Amebic liver abscess is a complication of amebiasis, which is transmitted via the feco-oral route through infected humans [1]. The incubation period of amebiasis spans from 1 to 4 weeks [2] although it can take days to years [3]. Risk factors for amebic liver abscess include oral-anal intercourse in homosexual men [4], poor hygiene, overcrowding, immigration from endemic regions, and immunosuppression.

The clinical picture is variable, which makes the diagnosis challenging [5]. Amebic liver abscess in endemic regions is associated with an acute illness consisting of fever, weight loss, and abdominal pain [5]. The latter is characterized as a dull, achy, and unremitting pain in the right upper quadrant (RUQ) that radiates to right shoulder or scapula. Pain exacerbation occurs with deep inspiration and coughing. Other manifestations include rigors, nausea, emesis, and diarrhea. Patients may also report a history of dysentery [1]. A minority of patients will exhibit pulmonary symptoms such as coughing and chest pain. When a bronchopleural fistula forms, the productive cough yields brown paste-like substance [6].

Complications

Although uncommon, complications include peritoneal rupture and/or involvement of organs such as the heart and lungs.

Physical exam

Fever is noted in nearly all patients. Remarkable signs on the physical exam include hepatomegaly and tenderness in the RUQ and possibly epigastric region. Also, patients with pulmonary involvement will exhibit rales and diminished breath sounds at the right lung base upon auscultation. If present, peritoneal signs include rebound tenderness, guarding, as well as the absence of bowel sounds. Finally, pleural rub and/or pericardial rub are heard in those with complications.

• Generalized Lymphadenopathy

  In the presence of fever, generalized lymphadenopathy, and elevated serum aminotransferase levels, HIV infection was suspected and then confirmed by a de novo seroconversion of HIV antibody. [ncbi.nlm.nih.gov]

• Fever

  Common clinical symptoms were fever (93%) and abdominal pain (93%). Common signs were right upper quadrant tenderness (60%), hepatomegaly (67%). [ncbi.nlm.nih.gov]

• Weight Loss

  Amebic liver abscess in endemic regions is associated with an acute illness consisting of fever, weight loss, and abdominal pain. [symptoma.com]

  However, it can invade your colon wall, causing symptoms of: fever colitis fatigue nausea diarrhea tenesmus bloody stools intestinal gas loss of appetite severe dehydration stomach pain, cramping unintentional weight loss These symptoms typically last [healthblurbs.com]

  A 53-year-old man was admitted because of high fever, epigastralgia, back pain, and body weight loss. Abdominal CT scan revealed liver abscess. Abscess fluid by ultrasound-guided transhepatic drainage showed negative for bacterial culture. [ci.nii.ac.jp]

  loss Antibiotics such as metronidazole (Flagyl) or tinidazole (Tindamax) are the usual treatment for liver abscess. [medlineplus.gov]

  loss Exams and Tests The health care provider will perform a physical examination. [ufhealth.org]

• Chills

  RESULTS: According to our study, the common clinical symptoms and signs are abdominal pain (85.5 %), fever and chills (74.2 %), and abdominal tenderness (69.4 %). [ncbi.nlm.nih.gov]

  Most of the patients were suffering from abdominal pain (85.5 %), fever and chills (74.2 %), and abdominal tenderness (69.4 %; Table 2 ). [bmcfampract.biomedcentral.com]

  Additional symptoms caused by amebic liver abscess include: chills edema ascites jaundice sweating joint pain Without treatment, amebic liver abscess may rupture and spread into your abdominal cavity, lungs or lung lining, sac around heart and brain. [healthblurbs.com]

  But people with amebic liver abscess do have symptoms, including: Abdominal pain, more so in the right, upper part of the abdomen; pain is intense, continuous or stabbing Cough Fever and chills Diarrhea (in only one-third of patients) General discomfort [medlineplus.gov]

• Malaise

  […] abscess do have symptoms, including: Abdominal pain, more so in the right, upper part of the abdomen; pain is intense, continuous or stabbing Cough Fever and chills Diarrhea (in only one-third of patients) General discomfort, uneasiness, or ill feeling ( malaise [medlineplus.gov]

