Liver abscess is a bacterial hepatic abscess or amebic liver abscess. Patients have fever, nausea/vomiting, and loss of appetite; About 50% of patients have liver signs (tenderness, hepatomegaly, and jaundice).
CASES/YEAR
10,800 (US); 216,000 (Global)
OTHER NAMES
Abscess of liver; Pyogenic hepatic abscess; Amebic liver abscess;
INCUBATION
Estimated: several days to several months;
INITIAL SYMPTOMS
Fever, nausea & vomiting, loss of appetite; About 50% of patients have RUQ signs (tenderness, hepatomegaly, and jaundice); [Harrisons, p. 401]
COMMENTS
Usually arise as local spread from peritoneal infection (biliary tract, pelvic, and other) or hematogenous seeding; Leukocytosis common; 70% have increased serum alkaline phosphatase; Amebic liver abscesses may occur months (usually <5 months) after E. histolytica exposure. [Harrisons, p. 401, 415] One study showed that the chest x-ray was abnormal in 33% of the cases with elevation of the right hemidiaphragm, right basilar infiltrate, atelectasis, or pleural effusion. [Cohen, 3rd Ed, p. 435] Amebic liver abscesses are usually single and in the right lobe. They are more common in men (8:1) and may develop insidiously. [Merck Manual, p. 1645] Blood cultures are positive in about 1/2 of patients with pyogenic abscesses, and about 15% develop septic shock. Aspirate culture is positive in 70-80%. Patients with amebic abscess may have been colonized years before and may have no history of amebic colitis. Jaundice occurs in pyogenic abscesses, but is extremely uncommon in amebic abscesses. [Cecil, p. 977, 980] Stool for O&P: positive in less than 20-40% of patients with amebic liver abscesses. [Wallach, p. 1194] Jaundice is unusual. If present, it is usually caused by extrahepatic biliary disease. [ID, p. 789]
DIAGNOSTIC
Abdominal CT, MRI, & ultrasonography; Gram stain & culture of aspirate; Echinococcal & E.. histolytica serology are useful in nonendemic areas; [ABX Guide] Dx of amebic abscess = lesion + positive serology; Serology highly sens/spec; [Cecil, p. 980]
SIGNS & SYMPTOMS
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>fatigue, weakness
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>fever
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>fever, biphasic or relapsing
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G abdominal pain
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G diarrhea
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G hepatomegaly
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G jaundice
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G liver function test, abnormal
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G nausea, vomiting
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H anemia
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H leukocytosis
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R chest pain
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R cough
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X lung infiltrates
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X pleural effusions
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*pericarditis
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*sepsis
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*weight loss
ENTRY
Ingestion, Swimming, Sexual Contact
SOURCE
Person-to-Person, Human Fecal-Oral, Eating Contaminated Food, Eating Contaminated Produce, Waterborne (Ingesting, Inhaling, or Swimming)
RISK FACTORS
- AIDS patients
- Cancer patients
TREATMENT
Drainage of amebic liver abscesses is rarely needed. [Harrisons, p. 415]
REFERENCES FOR CASES/YEAR
1. (US) US incidence: 3.6/100,000 per year; [Cecil, p. 977] Calculate: 3.6 X 3000 = 10,800;
2. (Global) Global incidence of 1.1-2.3 cases/100,000 per year; [Cecil, p. 977] In Europe, the incidence was recently measured at 18 cases per 100,000 hospital admissions and 2-3 cases per 100,000 population. [Cohen, 3rd Ed, p. 435] Calculate: Use US cases/yr: 10,800 X 20 = 216,000;