What is liver abscess?

Updated June 2018

The liver is the organ most susceptible to the formation of abscesses, which can be solitary or multiple, and which can arise due to the spread of bacteria through the blood or the local spread of foci of infection in the peritoneal cavity, close to the liver, as is the case with appendicitis, diseases associated with the biliary tract or pylephlebitis, for example.

Furthermore, liver abscess is a pathology that can also be caused by protozoa, known as amoebic liver abscess.

Treatment depends on the organism causing the infection but generally consists of administering antibiotics, draining the abscess or, in more serious cases, surgery may be recommended.

What are the signs and symptoms?

Signs and symptoms that usually occur in people who have a liver abscess are fever and in some people, especially those with disease associated with the biliary tract, they may present signs and symptoms located in the upper right quadrant, such as abdominal pain.

In addition, chills, anorexia, weight loss, nausea and vomiting may also occur.

However, only about half of people with liver abscesses have an enlarged liver, tenderness in the right upper quadrant, or jaundice, meaning many people have no symptoms that would direct attention to the liver. Fever of unknown origin may be the only manifestation of a liver abscess, especially in the elderly.

Possible causes

Liver abscesses can be caused by different microorganisms, such as bacteria or even fungi, which can arise due to the spread of bacteria through the blood or the local spread of foci of infection in the peritoneal cavity, near the liver, as is the case with appendicitis, diseases associated with the biliary tract or pylephlebitis, for example. Learn more about appendicitis and how to identify it .

Additionally, liver abscesses can also be amoebic:

Amoebic liver abscess

Amebic liver abscess is an infection of the liver by protozoa. The disease begins when the protozoa  E. histolytica penetrate the intestinal mucosa, cross the portal circulation and reach the liver. Most patients with this disease do not present signs and symptoms or the presence of the protozoa in the stool.

The disease can appear months to years after traveling or living in an endemic area, so it is important to carefully review the travel history to make a diagnosis. The most common symptoms are right upper quadrant pain, fever, and liver tenderness.

The most common laboratory findings are leukocytosis, elevated alkaline phosphatase, mild anemia, and an elevated erythrocyte sedimentation rate.

What does the diagnosis consist of?

The single most reliable laboratory finding is an elevation in serum alkaline phosphatase levels, which are usually high in people with liver abscess. In about half of cases, there may also be an increase in blood bilirubin and aspartate aminotransferase, leukocytosis, anemia, and hypoalbuminemia.

Imaging tests are usually the most reliable in diagnosing this disease, such as ultrasound, computed tomography, scintigraphy with leukocytes labeled with indium or gallium, and magnetic resonance imaging. A chest X-ray may also be performed.

Diagnosis of amebic liver abscess is based on detection by ultrasound or computed tomography of one or more space-occupying lesions in the liver and a positive serologic test for antibodies to  E. histolytica antigens.

How is the treatment done?

Treatment can be done through percutaneous drainage, with a catheter with side holes kept in place. In addition, antibiotics specific to the microorganism responsible for the infection can also be used, after a sample of the abscess has been removed. In cases where the abscess is drained, longer antibiotic treatment is necessary.

If the infection is caused by Candida, treatment usually consists of administering amphotericin, followed by treatment with fluconazole. In some cases, treatment with fluconazole alone may be used, particularly in clinically stable individuals whose isolated microorganism is susceptible to this drug.

Medications such as nitroimidazole, tinidazole, and metronidazole can be used to treat an amoebic liver abscess. To date, this protozoan has not shown resistance to any of these medications. Drainage of amoebic liver abscesses is rarely necessary.