Liver Abscess: Causes, Symptoms, And Treatment

Your liver plays an important role in keeping your body free from toxins. Problems with your liver can, thus, cause all kinds of issues, some of which may be life-threatening.

One of the conditions that can develop is a hepatic abscess. An abscess on your liver can be caused by a variety of things and have a number of symptoms.

What is a liver abscess?

A liver abscess is a pus-filled mass in the liver. Like abscesses elsewhere, it is typically caused by injury or infection. There are three main types of liver abscess:¹

Pyogenic liver abscess

Pyogenic means "producing pus." This type of abscess can be caused by an abdominal infection or infection in the blood or associated with biliary disease. 

Pyogenic liver abscesses can be an extremely rare complication of appendicitis, but the most common cause is leakage from the bowel traveling to the liver through the portal vein. In many cases, the infection is in the biliary tract. Most pyogenic abscesses show multiple microbes present.

Amoebic liver abscess

Amoebic or amebic liver abscess is caused by the parasite Entamoeba histolytica and is a complication of amebiasis. You get amebiasis from eating food or drinking water contaminated with human feces. 

Symptoms of amebiasis can be mild or severe, with only 10–20% of infected people becoming sick. They include loose feces, stomach pain, or cramping. Amoebic dysentery, a severe form, is associated with stomach pain, bloody stools, and fever. Most people with amebiasis only get mildly sick, if at all, and put it down to "traveler's diarrhea."

Thankfully, liver abscesses from this cause are rare. However, the amebic liver abscess is the most common extraintestinal manifestation of amebiasis.

Amoebic liver abscess is most commonly found in tropical areas with poor sanitation. In developed countries, it is most often found in people who have recently traveled to a tropical region. 

Factors predisposing to the progression to an amebic liver abscess are not fully understood, and sexual oral-anal contact may also account for amebic infection and subsequent progression to a liver abscess.

Invasive liver abscess due to Klebsiella pneumoniae

Although it mainly causes pneumonia, K. pneumoniae can also lead to infection in various body sites, especially in those with impaired defenses, such as individuals living with diabetes, alcoholism, or COPD. 

Unlike a pyogenic abscess, Klebsiella pneumoniae liver abscess (KLA) is mono-bacterial and occurs in the absence of predisposing intra-abdominal factors such as hepatobiliary disease or a history of intraabdominal surgery/trauma.

Traumatic liver abscess

Another cause of a liver abscess is trauma — usually, a blunt force blows to the abdomen, but also potentially as a result of gunshot wounds. It is a rare complication and typically involves infection in a part of the liver that was bruised or contused.

Liver abscess due to fungal infections

Very rarely, a liver abscess can be caused by a fungal infection. These can be particularly difficult to treat and often result in serious complications. However, this is very rare.

Common symptoms of liver abscess

A liver abscess typically causes the following symptoms:

• Pain in the right upper abdomen or lower right chest (Less commonly, pain can spread throughout the abdomen.)

• Fever or chills

• Loss of appetite

• Nausea/Vomiting/Diarrhea

• Jaundice (yellowing of the skin, mucous membranes, or eyes, a common indication of something wrong with the liver)

• Referred pain in the right shoulder

In most cases, an amebic liver abscess can be primarily suspected if you have recently traveled to a tropical country — however, you can also get this without traveling. You should be careful what you eat and drink in the tropics. Avoid drinking unfiltered water and eating uncooked vegetables or unpeeled fruit.

Can liver abscesses be life-threatening?

Yes. All types of liver abscesses can be life-threatening if not treated. Pyogenic liver abscesses can lead to sepsis. Amebic liver abscesses can rupture and spread the infection to other organs, resulting in death. However, liver abscesses are treatable.

What are the risk factors for developing a liver abscess?

The risk factors for liver abscesses depend on the type to some degree, but some risk factors include:

• Diabetes

• Cirrhosis of the liver, which is often but not always associated with excessive alcohol consumption

• Immunocompromised state

• Male sex

• Advanced age

• Proton pump inhibitor use

Additionally, recent travel to or residence in a tropical country is a risk factor for amebic liver abscess.

Most liver abscesses cannot be prevented, but you can protect your liver by moderating your alcohol consumption. Avoid consuming more than two drinks a day for men and one for women, and avoid binge drinking, defined as four or more drinks in a single session.

