Liver abscess due to Klebsiella pneumoniae in a healthy 12-year-old boy
A 12-year-old boy was admitted to Seoul St. Mary's Hospital after 5 days of fever. He had right upper quadrant (RUQ) abdominal pain when breathing for one day, but showed no other gastrointestinal symptoms such as vomiting or diarrhea. He was visiting Seoul as a tourist from Los Angeles, CA, USA. He had been healthy and had no history of any other disease; however, his grandfather had died of liver cancer related to hepatitis C. The patient had a travel history to lake about 2 weeks ago and appeared to have drunk contaminated water during swimming.\nBased on physical examination, he appeared healthy. His body temperature was 39.6℃ and he had RUQ tenderness. A complete blood count showed hemoglobin, 11.7 g/dL; white blood cells, 16,810/mm3 with segmented neutrophils of 78.2%; and platelets, 270,000/mm3. The erythrocyte sedimentation rate was 120 mm/hr and his C-reactive protein was more than 34.1 mg/dL. Blood chemistry including liver function tests were normal. Abdomen and pelvis CT scans revealed a large (6.9 cm×7.1 cm×7.3 cm), lobular, low-density abscess in liver segments 7 and 8 with periportal edema and a small amount of ascites (). The results of the tests for hepatitis viral markers, alpha fetoprotein, immunoglobulins, complements, and amoeba antibodies for the purpose of differential diagnosis were all normal. He was started on intravenous meropenem and metronidazole.\nOn hospital day 4, ultrasound-guided drainage was performed by pig-tail catheter, and 40 mL of pus was drained. After drainage, the patient's fever began to subside and he began to feel more comfortable. On hospital day 9, K. pneumoniae was proven by bacterial culture. The isolate was extended-spectrum beta-lactamase-negative and was sensitive to meropenem and gentamicin. We added gentamicin to initiate triple-antibiotic therapy. We removed the pig-tail catheter on hospital day 14 because the drainage had ceased. At follow-up, a repeated complete blood count showed white blood cells, 8,500/mm3 with segmented neutrophils of 58.1%; erythrocyte sedimentation rate, 113 mm/hr; and C-reactive protein, 1.71 mg/dL. On hospital day 21, abdominal and pelvic CT scans showed that the liver abscess was greatly diminished, but also showed a large amount of right pleural effusion with passive collapse of the right lower lung (). Chest posterior-anterior (PA) also showed a large amount of right pleural effusion (). No respiratory symptoms such as dyspnea were present. We inserted a pig-tail catheter for pleural effusion and drained 100 mL of fluid, which was shown to be transudate. The next day, as the drainage of pleural effusion ceased and chest PA showed no remaining fluid (), we removed the pig-tail catheter. After treatment with intravenous antibiotics for 3 weeks (hospital day 22), we discharged the patient with oral administration of cefixime. The pleural effusion showed no evidence of bacteria in culture.