Abdominal abscesses: what is it, causes, symptoms, treatment, prognosis

What is an abdominal abscess?

An abscess is a pus-filled pocket that usually results from a bacterial infection.

• Most people have persistent abdominal pain and fever.
• An abscess can be distinguished from other problems with computed tomography or other imaging tests.
• Treatment includes drainage of pus from the abscess and antibiotics.

Abdominal abscesses can occur under the diaphragm, in the mid-abdomen, in the pelvic region, or behind the peritoneum. Abscesses can also occur around any abdominal organs, such as the kidneys, spleen, pancreas or liver, or in these organs, or in the prostate gland. Untreated abscesses can grow and damage nearby blood vessels and organs. Sometimes bacteria enter the bloodstream (sepsis) and spread to distant organs and tissues. This spread can be fatal.

Causes

Sometimes abdominal abscesses are caused by intestinal perforation due to cancer, ulcers, or lesions.

More common causes include spread of infection or inflammation caused by diseases such as 

appendicitis, diverticulitis, Crohn's disease, pancreatitis or pelvic inflammatory disease.

Sometimes an abscess occurs after an abdominal injury or after abdominal surgery.

Signs and symptoms

The specific symptoms of abdominal abscesses depend on the location of the abscess, but most people experience constant discomfort or pain, a general painful condition (malaise) and often have increased temperature. Other symptoms include nausea, loss of appetite and weight loss.

Subphrenic abscess can occur when infected fluid, such as from a ruptured appendix, flows upward under pressure of the abdominal organs and as a result of the vacuum that occurs when the diaphragm moves during breathing. Symptoms may include coughing, painful breathing, chest pain, and pain in one shoulder. In this case, pain felt in one shoulder is an example of radiating pain (pain felt in one area of ​​the body that does not correctly reflect the location of the problem). Radiating pain occurs when the shoulder and diaphragm share the same nerves, and the brain misidentifies the source of the pain.

Sources abscesses in the middle of the abdomen there may be a ruptured appendix, a ruptured intestine, inflammatory bowel disease, diverticulosis, or an abdominal injury. Pain is usually felt in the area of ​​the abscess in the abdomen.

An abscess in the lower abdomen may radiate pain in the thigh or the area around the rectum (called the perirectal fossa).

Intra-pelvic abscesses can develop as a result of the same disorders that cause abscesses in the mid-abdominal cavity, or as a result of gynecological infections. Symptoms may include abdominal pain, diarrheacaused by intestinal irritation, and urgent or frequent urge to urinate caused by irritation of the bladder.

Abscesses behind the abdomen (called retroperitoneal abscesses) are located behind the peritoneum, the membrane that lines the abdomen and organs. Similar causes of abscesses in the abdomen include inflammation and infection of the appendix (appendicitis) and the pancreas (pancreatitis). Pain, usually in the lower back, gets worse when a person flexes their leg at the hip joint.

Pancreatic abscessesalthough rare, they usually develop after an attack of acute pancreatitis. Symptoms such as fever, abdominal pain, nausea, and vomiting often begin to appear a week or more after a person has recovered from pancreatitis.

Liver abscesses can be caused by bacteria or amoebae (unicellular parasites). Bacteria can enter the liver from an infected gallbladder, a penetrating or blind wound, an infection in the abdomen (such as a nearby abscess), or an infection from the bloodstream from other parts of the body. Amoeba (microscopic parasites) from the focus of intestinal infection enter the liver through the blood vessels. Symptoms of liver abscesses include loss of appetite, nausea, and fever. The patient may or may not have abdominal pain.

Abscesses in the spleen are caused by an infection through the bloodstream to the spleen, an injury to the spleen, or an infection spread from a nearby abscess, such as a subphrenic abscess. Pain can occur on the left side of the abdomen, back, or left shoulder.

Diagnostics

Diagnostics include:

• imaging examinations;
• needle aspiration.

Doctors can easily be mistaken when diagnosing an abscess, because the first symptoms that the disease causes, usually vague and mild, and can be mistaken for less severe and more common Problems.

If doctors suspect a patient has an abscess, they usually do a computed tomography (CT) scan of the abdomen and pelvis, or sometimes ultrasound (ultrasonography), abdominal and chest X-rays, or magnetic resonance imaging tomography (MRI). These tests can help distinguish an abscess from other problems and can help determine the cause, size, and location of the abscess.

To make an accurate diagnosis and treat an abscess, doctors sometimes insert a needle through the skin to take a sample of pus from the abscess (puncture biopsy) and place a drain. Doctors use ultrasound or CT to visualize the needle insertion process. After that, a laboratory study of a fluid sample is carried out to identify the infectious microorganism so that the most effective antibiotic can be selected.

Sometimes a radionuclide scan is done to detect abscesses. In a scan, a radionuclide is used to mark a substance that accumulates in a specific part of the body. Different substances are used depending on the part of the body being examined.

Treatment

Treatment includes:

• drainage of pus;
• antibiotics.

Pus must be drained from almost all abdominal abscesses through surgery or with a needle and small flexible tube (catheter). An ultrasound or CT scan is used to visualize the insertion of the needle and catheter. Once the doctor is satisfied that the needle and catheter have reached the abscess, the needle is removed and the catheter is left in place. Pus is usually released through the catheter over a period of several days to weeks.

Antibiotics are usually used in addition to drainage to keep the infection from spreading and eliminate the infection completely. With the help of laboratory analysis of pus, an infectious microorganism is identified so that the most effective antibiotic can be selected. Without drainage, antibiotics rarely heal abscesses.

If the needle and catheter cannot safely reach the abscess, surgical drainage may be required. After drainage of the abscess, the source of infection is surgically treated. For example, if an abscess is caused by a perforation (hole) in the intestine, doctors usually remove that part of the intestine.

It is important to provide proper nutrition. If patients are unable to eat due to an abscess or the cause of the abscess, they may Receive food through a tube (tube feeding) or through a vein (parenteral feeding).

Forecast

The prognosis of patients with abdominal abscess before the era of computed tomography was very poor. Today, when CT scans have become available, the diagnosis is made much earlier, and in fact, CT-guided drainage has helped reduce morbidity in many cases. However, if a peritoneal abscess is misdiagnosed and untreated, mortality is very high. Risk factors that increase mortality and morbidity include the following:

• elderly age;
• multiple organ failure;
• several recent operations;
• complex abscess;
• delay in diagnosis.

Even so, abdominal abscesses can lead to death in about 10-40% of people.

Complications

An abdominal abscess can lead to the following complications:

• multiple organ failure;
• fistula formation;
• septic shock;
• both drainage under CT and surgery can lead to bowel perforation;
• deep vein thrombosis;
• malnutrition;
• death.