If you travel overseas, avoid ice cubes, unfiltered water, unwashed fresh fruit or vegetables, raw milk or cheese, and anything sold by street vendors unless prepackaged. This can also prevent ruining your holiday as it protects you from other infections that can cause "travelers' diarrhea," among other fecal-oral spread infections.

How is a liver abscess diagnosed?

If you have the symptoms of a liver abscess, your doctor will do a full medical history, review symptoms, and order several tests. For most liver abscesses, this means carrying out a CT scan or ultrasound of the abdomen to look for the physical signs of an abscess. They may also order a blood culture to look for an infection in your blood and a complete blood count.

Liver function tests and potentially a biopsy may also be on the table. Liver enzymes are usually elevated if you have an injury to your liver. Alkaline phosphatase is also typically elevated.

X-rays are typically not used to diagnose liver abscesses as they’re not sensitive or specific enough, and there are much better imaging tools available. The first test is typically an ultrasound. The liver abscess may be aspirated or drained, which may allow your doctor to determine what organism is infecting your liver.

As liver abscesses are serious, your doctor will want to do tests quickly. If the amebic liver abscess is suspected they may also test your blood or stool for amebiasis.

If you have recently traveled to a tropical region, tell your doctor, and tell them honestly if you ate or drank anything that might have led to exposure, such as street food.

Liver abscess treatment

Liver abscesses are serious if not treated. Thankfully, they are treatable. Some treatment options include:

1. Draining the abscess by placing a tube through the skin into the liver: This allows pus and gas to escape and shrinks the size of the abscess. Very small abscesses can sometimes be drained using needle aspiration alone.

2. Antibiotics: Usually, you will receive a four to six-week course, depending on the cause. A biopsy/culture or blood test may be used to determine which bacteria are causing the infection and choose the appropriate antibiotic. For amebic liver abscesses, metronidazole or tinidazole is typically recommended. If the organism is unknown, broad-spectrum antibiotic treatment will be used. This usually means IV antibiotics for the first part of treatment, which may require hospitalization. The second part will be with oral antibiotics. As with all antibiotic courses, you should always complete the course, even if you think you are better. Your doctor may prescribe multiple antibiotics.

3. Surgery to remove the abscess: This is less commonly needed but might be considered if the abscess is recurrent or not responding to antibiotics. In some cases, the abscess may be in a location that makes percutaneous drainage challenging, necessitating surgery.

If you have an amebic liver abscess, you will also be prescribed paromomycin or diloxanide, which are anti-parasitic drugs. You take these after the abscess has been treated to completely clear your intestines of the parasite and ensure that the disease does not come back.

Complications of a liver abscess

The primary complication of a liver abscess is the rupture of one. This can lead to sepsis or infection of other organs, which can be life-threatening. It is very important that liver abscesses are treated promptly.

A ruptured abscess can also cause peritonitis and "walling" of the area, which results in persistent pain.

In some cases, complications can happen after drainage, which can cause infection, abscesses in the abdomen, or recurring liver abscesses. Your doctor will want to do an extensive follow-up to watch for symptoms of these issues and monitor your liver and renal function.

In most cases, however, people who are properly treated fully recover. Recurrent abscesses happen, but there are a relatively small number of cases.

When to see a doctor

You should see a doctor if you have any of the above mentioned symptoms. Liver abscesses are rare but serious. You should also see a doctor if you have these symptoms and have recently traveled to a tropical country where you might have been exposed to Entamoeba histolytica.

It's worth talking to a doctor if you have traveled and have symptoms of amebiasis, even if they are mild, or if you know you have been exposed. Your doctor can prevent complications by treating you with antibiotics.

There is no way to treat a liver abscess at home. You must seek medical attention.

The lowdown

Liver abscesses are most often caused by a hepatobiliary disease or transported through the portal vein from the bowel. They can sometimes happen after an accident or a blow. Some liver abscesses are caused by a tropical parasite, which is typically found in people who live in or recently traveled to tropical areas such as Africa and Southeast Asia.

In most cases, liver abscesses are treatable, but without treatment, they can be life-threatening. It's important to see your doctor immediately if you have symptoms of a liver abscess.