Liver Abscess

What is a liver abscess?

Abscesses occur when areas in the body collect pus and form a mass. The mass can be solitary or multiple and develop anywhere in the body, such as in the liver. Liver abscesses are considered rare, with an occurrence rate of 2% (at most) in every 100,000 people.

The most common liver abscesses can be classified into two main types based on their underlying cause and characteristics: pyogenic and amoebic.

• Amoebic liver abscess:  an amoebic liver abscess is caused by the parasite Entamoeba histolytica. The parasite usually takes its initial root in the intestine and can travel to the liver through the bloodstream, resulting in a liver abscess.
• Pyogenic liver abscess: a pyogenic liver abscess occurs due to a bacterial infection. It occurs when infections spread directly from nearby structures, like the intestines or bile-draining tubes. Additionally, the infection can travel to distant parts of the body through the bloodstream.

Other less common types of liver abscesses include:

• Traumatic liver abscess: a traumatic liver abscess results from trauma or injury to the liver, such as penetrating abdominal injuries or surgical complications. Bacteria from the gastrointestinal tract or bloodstream can enter the liver tissue and cause an infection.
• Metastatic liver abscess: metastatic liver abscesses occur when cancer cells from primary tumours elsewhere in the body spread to the liver. Abscesses form when secondary infection occurs in the secondary liver tumour. 

What causes liver abscesses?

Liver abscesses can develop as a result of various factors, including:

• Bacterial infection: pyogenic liver abscesses are commonly caused by bacteria such as Escherichia coli, Klebsiella pneumoniae, and Streptococcus species. These bacteria can enter the liver through the bloodstream, bile ducts (when there is infection), or from nearby organs.
• Amoebic infection: amoebic liver abscesses are caused by the parasite Entamoeba histolytica, which is transmitted through contaminated food or water. The parasite invades the liver tissue, leading to the formation of abscesses.
• Trauma or injury: liver abscesses can develop following trauma to the abdomen, such as a penetrating injury or surgery. Bacteria from the gastrointestinal tract or bloodstream can enter the liver and cause infection.

What are the symptoms of a liver abscess?

The symptoms of a liver abscess vary based on the underlying cause and size. Common symptoms of a liver abscess may include:

• Intense pain in the upper right abdomen 
• Fever and chills
• Nausea and vomiting
• Unexplained weight loss
• Jaundice
• Loss of appetite.
• Malaise and lethargy
• Persistent hiccups
• Dark-coloured urine
• Clay- or grey-coloured stools

Are liver abscesses painful?

Yes, liver abscesses can be painful. While the pain is typically located in the upper right quadrant of the abdomen, its intensity varies from mild to severe. A few factors, such as the size of the abscess, its location, and the patient’s pain tolerance, determine the intensity of the pain.

However, it should be noted that abdominal pain is a universal symptom. Just because you are experiencing abdominal pain does not immediately confirm the presence of an abscess in your liver. That is why it is best to seek a medical consult, should symptoms persist, and receive a proper diagnosis.

Who is at risk of developing liver abscess?

Although liver abscesses are considered uncommon, there are a few risks associated with the development of liver abscesses. Risk factors for developing liver abscesses include: 

• History of abdominal trauma or surgery: individuals with a history of recent abdominal trauma or surgery are at an increased risk of developing traumatic liver abscesses.
• Compromised immune system: diseases such as Aids/HIV and diabetes can compromise the immune system and increase an individual’s risk of developing liver abscesses.
• Age: liver abscesses are more commonly found in elderly individuals. 
• Malnutrition: poor nutrition can weaken the immune system, making individuals more susceptible to infections, including those that can lead to liver abscesses.
• Diabetes: Diabetic is associated with several metabolic and immune system dysfunctions that can increase the risk of infections, including liver abscesses.
• Biliary tract/gallbladder infections: diseases in the biliary system, such as cholecystitis (inflammation of the gallbladder) or cholangitis (inflammation of the bile ducts), can lead to liver abscesses.

How are liver abscesses diagnosed?

Diagnosing a liver abscess is a relatively straightforward procedure which involves a combination of the following:

• Medical history and physical examination: your specialist will inquire about your medical history and the onset of symptoms and conduct a physical exam to check for liver tenderness.
• Blood tests: to check for abnormalities, various blood tests, such as liver function tests and complete blood counts, will be conducted.
• Imaging tests: imaging tests will be conducted to identify the size, location, and characteristics of the liver abscess. Imaging tests include an abdominal ultrasound, computed tomography (CT) scans, and magnetic resonance imaging (MRI). 

What are the treatment options for liver abscesses in Singapore?

The treatment of liver abscesses varies based on severity, type of abscess, location, general health, and cause of the abscess. Typical treatment for liver abscesses include:

• Antibiotics: most liver abscesses are caused by a bacterial infection, so antibiotics are the most common treatment. 
• Abscess drainage: liver abscesses are typically drained in two ways: percutaneous drainage and surgical drainage. Percutaneous drainage is minimally invasive and conducted with ultrasound or CT scan guidance. Surgical drainage involves open surgery or laparoscopic drainage and is usually necessary if percutaneous drainage is unsuccessful or the location is not suitable for percutaneous procedures.

Frequently asked questions

What is the main cause of liver abscesses?

A bacterial infection is the most common cause of liver abscesses. 

What is the survival rate for liver abscesses?

The survival rate for liver abscesses can vary depending on various factors, including the underlying cause, the promptness of diagnosis and treatment, the size and location of the abscess, the presence of complications, and the patient's overall health. With timely and appropriate medical intervention, the prognosis for liver abscesses is favourable, and most patients recover fully.

Is there anything that I can do to prevent liver abscess?

Avoiding liver abscesses may not always be possible. However, there are steps that you can take to reduce the risk. This includes:

• Avoiding contaminated food or water.
• Managing underlying health conditions that risk liver abscesses.

Are there any complications of liver abscesses?

Yes, there are complications associated with a liver abscess, especially when it ruptures. A ruptured abscess is considered critical as it can lead to infections or sepsis. Abscesses associated with generalised severe sepsis may have seeding of an abscess to the lungs, brain, or even bones.