Navigating a Delicate Balance: Antibiotic Allergy in the Setting of Renal Infection and Diabetic Ketoacidosis

Acute pyelonephritis is a bacterial infection of the renal parenchyma that requires prompt recognition and antibiotic therapy to prevent complications such as sepsis and chronic renal inflammation. We present a case of a 26-year-old woman with poorly controlled type 1 diabetes mellitus and a documented beta-lactam allergy who presented with atypical symptoms, including flank pain without urinary complaints. Laboratory evaluation demonstrated leukocytosis with a negative urinalysis. CT of the abdomen revealed left lobar nephronia with early contralateral involvement of the right kidney. Given her allergy history, she was treated with levofloxacin. During her hospital stay, she developed nausea, vomiting, and metabolic abnormalities consistent with euglycemic diabetic ketoacidosis (eDKA), necessitating intensive care management with dextrose-containing fluids, insulin, and electrolyte correction. The patient improved with appropriate medical management and was discharged in stable condition. This report underscores the importance of individualized antibiotic selection in patients with documented drug allergies, the role of imaging in atypical clinical presentations, and the need for sustained observation for metabolic complications like eDKA in patients with poorly controlled diabetes mellitus and infection.