Which of the following is a sign of anaphylaxis?

Generalized itchiness and rash are hallmark signs of anaphylaxis. Anaphylaxis is a severe allergic reaction that can occur rapidly after exposure to an allergen. One of the body's responses to an allergen is the release of histamines and other chemicals, which often leads to symptoms including itching and rashes, commonly affecting large areas of the body. This skin reaction may also be accompanied by other symptoms such as swelling or hives.

In contrast, while excessive sweating can occur in various situations, it is not a specific sign of anaphylaxis. High blood pressure is typically not present during anaphylaxis; instead, patients often experience a drop in blood pressure due to vasodilation. A rapid heart rate is a more generalized response to stress or other conditions but is less specific as a sign of anaphylaxis when compared to the classic presentations like generalized itchiness and rash.