Which is NOT a cardinal sign of infection?

Which is NOT a cardinal sign of infection?

• A. hyperthermia
• B. rubor (redness)
• C. calor (heat)
• D. dolor (pain)

Answer: (A)

The main concept is distinguishing the local signs of inflammation from a systemic response. The four classic cardinal signs of acute inflammation arise from local vascular changes: redness (rubor) and warmth (calor) come from increased blood flow due to vasodilation, swelling (tumor) from fluid leakage, and pain (dolor) from mediator-irritated nerves. Fever or hyperthermia is a systemic response driven by pyrogens acting on the hypothalamus; it signals a whole-body reaction to infection, not a local inflammatory sign. Because hyperthermia is systemic rather than a local sign, it is not one of the cardinal signs of infection. The other signs listed describe local inflammatory changes and fit as cardinal signs.

The main concept is distinguishing the local signs of inflammation from a systemic response. The four classic cardinal signs of acute inflammation arise from local vascular changes: redness (rubor) and warmth (calor) come from increased blood flow due to vasodilation, swelling (tumor) from fluid leakage, and pain (dolor) from mediator-irritated nerves. Fever or hyperthermia is a systemic response driven by pyrogens acting on the hypothalamus; it signals a whole-body reaction to infection, not a local inflammatory sign. Because hyperthermia is systemic rather than a local sign, it is not one of the cardinal signs of infection. The other signs listed describe local inflammatory changes and fit as cardinal signs.