Hyperglycemic Hyperosmolar State As the Initial Presentation of Type 1 Diabetes Mellitus in an Adolescent: A Case Report.

Hyperglycemic hyperosmolar state (HHS) is a rare but life-threatening hyperglycemic emergency in children and adolescents. It is characterized by severe hyperglycemia, hyperosmolality, and dehydration, with absent or limited ketoacidosis. Although more commonly associated with type 2 diabetes mellitus, HHS may also occur as the initial presentation of type 1 diabetes mellitus in pediatric patients. We report the case of a previously healthy 13-year-old boy presenting with a three-week history of polydipsia and nocturnal polyuria. Initial evaluation revealed profound hyperglycemia (>1,000 mg/dL), hyperosmolality, clinical dehydration, and only mild acidosis. During treatment, the patient experienced marked fluctuations in blood glucose, requiring repeated adjustments of insulin and dextrose infusions, electrolyte replacement, and pediatric intensive care monitoring. This case highlights the diagnostic challenges of pediatric HHS and emphasizes the importance of early recognition, prioritizing fluid resuscitation, cautious insulin administration, and close biochemical monitoring to prevent complications.