Management of Leukocytosis with Neutrophilia (WBC 14.6, Neutrophils 73%)
Initiate empirical broad-spectrum antimicrobial therapy immediately if the patient is febrile or shows any signs of infection, as bacterial infection is the most common cause of neutrophilia and delay can be life-threatening. 1
Initial Assessment and Risk Stratification
This degree of leukocytosis (WBC 14.6 × 10⁹/L) with neutrophilia (73%) is commonly reactive rather than malignant, particularly in the context of acute infection or inflammatory processes. 2, 3 However, immediate evaluation is critical to distinguish between:
- Acute bacterial infection (most common) - requires urgent antimicrobial therapy 1
- Inflammatory/stress response - from trauma, surgery, or acute illness 3
- Hematologic malignancy - less likely at this level but must be excluded 4
Key clinical features to assess immediately:
- Fever, hypotension, or signs of sepsis 1
- Source of infection (respiratory, urinary, abdominal, skin/soft tissue) 1
- Recent trauma, surgery, or significant physiologic stress 2, 3
- Constitutional symptoms (weight loss, night sweats, bruising, fatigue) suggesting malignancy 3
Empirical Antibiotic Management
For febrile patients or suspected infection, start antibiotics immediately without waiting for culture results: 1
- First-line oral therapy (if hemodynamically stable, no severe sepsis): Levofloxacin 500mg daily OR ciprofloxacin 500mg twice daily 1
- Intravenous therapy (if severe infection, sepsis, or hemodynamically unstable): Ceftazidime, meropenem, or piperacillin-tazobactam 2, 1
- If pneumonia suspected: Add macrolide antibiotic (azithromycin or clarithromycin) to β-lactam for atypical organism coverage 1
Diagnostic Workup
Essential immediate tests:
- Peripheral blood smear review to assess neutrophil morphology, presence of toxic granulations, left shift, and exclude blasts 3, 5, 6
- Blood cultures (before antibiotics if possible, but do not delay treatment) 1
- Site-specific cultures based on suspected infection source 1
- Basic metabolic panel and renal function 2
Important caveat: Leukocytosis >17 × 10⁹/L may indicate infection (commonly chest or urinary), but this patient's WBC of 14.6 is below that threshold and represents a moderate elevation. 2 Leucocytosis and neutrophilia occur in 45% and 60% of patients with trauma as a reactive response, not necessarily infection. 2
Monitoring and Follow-up
Daily assessment required until resolution: 2
- Fever trends and vital signs
- Clinical response to antibiotics
- Repeat CBC to monitor WBC trajectory
If patient becomes afebrile within 48 hours and clinically stable:
- Continue antibiotics for appropriate duration based on infection source 2
- Consider transition to oral antibiotics if IV therapy was initiated 2
If fever persists beyond 48 hours despite antibiotics:
- Reassess for alternative infection sources 2
- Consider broadening antibiotic coverage 2
- Evaluate for fungal infection if fever persists >4-6 days 2
When to Consider Hematologic Malignancy
Bone marrow examination is indicated if: 4
- Peripheral smear shows blasts or immature cells 5, 6
- Constitutional symptoms present (fever, weight loss, bruising, fatigue) 3
- Abnormalities in other cell lines (anemia, thrombocytopenia) 4
- Leukocytosis persists without clear infectious/inflammatory cause 3
Emergency leukapheresis may be required if: 4
- WBC >100 × 10⁹/L with symptoms of leukostasis (this patient does not meet criteria) 4
Special Considerations
Non-infectious causes to consider if infection excluded: 3
- Medications (corticosteroids, lithium, G-CSF)
- Smoking
- Obesity
- Chronic inflammatory conditions
- Recent surgery, trauma, or emotional stress
- Asplenia
This moderate elevation (WBC 14.6) with predominant neutrophilia most commonly represents acute bacterial infection or physiologic stress response and should prompt immediate evaluation for infection source and empirical antibiotic therapy if clinically indicated. 1, 3