  28 (45.2 %) Abdominal tenderness 43 (69.4 %) 14 (22.6 %) 29 (46.8 %) Anorexia 39 (62.9 %) 14 (22.6 %) 25 (40.3 %) Hepatomegaly 37 (59.7 %) 14 (22.6 %) 23 (37.1 %) Jaundice 25 (40.3 %) 9 (14.5 %) 16 (25.8 %) Nausea 23 (37.1 %) 8 (12.9 %) 15 (24.2 %) Malaise [bmcfampract.biomedcentral.com]

  Patients may experience general malaise or present with frank sepsis and right upper quadrant pain. [radiopaedia.org]

• Fatigue

  However, it can invade your colon wall, causing symptoms of: fever colitis fatigue nausea diarrhea tenesmus bloody stools intestinal gas loss of appetite severe dehydration stomach pain, cramping unintentional weight loss These symptoms typically last [healthblurbs.com]

  The diagnosis was based on: 1) clinical findings (right upper quadrant pain, fever, malaise or fatigue, vomiting, weight loss, hepatomegaly, and/or dehydration signs) 2) sonographic evidence of an abscess (hypoechogenic or anechoic lesion with central [omicsonline.org]

  fatigue) High risk of recurrence, e.g., through self-inoculation (hand to mouth) A chronic form is also possible, which is clinically similar to inflammatory bowel disease. [amboss.com]

  These include fever, abdominal pain, fatigue, and nausea with fever being the most common symptom present in up to 90% of cases of pyogenic abscesses. [clinicaladvisor.com]

• Cough

  A minority of patients will exhibit pulmonary symptoms such as coughing and chest pain. When a bronchopleural fistula forms, the productive cough yields brown paste-like substance. [symptoma.com]

  Each child presented with a history of fever and gastrointestinal symptoms, and two-thirds presented with cough or difficulty breathing. Most (81%) patients had hepatomegaly on physical examination and some had a well-defined mass. [ncbi.nlm.nih.gov]

  But people with amebic liver abscess do have symptoms, including: Abdominal pain, more so in the right, upper part of the abdomen; pain is intense, continuous or stabbing Cough Fever and chills Diarrhea (in only one-third of patients) General discomfort [medlineplus.gov]

• Pleural Effusion

  Gross fluid derangements including pleural effusion, edema and ascities were observed in 39% cases and 6% had rupture of abscess. All patients were treated with standard antimicrobial regimen and discharged with initial recovery. [ncbi.nlm.nih.gov]

  In 5 patients, pleural effusion was observed in chest radiographs. IHA titer was 128 in 10 patients and 512 in 8 patients. Median days to defervescence was 2 (range 1–5 days). [wwwnc.cdc.gov]

  Pleural Effusion secondary to amoebic liver abscess 14. An amoebic liver abscess causing a bulge in the dome of the diaphragm 15. Amoebic liver abscess burst into the right pleural cavity 16. 17. 18. I. [slideshare.net]

  effusion perihepatic fluid collection gastric or colonic involvement retroperitoneal extension Ultrasound May appear as a hypoechoic lesion with low-level internal echoes and absence of significant wall echoes. [radiopaedia.org]

• Dry Cough

  It was followed by dry cough and occasional chest pain which was pleuritic in nature. He had consulted a local physician and taken empirical antibiotics and antipyretics for the same. [jdeonline.in]

• Abdominal Pain

  We present a case of a previously healthy 43-year-old Canadian man presenting with constitutional symptoms and right upper quadrant abdominal pain. [ncbi.nlm.nih.gov]

• Diarrhea

  They are more likely to be present if the patient has diarrhea as a presenting symptom or has had diarrhea in the recent past. [ncbi.nlm.nih.gov]

  Abdominal cramps, vomiting, diarrhea, and dizziness also may occur. Dark urine may occur from a metabolite of the drug. [emedicine.medscape.com]

