全世界體重過重或肥胖的兒童與青少年之比例逐年上升，罹患第2 型糖尿病的人也持續增加中。不過由於疾病初期可能沒有症狀、症狀不明顯、本身對於疾病的認知缺乏，加上無良好生活作息及沒有規則門診追蹤，容易導致血糖控制差而增加糖尿病相關的併發症和感染的可能性。當糖尿病的病患有腹部疼痛的症狀時，應將糖尿病酮酸中毒列入鑑別診斷之一，而這些人有不明原因持續性的發燒或下背疼痛，尤其是罹患糖尿病多年及血糖控制不佳的人，要警覺是否有腎膿瘍的可能性，才能及早給與正確的診斷與治療。本篇報告一位過去病史有第2 型糖尿病的15 歲女生，近兩個月因放暑假的關係導致服藥順從性不佳，三天前曾高燒至39.4℃，經服用診所醫師所開立的藥後退燒。此次因腹痛到急診，一開始臨床診斷為糖尿病酮酸中毒，後來檢查後發現右側腎盂腎炎及包膜下腎膿瘍，經抗生素治療及經皮引流後症狀漸有改善遂安排出院。

The prevalence of type 2 diabetes is significantly increased in children and adolescents, which is affected by obesity worldwide. However, no or only few symptoms were found at the beginning of the disease.These patients may also lack of knowledge about the disease, have poor drug adherence and loss of follow up.Poor glycemic control may lead to infection and related complications. Diabetic ketoacidosis should be included in the differential diagnosis in young diabetic patients with abdominal pain. When patients who have unexplained persistent fever or low back pain, especially for those having diabetes for a long time or having poor glycemic control, we should be aware of the possibility of renal abscess in order to diagnose and treat early. This case report presents a 15-year-old girl with type 2 diabetes who was brought to the emergency department for an evaluation of abdominal pain. Two months earlier, poor adherence of oral anti-diabetic drugs was noted due to summer vacation. Three days ago fever up to 39.4℃ attacked and the symptom subsided after medications prescribed by a primary physician. This time she was admitted with the impression of diabetic ketoacidosis initially. Repeated physical examination revealed right flank pain and abdominal CT confirmed right pyelonephritis and subcapsular renal abscess. Her condition improved after antibiotics and transcutaneous drainage.