BACKGROUND: Infection is a well-established precipitant of hyperglycemic crisis in patients with diabetes. The concurrent presentation of acute appendicitis and diabetic ketosis (DK) poses a diagnostic challenge because of overlapping abdominal symptoms.

CASE REPORT: A 47-year-old man was diagnosed with acute appendicitis based on characteristic symptoms and positive findings on ultrasound and computed tomography (CT). Laboratory test results revealed elevated serum glucose at 24.46 mmol/L, serum total CO₂ at 21.6 mmol/L, and an elevated serum beta-hydroxybutyrate level of 3178 µmol/L. The patient was diagnosed with new-onset type 2 diabetes mellitus (T2DM), presenting with DK triggered by acute appendicitis. Following the patient’s refusal to undergo surgery, a conservative regimen consisting of intravenous antibiotics, fluid resuscitation, and intensive insulin therapy was successfully administered.

CONCLUSIONS: This case demonstrates that acute appendicitis, although an uncommon trigger, can serve as a critical precipitating factor for severe DK in adults with newly diagnosed T2DM. It highlights the underlying pathophysiological interplay between intra-abdominal infection, systemic inflammatory response, and acute metabolic decompensation. The case emphasizes the importance of maintaining a high index of suspicion for occult infections in patients presenting with DK, particularly when abdominal symptoms are prominent or atypical. Early imaging evaluation and comprehensive laboratory assessment are essential for accurate diagnosis. Moreover, this report illustrates that timely initiation of intensive insulin therapy, appropriate antimicrobial treatment, and supportive care can lead to favorable clinical outcomes. In selected patients who decline surgery, carefully monitored conservative management may represent a viable alternative.

Keywords: appendicitis, Diabetes Mellitus, Type 2, ketosis