Diabetic Ketoacidosis and Other Differential Diagnoses in Type 1 Diabetes

Life-Threatening Differentials

The American Diabetes Association recommends that diabetic ketoacidosis (DKA) be ruled out immediately in any type 1 diabetic patient presenting with vomiting, as it is a life-threatening emergency that commonly presents with vomiting in adolescents with type 1 diabetes 1, 2
DKA is the primary concern in any type 1 diabetic patient presenting with vomiting, as approximately one-third of children with type 1 diabetes present with DKA, and it develops over hours to days 3
Classic presentation of DKA includes polyuria, polydipsia, weight loss, dehydration, nausea, vomiting, abdominal pain, and Kussmaul respirations 1
Vomiting accompanied by hyperglycemia and ketosis indicates DKA until proven otherwise 4, 2
The American Diabetes Association notes that hyperosmolar hyperglycemic state (HHS) is less common in type 1 diabetes but can occur, especially in mixed presentations, and develops over days to a week with more severe dehydration and altered mental status 1

Hypoglycemia can cause nausea and vomiting, especially if severe or with rapid glucose fluctuations, and is defined as a capillary blood glucose of less than 60 mg/dL 5, 4
Severe hyperglycemia alone can directly cause nausea and vomiting even without ketoacidosis, and marked hyperglycemia substantially slows gastric emptying, exacerbating nausea 5, 6

Diabetic gastroparesis affects 30-50% of patients with longstanding diabetes, though less common in adolescents, and presents with nausea, vomiting, early satiety, and postprandial fullness 5
Acute gastroenteritis can precipitate DKA due to stress of illness and dehydration, and distinguish by presence of diarrhea, fever, and absence of severe hyperglycemia/ketosis 4, 2

Infections are a common precipitating factor for DKA, and upper respiratory infections can trigger counter-regulatory hormone release, increasing insulin resistance and precipitating DKA 5
Any infection increases insulin requirements and can lead to vomiting through direct illness effects 4, 2

SGLT2 inhibitor-associated euglycemic DKA is less common in type 1 diabetes but increasingly prescribed off-label, and presents with DKA symptoms but with near-normal or only mildly elevated glucose 6
Insulin omission or inadequate dosing is the main cause of DKA in established type 1 diabetes patients, and inquiring about insulin adherence, missed doses, or pump malfunction is crucial 1

Eating disorders are a risk factor for recurrent DKA through intentional insulin omission, and are more common in adolescent females with type 1 diabetes 1
The American College of Obstetricians and Gynecologists recommends considering pregnancy in female adolescents of childbearing age, as pregnancy increases DKA risk and alters insulin requirements 1

Immediate bedside testing should include capillary blood glucose, blood or urine ketones, and vital signs including mental status assessment 4, 2, 6
Laboratory evaluation should include complete metabolic panel, serum ketones, and anion gap calculation 6, 1