Which symptom is associated with a febrile transfusion reaction?

A febrile transfusion reaction is characterized by an increase in body temperature, often occurring during or shortly after a blood transfusion. This reaction is typically caused by the recipient's immune response to the donor blood's white blood cells or cytokines.

When the patient's body recognizes these foreign elements, it can trigger a fever as part of the immune response. As the temperature rises, the patient may experience other symptoms such as chills and discomfort, but the hallmark sign that is most directly associated with a febrile transfusion reaction is the increasing temperature.

The other symptoms listed, while they may be associated with different types of transfusion reactions or other medical conditions, are not indicative of febrile reactions specifically. For example, shivering might occur due to chills but is not the primary indicator. Hematuria, or blood in the urine, is more commonly associated with hemolytic reactions, while joint pain can signify other issues unrelated to febrile transfusion reactions. Therefore, rising temperature distinctly points to the febrile nature of the reaction.