Which sign indicates systemic infection?

• A. Redness around wound
• B. Warmth at wound site
• C. Purulent drainage from wound
• D. Fever

Answer: (D)

Systemic infection shows itself through signs that involve the whole body, not just the wound area. Fever is a body-wide response caused by immune chemicals called pyrogens that tell the brain to raise the body's temperature. This systemic response is part of fighting infection and often accompanies other systemic symptoms like malaise or chills.

Local signs like redness and warmth at the wound occur from increased blood flow and inflammation at the specific site, while purulent drainage reflects pus formation at the wound itself. These are localized rather than systemic features.

So fever best indicates systemic involvement, whereas the other signs point to a localized infection at the wound.