• Nausea

  Other manifestations include rigors, nausea, emesis, and diarrhea. Patients may also report a history of dysentery. A minority of patients will exhibit pulmonary symptoms such as coughing and chest pain. [symptoma.com]

  Although paromomycin may occasionally cause nausea, abdominal cramps, or diarrhea, it is the preferred luminal amebicidal. The details on the luminal amebicides are discussed in Medication. [emedicine.medscape.com]

  However, it can invade your colon wall, causing symptoms of: fever colitis fatigue nausea diarrhea tenesmus bloody stools intestinal gas loss of appetite severe dehydration stomach pain, cramping unintentional weight loss These symptoms typically last [healthblurbs.com]

  The incidence of nausea and metallic taste was significantly lower in the patients given satranidazole (P .005). [ncbi.nlm.nih.gov]

  Fever and chills 46 (74.2 %) 18 (29.0 %) 28 (45.2 %) Abdominal tenderness 43 (69.4 %) 14 (22.6 %) 29 (46.8 %) Anorexia 39 (62.9 %) 14 (22.6 %) 25 (40.3 %) Hepatomegaly 37 (59.7 %) 14 (22.6 %) 23 (37.1 %) Jaundice 25 (40.3 %) 9 (14.5 %) 16 (25.8 %) Nausea [bmcfampract.biomedcentral.com]

• Loss of Appetite

  However, it can invade your colon wall, causing symptoms of: fever colitis fatigue nausea diarrhea tenesmus bloody stools intestinal gas loss of appetite severe dehydration stomach pain, cramping unintentional weight loss These symptoms typically last [healthblurbs.com]

  […] of appetite Sweating Weight loss Antibiotics such as metronidazole (Flagyl) or tinidazole (Tindamax) are the usual treatment for liver abscess. [medlineplus.gov]

  […] of appetite Sweating Weight loss Exams and Tests The health care provider will perform a physical examination. [ufhealth.org]

• Epigastric Mass

  A 43-year-old Filipino male was admitted to a Manila hospital with a 1 month history of epigastric pain and fever, and was found to have a palpable epigastric mass. [ncbi.nlm.nih.gov]

• Hepatomegaly

  Most (81%) patients had hepatomegaly on physical examination and some had a well-defined mass. [ncbi.nlm.nih.gov]

• Liver Tenderness

  RESULTS: (i) Mean body temperature, liver tenderness, total leukocyte count (TLC), serum alanine aminotransferase (ALT) and liver span were significantly decreased in the aspiration group on days 8 and 15 as compared to non-aspiration group especially [ncbi.nlm.nih.gov]

  The end-points were subsidence of fever and liver tenderness, normalization of total leukocyte count (TLC), alanine aminotransferase (ALT) and liver span. [tropicalgastro.com]

  Physical examination: Fever (low-grade or high spiking) Hepatomegaly and liver tenderness, which is accentuated by movement or percussion. Splenomegaly is unusual, except with a chronic abscess. [enotes.tripod.com]

• Night Sweats

  Night sweats. Nausea and vomiting. Anorexia and weight loss. Cough and dyspnoea due to diaphragmatic irritation. Referred pain to the right shoulder. [patient.info]

Patients suspected to have an amebic hepatic abscess are assessed with a review of their personal history and risk factors, physical exam findings, and the appropriate studies.

Laboratory tests

The workup should include a complete blood count (CBC), which will likely reveal leukocytosis and possibly anemia. Furthermore, analysis of liver function tests (LFTs) in acute illness will reflect elevated aspartate aminotransferase (AST) levels while cases of chronic liver abscess are associated with normal AST levels and increased alkaline phosphatase. The latter is typically high in most cases.

Diagnostic tests

Since most individuals with amebic liver abscess do not have coexistent intestinal amebiasis, only a small percentage will have detectable cysts in stool [5] [7]. Hence, stool analysis is not typically useful. Among the various stool studies, antigen or DNA detection of E. histolytica is the preferred diagnostic technique [5].

