Which symptom is commonly associated with a febrile, nonhemolytic reaction?

A febrile, nonhemolytic reaction is primarily characterized by the development of a fever in response to a blood transfusion, which is often due to the recipient's immune response to the donor's white blood cells, platelets, or proteins. This type of transfusion reaction typically occurs within a few hours after the transfusion begins and is distinguished from hemolytic reactions, which involve the destruction of red blood cells and may produce different symptoms.

The fever, which is a common symptom in this type of reaction, can manifest as an elevated body temperature often accompanied by chills. Patients may also experience mild headache and flushing, but the hallmark symptom is indeed the fever.

Other potential symptoms associated with transfusion reactions, such as low back pain, urticaria (hives), and crackles, are more indicative of other types of transfusion complications. Low back pain is typically associated with acute hemolytic reactions, urticaria is related to allergic reactions, and crackles could indicate fluid overload or respiratory issues, which are not characteristic of a febrile, nonhemolytic reaction. Thus, fever stands out as the primary and defining symptom in this scenario.