Can Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) cause fever?

Can DVT and Pulmonary Embolism Cause Fever?

Yes, both DVT and PE can cause fever, though it occurs in a minority of patients and is typically low-grade. Fever should prompt evaluation for these conditions, particularly when other common infectious causes have been excluded.

Frequency and Characteristics of Fever in VTE

Deep Vein Thrombosis

• Fever occurs in approximately 4.9% of patients with acute DVT at presentation 1
• When present, fever in DVT patients is associated with significantly worse outcomes, including doubled mortality risk (5.8% vs 2.9% in those without fever) 1
• DVT should be considered in the differential diagnosis of fever of unknown origin after more common causes are excluded, with a reported incidence of 6% in fever workup series 2

Pulmonary Embolism

• Low-grade fever occurs in 14% of patients with angiographically proven PE who have no other identifiable source of fever 3
• High fever, while rare, can occur with PE and does not require the presence of pulmonary hemorrhage or infarction 3
• Fever was present in 7% of all PE patients in one large series, compared to 17% of patients without PE 4
• PE from DVT is specifically listed as a differential diagnosis when evaluating fever in stroke patients 4

Clinical Significance and Pathophysiology

Fever in VTE represents a direct inflammatory response to thrombosis rather than infection, though the exact mechanism is not fully elucidated 5, 3. The fever typically:

• Resolves rapidly with anticoagulation therapy 5
• Can occur with normal inflammatory markers (normal WBC and CRP) 5
• May be intermittent rather than continuous 5

Diagnostic Approach When Fever is Present

Initial Evaluation

• Workup should include both infectious and non-infectious sources, with PE from DVT specifically included in the differential 4
• Clinical signs of DVT are often present in PE patients with otherwise unexplained fever 3
• Duplex ultrasound of lower extremities has 94.2% sensitivity and 93.8% specificity for proximal DVT and should be considered in fever workup 2

Critical Pitfall

Approximately one-third of DVT patients are asymptomatic, making it essential to maintain high clinical suspicion even without classic DVT symptoms in high-risk immobilized patients 2. The presence of fever should not distract from considering VTE, particularly when:

• Patient has risk factors for thrombosis (immobility, recent surgery, cancer) 4
• Fever persists despite antibiotic therapy
• Other infectious sources have been excluded 4

Prognostic Implications

The presence of fever in DVT patients carries significant prognostic weight 1:

• Multivariate analysis confirms fever independently increases mortality (hazard ratio 2.00,95% CI 1.44-2.77) 1
• Fatal PE is more common in DVT patients presenting with fever (0.7% vs 0.1%) 1
• Infection-related deaths are also more frequent (1.1% vs 0.3%) 1

Management Considerations

• Prompt anticoagulation is essential as fever typically resolves rapidly with appropriate treatment 5
• First-line fever therapy includes antipyretic medications, with cooling devices for refractory cases 4
• VTE prophylaxis is critical in at-risk populations, as patients with acute ischemic stroke without prophylaxis have a 75% chance of developing VTE 4

Key Clinical Pearls

• Fever need not be accompanied by pulmonary hemorrhage or infarction to indicate PE 3
• The absence of elevated inflammatory markers does not exclude VTE as a cause of fever 5
• Central fever should remain a diagnosis of exclusion only after VTE has been adequately evaluated 4
• Clinical evidence of DVT should be actively sought in any patient with PE and unexplained fever 3