What is the diagnosis and treatment for a patient with fever, epigastric pain, nausea, leukocytosis (elevated leukocyte count), and mildly elevated liver transaminases (liver enzyme elevation)?

Pyogenic Liver Abscess

The most likely diagnosis is pyogenic liver abscess, which requires immediate imaging with ultrasound or CT scan, blood and abscess cultures, and treatment with broad-spectrum antibiotics (ceftriaxone plus metronidazole) combined with percutaneous drainage for abscesses >3-5 cm. 1, 2

Clinical Reasoning

This patient's presentation is highly characteristic of pyogenic liver abscess:

• Fever pattern: Persistent fever that fluctuates but never normalizes over 3 days is classic for an infectious process, particularly intra-abdominal abscess 2
• Epigastric pain with nausea: Gastrointestinal symptoms including abdominal pain, nausea, and vomiting are common manifestations of pyogenic liver abscess 1
• Marked leukocytosis (24,000): This degree of neutrophilic leukocytosis strongly suggests bacterial infection rather than viral hepatitis, which typically presents with markedly elevated transaminases (>10x normal) rather than leukocytosis 2
• Mildly elevated liver transaminases: This pattern (elevated but not dramatically so) is consistent with liver abscess rather than acute viral hepatitis 2

Diagnostic Workup

Immediate Imaging (First Priority)

• Abdominal ultrasound is the recommended initial imaging modality as it can reliably identify liver abscesses and guide percutaneous drainage 2
• CT abdomen with IV contrast should be obtained if ultrasound is equivocal, unavailable, or to better characterize abscess size, location, and multiloculation 2

Microbiological Studies

• Blood cultures (at least 2 sets) before antibiotics to identify causative organisms (commonly Klebsiella pneumoniae, E. coli, anaerobes) 2
• Abscess aspiration cultures if drainage is performed, to guide targeted antibiotic therapy 2

Additional Laboratory Tests

• Complete blood count with differential (already showing leukocytosis)
• Comprehensive metabolic panel including liver function tests
• Inflammatory markers (CRP, ESR)
• Consider amoebic serology if travel history to endemic areas, though amoebic abscess typically responds to antibiotics alone without drainage 3

Treatment Algorithm

Empiric Antibiotic Therapy (Start Immediately)

Ceftriaxone 2g IV daily PLUS metronidazole 500mg IV every 8 hours is the recommended broad-spectrum regimen covering Gram-positive, Gram-negative, and anaerobic bacteria 1

• Continue IV antibiotics for the full 4-week duration rather than transitioning to oral therapy, as oral fluoroquinolones are associated with higher 30-day readmission rates 1
• Most patients respond within 72-96 hours if the diagnosis is correct 1, 3

Drainage Decision Based on Abscess Size

For abscesses <3-5 cm:

• Antibiotics alone or with needle aspiration often sufficient 1

For abscesses >4-5 cm:

• Percutaneous catheter drainage (PCD) is first-line combined with antibiotics, with success rate of approximately 83% for large unilocular abscesses 1

Factors favoring percutaneous drainage:

• Unilocular morphology 1
• Accessible percutaneous approach 1
• Low viscosity contents 1
• Normal albumin levels 1
• Hemodynamic stability 1

Factors requiring surgical drainage:

• Multiloculated abscesses (surgical success 100% vs. percutaneous 33%) 1
• High viscosity or necrotic contents 1
• Hypoalbuminemia 1
• Abscesses >5 cm without safe percutaneous approach 1
• Percutaneous drainage failure (occurs in 15-36% of cases) 1

Source Control

• Identify and treat underlying cause as every verified source of infection should be controlled as soon as possible 1
• Other intra-abdominal infections (perforated peptic ulcer, diverticulitis, appendicitis) are common underlying causes 1, 4
• ERCP with sphincterotomy may be necessary if biliary obstruction is present, though not routinely required 1

Critical Pitfalls to Avoid

• Do not delay imaging: Ultrasound or CT should be obtained urgently, not after empiric antibiotic trial 2
• Do not use oral antibiotics: IV therapy for full 4 weeks is essential to prevent readmission 1
• Do not miss the underlying source: Failure to identify and treat the underlying cause leads to recurrence and increased morbidity 1
• Do not assume amoebic abscess without serology: While amoebic abscess can present similarly, pyogenic abscess is more common in non-endemic settings and requires different management 3
• Monitor for drainage failure: 15-36% of percutaneous drainages fail, requiring surgical intervention 1

Alternative Diagnoses to Consider (Less Likely)

While pyogenic liver abscess is most likely, briefly consider:

• Acute cholecystitis: Would show gallbladder findings on ultrasound, typically RUQ rather than epigastric pain 5
• Acute appendicitis: Would show RLQ pain, though can present with epigastric pain initially; leukocytosis of 24,000 would be unusually high 5
• COVID-19 with pancreatitis: Can present with fever, epigastric pain, and elevated liver enzymes, but would require lipase measurement and COVID testing 6