Gas-forming pyogenic liver abscess (GPLA) is an uncommon and potentially fatal disease that represents 7-24% of pyogenic liver abscess cases. Diabetes mellitus is a well-known risk factor, and the main etiological agent is Klebsiella pneumoniae. Escherichia coli is also associated with gas formation, particularly in the presence of biliary disorders. In South America, parasitic diseases have been described as predisposing factors for pyogenic liver abscesses and should be considered during etiological investigation. Clinical symptoms include fever and abdominal pain, but the presentation can be non-specific. Diagnosis is facilitated by abdominal ultrasound and computed tomography scanning (Figure A); the presence of air is observed in less than 36% of chest roentgenograms, simulating pneumoperitoneum (Figure B). The fatality rate due to gas-forming abscesses is higher than that due to non-gas-forming lesions. Other unfavorable prognostic factors are the presence of multidrug-resistant organisms, a high blood urea nitrogen level and an APACHE II score ≥15 at admission. Treatment includes hemodynamic support, antibiotic therapy and early drainage.
