Common presentations of amebic liver abscess

Study objective: The most common extraintestinal manifestation of Entamoeba histolytica, the agent of amebiasis, is a hepatic abscess. This infection is common throughout the world and can be associated with life-threatening consequences. Given the often nonspecific nature of the complaints related to an amebic abscess, a retrospective review of patients with confirmed dis ease was done to recognize the most common patterns of presentation. Methods: A retrospective case series was conducted of all patients with con firmed amebic liver abscess over a 5-year period. All available emergency d epartment and inpatient records were reviewed. Age, sex, country of origin, chief complaint (including duration), vital signs, and physical and labora tory findings were recorded. The use of ultrasonography, computed tomograph y scan, chest radiograph, and serum antibodies was noted, as well as the fi nal ED diagnosis. Results: Seventy-five patients were reviewed; mean patient age was 35.5 yea rs, 80% were male, and Mexico was the country of origin for 64%. The most c ommon complaint was fever (77%), followed by abdominal pain (72%), which wa s most often located in the right upper quadrant. Cough (16%), chest pain ( 19%), and chest radiographic abnormalities (57%) were also common. The majo rity of patients (69%) had symptoms for less than 13 days. The WBC count wa s the most consistent laboratory abnormality (83%),whereas the liver aminot ransferase, alkaline phosphatase, and bilirubin levels were often normal. M ost patients received their diagnoses on the basis of ultrasonography (85%) , followed by a confirmatory serum antibody titer (88%). The diagnosis of a mebic liver abscess was correctly made in the ED in 31.5% of the patients, with the most common misdiagnoses being cholecystitis (16.4%), hepatitis (1 2.3%), and pneumonia (9.6%), Conclusion: Patients with amebic liver abscess do present to EDs in the sou thwestern United States, especially in areas with a high immigrant populati on from endemic areas. Patients with complaints of fever and right upper qu adrant abdominal pain, especially men of Hispanic origin, warrant a high de gree of vigilance. Whereas most laboratory studies are unhelpful, the diagn osis can often be made in the ED by means of a bedside ultrasonographic tes t. Treatment should be initiated with metronidazole with disposition to an inpatient medical service.