Serologic studies, which are commonly used to diagnose an amebic liver abscess, yield positive results despite a discrepancy with negative stool tests [8]. The enzyme immunoassay (EIA) test is sensitive, rapid and inexpensive [9]. Also, an amebic liver abscess can be diagnosed through the detection of the E. histolytica galactose lectin antigen using enzyme-linked immunosorbent assay (ELISA). This method is sensitive and rapid [1]. Additionally, there are antibody and antigen point-of-care tests currently under investigation [10].

Imaging

A liver abscess can be detected by various imaging modalities although they do not identify the etiology (amebic versus pyogenic ) [5]. Abdominal ultrasonography, the recommended initial study, demonstrates a sensitivity of 75% to 90% and differentiates an abscess from solid lesions such as tumors. Computed tomography (CT) scan is associated with an up to 95% sensitivity and contrast-enhancement helps distinguish an abscess from a tumor. Magnetic resonance imaging (MRI), like CT, is sensitive but not specific for the diagnosis of an abscess.

Other

Percutaneous needle aspiration of the hepatic abscess can be performed if needed [11].

• Atelectasis

  When an abscess is situated near the dome of the liver, the patient may experience pain in the right shoulder or a cough as a result of diaphragmatic irritation or atelectasis. [enotes.tripod.com]

  May be atelectasis or pleural effusion. Ultrasonography can show abscess and also allow guided percutaneous aspiration and drainage. Aspirated fluid should be sent for culture and sensitivity. It also allows biliary tree examination. [patient.info]

• Multiple Liver Cysts

  Ultrasound, MRI and CT scanning will show multiple liver cysts. Treatment : this is only needed if symptoms occur. As with simple cysts, options include aspiration-sclerotherapy and deroofing. Liver transplantation is occasionally employed. [patient.info]

• Pleural Effusion

  Gross fluid derangements including pleural effusion, edema and ascities were observed in 39% cases and 6% had rupture of abscess. All patients were treated with standard antimicrobial regimen and discharged with initial recovery. [ncbi.nlm.nih.gov]

  In 5 patients, pleural effusion was observed in chest radiographs. IHA titer was 128 in 10 patients and 512 in 8 patients. Median days to defervescence was 2 (range 1–5 days). [wwwnc.cdc.gov]

  Pleural Effusion secondary to amoebic liver abscess 14. An amoebic liver abscess causing a bulge in the dome of the diaphragm 15. Amoebic liver abscess burst into the right pleural cavity 16. 17. 18. I. [slideshare.net]

  effusion perihepatic fluid collection gastric or colonic involvement retroperitoneal extension Ultrasound May appear as a hypoechoic lesion with low-level internal echoes and absence of significant wall echoes. [radiopaedia.org]

• Pleural Rub

  Finally, pleural rub and/or pericardial rub are heard in those with complications. [symptoma.com]

  Diaphragmatic irritation from abscess might refer pain to the right shoulder or result in cough or pleural rub. Classified by presumed origin: Bacterial: Up to 50% develop from biliary tract ( cholangitis ). [hopkinsguides.com]

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3. Garcia L, Bruckner DS. Diagnostic medical parasitology. 3rd ed. Washington, D.C.: AMA Press; 1997.
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9. Restrepo MI, Restrepo Z, Elsa Villareal CL, Aguirre A, Restrepo M. Diagnostic tests for amoebic liver abscess: comparison of enzyme-linked immunosorbent assay (ELISA) and counterimmunoelectrophoresis (CIE). Rev Soc Bras Med Trop. 1996;29(1):27-32.
10. Leo M, Haque R, Kabir M, et al. Evaluation of Entamoeba histolytica antigen and antibody point-of-care tests for the rapid diagnosis of amebiasis. J Clin Microbiol. 2006;44(12):4569-71.
11. Bammigatti C, Ramasubramanian NS, Kadhiravan T, Das AK. Percutaneous needle aspiration in uncomplicated amebic liver abscess: a randomized trial. Trop Doct. 2013;43(1):19-22.