Original case by Brandon Fainstad, MD.
Edits, updates and graphics by Yilin Zhang, MD.
- Recognize the most common organisms that cause liver abscesses
22 year old previously healthy man with two days of fever, night sweats and RUQ pain. He has had an unintentional 10lb wt loss in the past 6wks and a self resolving flu-like illness 6 mos ago. He denies nausea/vomiting, diarrhea, cough, SOB, dysuria, skin or hair changes. He has no past medical history and does not take medications. He grew up in China, moved to the US 6 years ago. He last traveled to China and Japan two years ago and denies any additional international travel. He denies any tobacco, EtOH or injection drug use.
On exam he is febrile to 38.6C, HR 110 bpm, BP 125/70 and SpO2 96%. His abdomen is soft, tender in the RUQ without a Murphy’s sign or rebound tenderness. Labs are significant for WBC 14k, Tbili 2.1. CBC and BMP are otherwise normal.
His CT imaging showed the following:
What are the possible etiologies for this liver lesion in an otherwise healthy 22 year old man?
How would you further evaluate him?
- Infectious work-up including blood cultures x 2
- Empiric initiation of antibiotics
- IR consultation for aspiration of liver lesion – eventually grew out Klebsiella pneumoniae
A significant portion of liver abscesses occur secondarily from either underlying hepatobiliary disease. instrumentation, bowel disease or from hematogenous spread. These secondary liver abscesses tend to be polymicrobial – enteric GNRs and anaerobes. Hematogenous spread is strongly suggested by GPC abscessor monomicrobial abscess.
Demographics and past medical history are in particular helpful in distinguishing between different potential causes of liver abscesses.
Klebsiella primary liver abscess (KLA) can occur in the absence prior abdominal/hepatobiliary disease or intervention. It is most common in Asians (in ffAsia or in non-Asian countries). In Taiwanese populations, there is an association of K. pneumoniae abscesses with colorectal cancer but its unclear if this applies to other populations1.
A minority of patients with KLA will develop metastatic sites of infection including endopthalmitis, meningitis or brain abscesses2. Risk factors for developing this are the presence of virulence factors such as K1 capsule.
How is it treated?
- IR aspiration or placement of indwelling percutaneous drain
- In some cases (larger abscesses or mulilobulated abscesses), surgical drainage may be necessary
- Initially broad spectrum covering GPCs, GNRs and anaerobes
- Narrow antibiotics as above
- Duration of antibiotics is often 2-6 weeks (typically IV, though oral can be considered for long durations of therapy with good initial clinical response).
TAKE HOME POINTS:
- Pyogenic liver abscesses typically occur from 1) hepatobiliary spread 2) hematogenous spread or 3) through the portal circulation.
- Pyogenic liver abscesses tend to be polymicrobial and made up of enteric GNRs and anaerobes. GPC abscesses or monomicrobial abscesses without a recent intervention should prompt evaluation for another site of infection.
- Klebsiella pneumoniae can cause primary liver abscesses in the absence of recent procedures or hepatobiliary/GI infection.
- K. pneumoniae primary liver abscess is most common in Asians.
- Davis, J & McDonald, M. Pyogenic liver abscesses. Bloom, A (ed.) in UpToDate, Inc. Maltham, MA. Accessed on November 19, 2017.
- Yu, WL & Chuang, YC. Invasive liver abscess syndrome caused by Klebsiella pneumoniae. Bloom, Allyson (ed.) in UpToDate, Inc. Maltham, MA. Accessed on November 19, 2017.