Can D-dimer Be Elevated in a Patient with an Upper Arm Abscess?
Yes, D-dimer can absolutely be elevated in a patient with an upper arm abscess, as infection and inflammatory states are well-established causes of D-dimer elevation, even in the absence of thrombotic disease. 1
Mechanism of D-dimer Elevation in Infection
- D-dimer is a fibrin degradation product that results from systemic degradation of vascular thrombi through the fibrinolytic mechanism, making it a marker of both coagulation activation and fibrinolysis 1
- Severe infection or inflammatory disease frequently elevates D-dimer, particularly in hospitalized patients, through activation of the coagulation cascade independent of thrombotic events 1
- Sepsis and disseminated intravascular coagulation cause D-dimer elevation with 94-100% sensitivity when measured within 24 hours 1
Clinical Context and Expected Findings
- In a large emergency department study of 1647 patients with elevated D-dimer, infection was the most frequent diagnosis (15.6%), even more common than venous thromboembolism (12.1%) 2
- An abscess represents a localized infection with inflammatory response that can trigger systemic coagulation activation, resulting in elevated D-dimer levels 1
- The degree of D-dimer elevation may vary based on the extent of the infection and individual patient factors 1
Important Clinical Implications
- D-dimer has high sensitivity but low specificity for thrombotic events—a positive D-dimer cannot diagnose VTE and requires further investigation if thrombosis is clinically suspected 1, 3
- In unselected emergency department patients with elevated D-dimer, infection, neoplasia, anemia, heart failure, and venous thromboembolism were all significantly associated with elevation 4
- D-dimer testing has severely limited diagnostic value in patients with active infection or sepsis due to high false-positive rates regardless of VTE status 3
Clinical Decision-Making Algorithm
- If the patient has an obvious source of infection (upper arm abscess) and no clinical signs or symptoms suggesting VTE (no leg swelling, chest pain, dyspnea, hemoptysis), the elevated D-dimer should be attributed to the infection rather than prompting extensive thrombosis workup 1, 3
- Only pursue imaging for VTE if clinical probability is moderate-to-high based on validated scores (Wells or Geneva criteria), regardless of D-dimer level 3
- For patients with low clinical probability of VTE and an obvious alternative explanation (infection), a negative D-dimer would have ruled out VTE, but a positive D-dimer in this context does not mandate imaging 1, 3
Critical Pitfall to Avoid
- Never use a positive D-dimer alone to diagnose thrombotic disease—the specificity is only 35% and numerous non-thrombotic conditions including infection cause elevation 1, 3
- D-dimer levels can be elevated in numerous conditions other than thrombosis, including infection or inflammatory states, recent surgery or trauma, pregnancy, advanced age, and malignancy 1