Which is a common symptom of systemic infections but not localized infections?

Chills and fever are common symptoms of systemic infections because they indicate a body-wide response to pathogens. When the body senses an infection, the immune system releases chemicals called pyrogens, which can raise the body's temperature to create an environment less favorable for the invading microorganisms. This elevation in temperature, or fever, is often accompanied by chills, as the body feels cold while it is trying to warm up to a higher temperature set point.

In contrast, localized infections typically present symptoms that are confined to the affected area, such as localized pain or swelling at a specific site. Itching can also occur in localized conditions, particularly those involving the skin. Therefore, chills and fever serve as indicators of a systemic response, while other symptoms reflect more localized issues. This distinction is important for understanding the nature and severity of infections, as systemic infections can often be more severe and require different medical interventions compared to localized ones.