Liver Abscess: Causes, Treatment, And Outlook

A liver abscess can cause swelling and pain in the upper right of the abdomen. It is crucial to diagnose and treat a liver abscess early to avoid it rupturing. Without treatment, a liver abscess can be fatal.

A pyogenic liver abscess is a sac of pus that develops in the liver, usually due to a bacterial infection.

“Pyogenic,” means filled with pus. Pus is made of blood and dead cells and usually forms in response to an infection. Bacterial infections typically spread through the bloodstream from another body part, such as the bile ducts.

The liver has four lobes:

• right
• left
• caudate
• quadrate

In around 50% of cases, liver abscesses occur in the liver’s right lobe, which is the largest lobe with the most blood supply.

Liver abscesses are uncommon, affecting only 2.3 out of every 100,000 people. They are more common in males than females. People aged 40 to 60 years are the most likely to develop a liver abscess due to an infection rather than an injury.

The most common cause of a pyogenic liver abscess is an infection in the blood, bile ducts, or abdomen, such as appendicitis, diverticulitis, or a perforated bowel. Infections can travel to the liver from other body parts through the bloodstream.

Bacteria that are most commonly present in liver abscesses are:

• E. coli
• Klebsiella
• Streptococcus
• Staphylococcus

Conditions affecting the biliary tract, such as biliary stones, cancer, and congenital abnormalities, are a common cause of pyogenic liver abscesses. The biliary tract consists of the liver, gallbladder, and bile ducts.

Injury to the liver can also cause bacterial liver abscesses. Injury may be due to surgery or procedures such as an endoscopy.

A blow to the abdomen can cause hemorrhage, tissue death, and bile leakage, which can all lead to abscess formation.

A doctor will first ask about a person’s symptoms and whether they have had any recent infections or treatment. They will then perform a physical examination to look for signs of an enlarged liver or jaundice, which may involve looking at a person’s eyes.

A doctor will likely order blood tests, including a complete blood count and tests for specific biomarkers of liver injury. A laboratory will also analyze a person’s blood for the presence of bacteria, which can help determine which antibiotics to use.

Imaging scans, such as an abdominal ultrasound, CT scan, or MRI can help locate and measure the abscess. It may be necessary to extract fluid from the abscess to confirm the diagnosis and the bacteria involved.

If doctors suspect a liver abscess, they will work quickly to identify the cause and begin treatment to help prevent complications.

Treatment for a pyogenic liver abscess begins with antibiotics. Doctors may prescribe antibiotics in pill or liquid form, but sometimes a hospital stay is necessary so a person can receive antibiotics through a vein (intravenously).

Antibiotic therapy can last several weeks and a person may need repeated scanning to monitor changes in the abscess. Abscesses under 3 centimeters in size are generally suitable for antibiotic therapy alone.

However, antibiotics may not be enough to clear the abscess, and it may be necessary to drain it. Drainage methods include:

• Aspiration: This involves inserting a syringe needle through the skin into the abscess and drawing out the pus.
• Catheter drainage: Another method is to guide a thin wire into the abscess using ultrasound or CT imagery, place a catheter (flexible tube) over the wire, and drain the abscess gradually over 5 to 7 days.
• Surgical drainage: This method is typically necessary when other drainage attempts have been ineffective or the abscess is difficult to access. Surgeons cut into the abdomen to reach the liver and drain it. This may also allow them to identify the source of infection and any other issues.

After treatment, follow-up imaging tests, such as ultrasound, CT, or MRI scans, may be necessary to check the treatment has worked.

Treatment for a liver abscess can carry the following risks:

• internal bleeding
• a second infection
• failure to remove the abscess

People may need further treatment to address these issues.

If a pyogenic liver abscess ruptures, pus can leak into other areas of the body and cause life threatening complications, such as:

• sepsis, a severe blood infection, which can be fatal
• peritonitis, which is inflammation of the lining of the abdomen
• empyema, which are pockets of pus that collect inside a cavity in the body, typically between the lungs and chest wall
• compression of blood vessels, reducing blood flow
• encephalopathy, which can cause changes in brain function
• vascular thrombosis (a clot in a blood vessel)
• acute kidney injury
• acute respiratory distress syndrome
• endophthalmitis, a serious infection of the eye that can cause vision loss
• abscesses in other organs
• widespread infection and inflammation

The outlook for a person with a liver abscess is much better than it used to be, and they rarely cause long term damage. However, a liver abscess and treatment for this condition can leave scars on the liver that may be visible on imaging scans for years.

After treating a person’s liver abscess, a doctor may recommend regular blood tests to see how their liver is functioning. If a person experiences any symptoms of a new abscess, they will need to speak with a doctor.

Around 2.5% to 19% of people who have to stay in hospital with a liver abscess die.

The outlook may be less positive for people in the following groups:

• older adults
• people who spend time in the ICU
• people who have:

A pyogenic liver abscess is a pocket of pus in the liver that often forms due to an infection spreading from elsewhere in the body. It can cause pain in the upper right of the abdomen, fever, dark urine, and other symptoms.

Early diagnosis and treatment is essential to avoid the abscess rupturing, which can cause life threatening complications. Antibiotics may be enough to treat small abscesses. However, many require drainage.

Most people who receive treatment for a liver abscess recover without long term consequences. They will need regular monitoring to check their liver is functioning properly.