Diabetic ketoacidosis (DKA) is a critical complication of diabetes, primarily associated with type 1 diabetes mellitus. It is often precipitated by infections, which can complicate the clinical picture. Procalcitonin (PCT) is a biomarker traditionally used to identify bacterial infections; however, its elevation can occur in the absence of infection, particularly in metabolic crises like DKA. This case report aims to investigate the dynamics of PCT levels in a patient with DKA without any infectious etiology, highlighting the importance of clinical context in interpreting PCT results.

We present a case of a 30-year-old female with a history of type 1 diabetes who was admitted to the ICU with DKA. Upon admission, she exhibited symptoms including confusion, abdominal pain, and vomiting. Initial laboratory tests revealed severe metabolic acidosis and a blood glucose level of 687 mg/dL. PCT levels were measured, starting at 0.96 ng/mL and escalating to 13.97 ng/mL on the second day of admission. Despite extensive investigations, including blood cultures and imaging, no infections were detected. The patient was treated with fluid resuscitation and insulin without the use of antibiotics.

Over the course of her hospitalization, the patient’s PCT levels were monitored, showing a peak at 13.97 ng/mL on day two, followed by a decrease to 4.5 ng/mL by day three. Clinical signs of infection were absent throughout her stay, and all cultures returned negative. The patient's metabolic parameters improved with standard DKA management, leading to her discharge on day three with stabilized blood glucose levels and a modified insulin regimen.

This case illustrates that markedly elevated PCT levels can occur in DKA without any evidence of infection. The elevation may be attributed to non-infectious inflammatory responses associated with metabolic stress. Clinicians should interpret PCT levels in the context of the overall clinical picture, as reliance on PCT alone could lead to unnecessary antibiotic therapy. This case emphasizes the need for a systematic approach to DKA management, ensuring that potential inflammatory markers are evaluated cautiously to avoid misdiagnosis and inappropriate treatment. Further research is warranted to explore the mechanisms behind PCT elevation in non-infectious conditions such as DKA.