Fever

Background

Definition

• Fever is a core body temperature ≥38ºC that occurs as a part of a febrile response (compared to hyperthermia which may be from any cause)

Differential Diagnosis

Diagnosis	Clinical Clues
Infection	Leukocytosis, sepsis, increasing oxygen requirements, altered mentation
Venous thromboemoblism	Swollen, tender arm or leg, increasing oxygen requirements
Drug-related	No improvement on antibiotics, compatible medication exposure
Post-surgical	Recent surgery, rule out surgical site infection
Paroxysmal sympathetic hyperactivity	Tachycardia, tachypnea, dystonic posturing, episodic, associated with stimulation, traumatic brain injury
Neurogenic fever	No other cause identified, hypothalamic injury, subarachnoid or intraventricular hemorrhage, recurrent, no improvement with treatment