bubble_chart Overview

Liver abscess can be caused by infection with Entamoeba histolytica or bacteria. Amebic liver abscess is closely related to amebic colitis, and most abscesses are solitary. In bacterial liver abscess, bacteria can invade through septicemia, direct spread from intra-abdominal infections, or via umbilical vein and portal vein from umbilical infections. Biliary ascariasis can also be a predisposing factor for bacterial liver abscess. Common bacteria include Staphylococcus aureus and Streptococcus.

bubble_chart Diagnosis

Medical history and symptoms

Irregular septic fever, especially more pronounced in bacterial liver abscess. Persistent pain in the liver area, aggravated by deep breathing and body movement. Depending on the location of the abscess, corresponding respiratory or abdominal symptoms may occur. A history of diarrhea is often present. Therefore, a detailed inquiry into past medical history is necessary, particularly regarding fever, diarrhea history, the onset and progression of the illness, the location of abdominal pain, accompanying symptoms, diagnostic and treatment processes, and their efficacy.

Physical examination findings

The liver is often enlarged (liver tenderness is related to the abscess location), with localized edema and significant tenderness at the intercostal space corresponding to the abscess site. Some patients may develop jaundice. If the abscess ruptures into the thoracic cavity, empyema or lung abscess may occur, or if it ruptures into the abdominal cavity, peritonitis may develop.

Auxiliary examinations

Elevated white blood cell and neutrophil counts, especially in bacterial liver abscess, which can reach 20–30×10⁹

/L. In amoebic liver abscess, amoebic cysts or trophozoites may occasionally be found in the stool. Enzyme-linked immunosorbent assay (ELISA) to detect anti-amoebic antibodies in the blood can help determine the nature of the abscess, with a positive rate of 85–95%. Liver puncture in amoebic liver abscess may yield chocolate-colored pus; in bacterial abscess, yellowish-green or yellowish-white pus may be obtained, and culture can identify the causative bacteria. The pus should be tested for AFP to rule out liquefaction of liver cancer. The Casoni test can exclude hepatic echinococcosis.

X-ray examination may show elevation and limited mobility of the right diaphragm, and sometimes pleural reaction or effusion.

B-mode ultrasound examination is highly valuable for diagnosing and locating the abscess. In the early stage when the abscess is not fully liquefied, differentiation from liver cancer is necessary.

CT examination may reveal single or multiple round or oval low-density areas with clear boundaries and uneven density, possibly containing gas bubbles. Enhanced scanning shows no change in the density of the abscess cavity, but the cavity wall exhibits irregularly increased density enhancement, known as the "ring moon sign" or "halo sign."

bubble_chart Treatment Measures

The diagnosis of liver abscess is clear, and hospitalization is required for different treatments based on its nature. For mild amebic liver abscess, outpatient treatment with metronidazole or tinidazole 0.4–0.8g orally three times a day for 5–10 days, or intravenous infusion of 1.5–2.0g per day, may be considered. It is contraindicated in breastfeeding women, pregnant women in the first trimester, and those with central nervous system diseases. Chloroquine: adults should take 1g per day for the first two days, then 0.5g per day from the third day onward, with a treatment course of 2–3 weeks. Bacterial liver abscess requires hospitalization for treatment.