Fever in Venous Thromboembolism

Clinical Presentation

Fever was present in 7% of all Pulmonary Embolism (PE) patients in one large series, compared to 17% of patients without PE, according to the European Heart Journal 1
PE from Deep Vein Thrombosis (DVT) is specifically listed as a differential diagnosis when evaluating fever in stroke patients, as recommended by the American Heart Association/Stroke 2

The American Heart Association/Stroke recommends that workup should include both infectious and non-infectious sources, with PE from DVT specifically included in the differential, when fever is present 2
The presence of fever should not distract from considering Venous Thromboembolism (VTE), particularly when patient has risk factors for thrombosis, such as immobility, recent surgery, or cancer, as noted by the National Comprehensive Cancer Network 2, 3

The American Heart Association/Stroke suggests that first-line fever therapy includes antipyretic medications, with cooling devices for refractory cases, in patients with VTE 2
The National Comprehensive Cancer Network recommends that VTE prophylaxis is critical in at-risk populations, as patients with acute ischemic stroke without prophylaxis have a 75% chance of developing VTE 2

The American College of Radiology recommends duplex ultrasound of the lower extremity as the initial imaging modality for suspected DVT in patients with unexplained fever, with a pooled sensitivity of 94.2% and pooled specificity of 93.8% for proximal DVT 4, 5, 6
Real-time compression ultrasound and Doppler evaluation can detect proximal obstruction and identify failure of complete vein wall compression, confirming the diagnosis of DVT 6

DVT should be considered in the differential diagnosis of fever of unknown origin after more common causes have been excluded, with a reported incidence of 6% in one series 4, 5
The American College of Radiology suggests that lower extremity ultrasound be incorporated into fever of unknown origin workup algorithms 4, 5

Approximately one-third of DVT patients are asymptomatic, and clinical prediction scores combined with D-dimer are less reliable in certain populations, making it essential to consider DVT screening in high-risk immobilized patients even without classic DVT symptoms 4, 5, 6