Amoebic Liver Abscess

Amoebic Liver Abscess
Body Parts: Abdomen
Medical Subjects: Liver And Gallbladder

What Is Amoebic Liver Abscess

Amoeba liver abscess is the most common complication of Miba enteropathy. Its main clinical manifestations are long-term fever, chest pain in upper right abdomen or lower right abdomen, systemic consumption, swelling and tenderness of liver, and leukocytosis, which easily lead to chest complications.


What Is The Cause Of Amoebic Liver Abscess

Amoeba liver abscess is caused by amoeba histolytica. Some developed during amoebic dysentery, some occurred several weeks or months after dysentery, and some lasted for twenty or thirty years. When people swallow food or drinking water contaminated by amoeba cysts and digest them by gastric juice, protozoa are released in the intestines and multiply, invading the colon mucosa and forming ulcers, which are common in cecum and ascending colon. The amoeba protozoa parasitic on the colonic mucosa secrete histolytic enzyme, and after digesting and dissolving the small veins on the intestinal wall, the protozoa invade the veins and enter the liver with the blood flow of portal vein. Some living protozoa propagate in the liver and dissolve the liver tissue to form abscess.


What Symptom Does Amoebic Liver Abscess Have

The basic points of clinical diagnosis of liver swelling are: ① Upper right abdominal pain, fever, liver enlargement and tenderness. ② X-ray examination showed that the right diaphragm was elevated and its motion was weakened. ③ Ultrasonography showed the level segment of liver fluid. If typical pus is obtained by liver puncture, or amoeba trophozoites are found in the pus, or it has a good effect on specific anti-amoeba drugs, it can be diagnosed as amoeba liver abscess.

It is related to the course of disease, the location of abscess and complications. Most of them have symptoms such as irregular fever and night sweat. Fever is mostly intermittent or relaxation. When there are complications, the body temperature often reaches above 39℃, and it can show bimodal fever. Most of the body temperature rises in the afternoon, reaches its peak in the evening, and is accompanied by profuse sweating when the temperature recedes at night. The middle layer often has symptoms such as loss of appetite, abdominal distension, nausea, vomiting, diarrhea, dysentery, etc. The pain in the liver area is an important symptom of the disease, showing persistent dull pain, which increases when taking deep breath and changing body position, and the pain is often more obvious at night. Abscess at the top of the right lobe can stimulate the right diaphragm and cause pain in the right shoulder, or press the right lower lung to cause pneumonia or pleurisy signs, such as shortness of breath, cough, and forced right lower lung to cause pneumonia or pleurisy signs, such as shortness of breath, cough, elevated voiced boundary at the bottom of the lung, wet rale smell at the bottom of the lung, pleural friction sound in the internal organs, etc. Abscess located in the lower part of the liver can cause right upper abdominal pain and right low back pain. Some patients have right lower chest or right upper abdomen full or palpable lump with tenderness. The left lobe liver abscess accounts for about 10%. Patients have middle upper abdominal pain or left upper abdominal pain, which radiates to the left shoulder, and the liver under xiphoid process is swollen or middle and left upper abdomen is full, tenderness, muscle tension and percussion pain in the liver area. The liver is often diffusely enlarged, with obvious localized tenderness and percussion pain at the lesion site, and the lower edge of the liver is blunt, full and hard. Some patients have local fluctuation in liver area. Jaundice is rare and mild, and the incidence of jaundice in multiple abscesses is high.

Chronic cases are in a state of exhaustion, wasting, anemia, nutritional edema, and fever is not obvious. Some patients with advanced stage have liver enlargement and local swelling, which are easily mistaken for liver cancer.


How To Check For Amoebic Liver Abscess

1. Hemogram Examination: The total number of white blood cells increased moderately in acute stage, and neutrophils were about 80%, especially when there was secondary infection. When the course of disease is long, the white blood cell count is mostly close to normal or decreased, anemia is obvious, and ESR increases rapidly.

2. Stool Examination: Amoeba histolytica can be found in a few patients.

3. Liver Function examination: Alkaline phosphatase is the most common, cholesterol and albumin are mostly decreased, and other indexes are basically normal.

4. Serological Examination: The positive rate of antibody can reach more than 90% with amebic enteropathy. Negative patients can basically rule out this disease.

5. Liver Imaging: Ultrasonic exploration is noninvasive, accurate and convenient, and has become the basic method for diagnosing liver abscess. The location of the abscess shows a level segment with the same size as the abscess, which may be located by puncture or surgical drainage. Repeated exploration can observe the progress of the abscess cavity. B-mode ultrasound imaging has high sensitivity, but it is difficult to distinguish it from other liquid lesions, which requires dynamic observation. CT, hepatic arteriography, radionuclide liver scanning, and nuclear magnetic resonance can all show space-occupying lesions in liver, which is helpful to distinguish amoebic liver disease from liver cancer and hepatic cyst, among which CT is particularly convenient and reliable, and those with conditions can be selected.

6. X-ray Examination: It is common that the right diaphragm is raised, the movement is limited, pleural reaction or effusion, and there is cloud shadow on the lung floor. Barium meal fluoroscopy of gastrointestinal tract in the case of liver abscess in the left lobe showed compression of gastric curvature or displacement of duodenum, and lateral radiograph showed that the anterior medial bulge of the right rib caused the disappearance of cardiac diaphragm angle or anterior diaphragm angle. Occasionally, the irregular light-transmitting liquid-gas shadow in the liver area is seen on plain film, which is quite characteristic.


