Hepatic abscess can be caused by various bacteria or amoebic protozoa. The abscess may be single or multiple. The main routes of bacterial invasion include: (1) hematogenous infection, where bacteria enter the liver through the bloodstream during bacteremia or sepsis; (2) invasion through the biliary system; (3) during the neonatal period, bacteria can enter the liver via the umbilical vein; (4) direct spread from inflammation in adjacent organs, such as subphrenic abscess. Common bacteria include Staphylococcus aureus and Streptococcus.

bubble_chart Clinical Manifestations

1. Irregular fever. Bacterial liver abscesses have a higher fever, and most patients are accompanied by shivering.
2. Persistent pain in the liver area. Liver enlargement and tenderness are more obvious, with percussion pain in the liver area. Abscesses at the top of the liver can cause cough and difficulty breathing. Multiple abscesses may be accompanied by jaundice.

bubble_chart Auxiliary Examination

1. Blood Picture The total white blood cell count increases, reaching 20.0×10⁹/L to 30.0×10⁹/L, with elevated neutrophils. 2. Stool Examination In cases caused by amoebae, trophozoites and cysts may be found in some samples. 3. X-ray Examination For abscesses in the upper part of the liver, elevation and restricted movement of the right diaphragm may be observed. 4. Ultrasonography Larger liver abscesses may show fluid levels, while smaller abscesses may yield negative results. This method can determine the size, location, number, and depth of the abscesses. 5. Liver Puncture Under ultrasound guidance, liver puncture and pus aspiration can be performed to identify the nature of the abscess. The pus from amoebic liver abscesses is typically brownish and may contain amoebic protozoa.

Treatment of

(I) General Treatment Bed rest, enhanced nutrition, and supplementation of calories, proteins, and vitamins are recommended. Blood transfusion may be administered in small amounts when necessary. (II) Bacterial Liver Abscess 1. Antibiotics For cases where bacterial diagnosis is unclear, a combination of two antibiotics may be used. If bacterial culture is positive, antibiotics should be selected based on drug sensitivity results. The antibiotic course should continue for 2–3 weeks after fever subsides. 2. Drainage (expelling pus) Percutaneous drainage is generally feasible, especially for single abscesses. The puncture site can be chosen at the most distended and tender intercostal space or based on ultrasound localization. If the pus is viscous, saline can be injected for irrigation to facilitate expelling pus. If drainage is ineffective or inadequate, incision and drainage may be performed. (III) Amebic Liver Abscess 1. Anti-amebic Drugs Metronidazole (Flagyl) dose: 35–50 mg/(kg·d), divided into three oral doses per day for 10 days as one course. Alternatively, chloroquine may be used, dose: 10 mg/kg per dose, twice daily for 2 days, then reduced to once daily for over 2 weeks. 2. Expelling pus (drainage) The method is the same as above.

bubble_chart Differentiation

Differentiation between Bacterial Liver Abscess and Amebic Liver Abscess

Differentiation between Bacterial Liver Abscess and Amebic Liver Abscess Bacterial Liver Abscess Amebic Liver Abscess Medical History Possible history of bacteremia, sepsis, or biliary tract infection Possible history of amebic dysentery Onset Acute onset with obvious toxic symptoms Gradual onset with milder toxic symptoms Liver Abscesses may be multiple or solitary; degree of hepatomegaly varies Abscess is mostly solitary with localized liver protrusion White Blood Cells Increased total count and neutrophils No significant increase Blood Culture May be positive Negative Liver Aspiration Variable pus volume, yellow or yellowish-white; bacterial culture may be positive Large volume of pus, brownish; may find Entamoeba histolytica Treatment Effective with antibiotics Effective with emetine or chloroquine