Amebic liver abscess: a therapeutic approach.

The clinical presentation of 48 patients with amebic liver abscess was no different than that reported in earlier studies. However, most patients were from countries endemic for parasitic disease. Failure to consider this diagnosis resulted in potentially avoidable surgery for six patients. Although metronidazole was successful primary therapy in 85% of 41 patients so treated, four of seven ruptured abscesses occurred in cases where metronidazole treatment failed. For assessment of factors that might predict metronidazole treatment failures, multiple parameters were analyzed. Of the factors evaluated, only timing of clinical response correlated with successful therapy. Ninety-four percent of metronidazole responders showed dramatic clinical improvement within 72 hours of initiation of therapy, whereas only 33% nonresponders had improved modestly during this time (P = .0014). Therefore, early diagnosis of amebic liver abscess in patients from endemic areas and treatment with metronidazole will result in successful therapy in 85% of cases. Surgical intervention or alternative medical therapy is indicated for those patients who do not respond after 72 hours of metronidazole therapy.