How To Prevent Amoebic Liver Abscess

Pay attention to the hygiene of diet and drinking water, cultivate good personal habits, eliminate pests, do a good job in environmental hygiene and prevent diseases from entering from the mouth, which are all powerful measures to prevent infection.


How To Treat Amoebic Liver Abscess

Medical Treatment

1. Anti-Amoeba Therapy: The anti-amoeba treatment is mainly using intra-tissue amoeba killing drugs, supplemented by intestinal amoeba killing drugs for radical cure. At present, metronidazole is the first choice, with a dose of 1.2g/ day, a course of treatment of 10-30 days and a cure rate of over 90%. In patients without complications, the clinical conditions such as liver pain and fever improved obviously within 72 hours after taking the medicine, the body temperature subsided within 6-9 days, the hepatomegaly, tenderness and leukocytosis recovered about 2 weeks after treatment, and the absorption of pus cavity was as late as about 4 months. The anti-insect activity and pharmacokinetic characteristics of the second generation nitroimidazoles are the same as those of metronidazole, but the efficacy of abscess is better than that of amoebic enteropathy due to its long half-life. Short-term treatment is used in Southeast Asia, which can replace metoclopramide. A few patients with poor curative effect of Mononazole can switch to chloroquine or emetine, but it should be noted that the former has higher recurrence rate, while the latter has more cardiovascular and gastrointestinal reactions. In the later stage of treatment, a course of intestinal anti-amoeba drugs should be added routinely to eradicate the possibility of compound prescription.

2. Liver Puncture Drainage: Many liver abscesses have no need of puncture after using effective drugs in early treatment. Puncture drainage should be used for patients with appropriate drug treatment for 5-7 days, without obvious improvement in clinical conditions, or with obvious local uplift and tenderness of liver. Puncture is best performed after 2-4 days of anti-amoeba treatment. Most of the puncture sites are the 8th or 9th intercostal of the right anterior axillary line, or the 9th or 10th intercostal of the right middle fu-organ line, where the swelling and tenderness in the liver area are most obvious. It is best to carry out ultrasonic exploration. The number of punctures is silent depending on the condition, and the pus should be pumped out as far as possible every puncture. If the pus volume is over 200ml, the aspiration should be repeated 3-5 days later. Patients with large pus cavity can recover quickly by suction. In recent years, interventional therapy, with continuous closed drainage guided by a guide needle, can avoid the disadvantages of repeated puncture and secondary infection, and is used if conditions permit.

3. Antibiotic Therapy: In case of mixed infection, appropriate antibiotics should be selected for systemic application according to bacterial species.

Surgical Treatment

In general, less than 5% of intensive liver abscesses need surgical drainage. The indications are as follows: ① Anti-amoeba drug treatment and puncture drainage failure. ② Abscess is located in a special position, close to the hepatic portal, large blood vessels or too deep, which is easy to injure adjacent organs by puncture. ③ Abscess penetrated into abdominal cavity or adjacent internal organs, resulting in poor drainage. ④ There is secondary bacterial infection in abscess, which can't be controlled by drug treatment. ⑤ Multiple abscesses make puncture and drainage difficult or unsuccessful. ⑥ Left lobe liver abscess is easy to penetrate into pericardium, and puncture is easy to pollute abdominal cavity, so surgery should also be considered.


How To Differentiate Amoebic Liver Abscess

Only 40% of amoebic liver abscesses confirmed by pathology abroad were diagnosed before their death, while the clinical misdiagnosis rate in China in recent years was 17%-38.5%. This disease should be differentiated as follows.

1. Primary Liver cancer: fever, emaciation, right upper abdominal pain, hepatomegaly and other clinical manifestations are similar to amoebic liver abscess. However, the latter usually has high heat and severe liver pain, and the liver with cancer is hard and has nodules. Detection of alpha-fetoprotein, B-mode ultrasound, abdominal CT, radionuclide liver scan, selective hepatic arteriography, nuclear magnetic resonance and other examinations can make obvious diagnosis. Liver puncture and anti-amoeba drug treatment test are helpful for differentiation.

2. Bacterial liver abscess.

3. Schistosomiasis: In schistosomiasis endemic areas, liver amoebiasis is easily misdiagnosed as acute schistosomiasis. Both of them have fever, diarrhea, hepatomegaly and so on, but the latter has mild liver pain, obvious splenomegaly, and significant increase of eosinophils in hemogram. Large case incubation, sigmoidoscopy and egg soluble antigen detection are helpful to distinguish.

4. Cholecystitis: The onset of cholecystitis is acute, with paroxysmal aggravation of right upper abdominal pain and frequent history of repeated attacks. Jaundice is common and deep, hepatomegaly is insignificant, and tenderness in gallbladder area is obvious, which can be differentiated by cholecystography and duodenal drainage.


What Are The Complications Of Amoebic Liver Abscess

The main complications of amoeba liver abscess are secondary bacterial infection and abscess breakthrough to surrounding tissues. When secondary bacterial infection occurs, chills and high fever are obvious, toxemia is aggravated, and the total number of white blood cells and neutrophils are significantly increased. The pus is yellow-green or smelly, and there are a lot of pus cells in microscopic examination, but the positive rate of bacterial culture is not high. Amoeba liver abscess locusts penetrate into surrounding organs, such as empyema or lung abscess through diaphragm, pleura-lung-bronchial fistula through bronchus, pericarditis or peritonitis through pericardium or abdominal cavity, and amebiasis through stomach, large intestine, inferior vena cava, common bile duct, right renal pelvis, etc. Except for penetrating gastrointestinal tract or forming hepatic-bronchial fistula, the prognosis is mostly bad.

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