Klebsiella Pyogenic Liver Abscess as the Initial Presentation of Undiagnosed Type 2 Diabetes Mellitus: A Case Report and Review

Type 2 diabetes mellitus is associated with impaired innate immunity and increased susceptibility to invasive infections, which may occasionally represent the first clinical manifestation of underlying metabolic disease. Pyogenic liver abscess (PLA), particularly due to Klebsiella pneumoniae, has a well-established association with diabetes and may unmask previously undiagnosed hyperglycemia. We report the case of a 40-year-old male patient with no known past medical history who presented with four days of fever, lethargy, and vomiting. On admission, he was febrile to 39.4°C and tachycardic, with laboratory evidence of leukocytosis. Initial evaluation revealed marked hyperglycemia with glucose levels in the 400s and an HbA1c of 13.1%, consistent with previously undiagnosed type 2 diabetes mellitus. Computed tomography (CT) of the abdomen and pelvis demonstrated a necrotic mass in the right hepatic lobe, along with a smaller adjacent lesion, concerning a PLA. Blood cultures grew Klebsiella pneumoniae in multiple sets, confirming bacteremia. The patient underwent CT-guided aspiration and drainage of the hepatic abscess with placement of a pigtail catheter, yielding purulent material that also grew Klebsiella pneumoniae. His hospital course was complicated by sepsis and acute hypoxic respiratory failure requiring intensive care unit admission. He was treated with intravenous ceftriaxone and metronidazole, resulting in gradual clinical improvement and clearance of bacteremia. Concurrently, insulin therapy was initiated, and the patient received diabetes education for the management of newly diagnosed diabetes. This case highlights invasive infection as a potential initial presentation of undiagnosed diabetes mellitus. Hyperglycemia impairs neutrophil function and host defense, predisposing patients to severe infections such as Klebsiella liver abscesses. Recognition of this relationship is essential, as identification and management of underlying diabetes are critical to optimizing outcomes and preventing recurrence. This case underscores the importance of screening for diabetes in patients presenting with severe or atypical infections and illustrates how metabolic disease may first manifest through life-threatening infectious complications.