptom of anaphylactic shock. This condition is characterized by a severe and rapid allergic reaction that can affect multiple systems in the body. Urticaria results from the release of histamines and other chemicals from mast cells and basophils, leading to raised, itchy welts on the skin.

The presence of urticaria during anaphylactic shock indicates that the immune system is responding excessively to an allergen, which could also contribute to other symptoms such as difficulty breathing, swelling of the throat, and hypotension. Recognizing urticaria is important as it can often be an early sign of an impending anaphylactic episode, allowing for prompt intervention.

While hypotension, or low blood pressure, is also a critical sign of anaphylaxis and plays a significant role in assessing the severity of the reaction, urticaria is considered a more classic dermatological manifestation associated with the immediate hypersensitivity reaction. Other options, such as hypothermia or bradypnea, are not characteristic signs of anaphylactic shock, further emphasizing why urticaria stands out as the classical symptom in this context.