What is the initial evaluation for a girl presenting with enuresis, polydipsia, polyuria, and weight loss?

Initial Evaluation: Random Blood Glucose

In a child presenting with enuresis, polydipsia, polyuria, and weight loss, perform a random blood glucose immediately to rule out type 1 diabetes mellitus, which is a medical emergency that can rapidly deteriorate into diabetic ketoacidosis. 1

Why Random Blood Glucose Takes Priority

The constellation of symptoms—polydipsia, polyuria, weight loss, and new-onset enuresis—represents the classic triad of type 1 diabetes mellitus presentation in children. 1, 2, 3

• Type 1 diabetes is diagnosed immediately when classic symptoms are present with a random plasma glucose ≥200 mg/dL (11.1 mmol/L), and delays in diagnosis must be avoided as the metabolic state can deteriorate rapidly. 1

• Polyuria and polydipsia occur in 96% of children presenting with new-onset type 1 diabetes, and weight loss is present in 76.6% of cases. 2

• Nocturnal enuresis is reported in 19-31% of children under 10 years presenting with type 1 diabetes, making it an important presenting symptom that should raise immediate suspicion for diabetes. 3

• Approximately 25-55% of children with new-onset type 1 diabetes present in diabetic ketoacidosis, which requires immediate recognition and treatment. 2, 3

When to Perform Urine Analysis

Urine analysis and culture should be performed after diabetes has been ruled out or as part of the comprehensive evaluation, but they are not the priority in this clinical scenario. 1, 4

• While every enuretic child should have screening urinalysis to rule out urinary tract infection, this recommendation applies to isolated enuresis without systemic symptoms. 1, 4

• The presence of polydipsia, polyuria, and weight loss transforms this from simple enuresis into a presentation highly suspicious for diabetes mellitus or other metabolic disorders. 1, 3

• Urine dipstick testing for glycosuria would support the diagnosis of diabetes mellitus, but glycosuria means diabetes must be immediately excluded with blood glucose measurement. 1

Clinical Algorithm

1. Measure random blood glucose immediately in any child with enuresis plus polydipsia, polyuria, and/or weight loss. 1

2. If random glucose ≥200 mg/dL with classic symptoms, diagnose diabetes and initiate treatment immediately without waiting for confirmatory tests. 1

3. If glucose is normal, then proceed with urinalysis and urine culture to evaluate for urinary tract infection or other causes of enuresis. 1, 4

4. Consider first-morning urine specific gravity (<1.015 suggests diabetes insipidus or other concentrating defects) if diabetes is excluded. 1, 5

Critical Pitfalls to Avoid

• Never delay blood glucose testing to perform urinalysis first when systemic symptoms (polydipsia, polyuria, weight loss) are present alongside enuresis. 1

• Do not assume enuresis with polyuria/polydipsia is simply a primary enuresis case requiring only urinalysis—this combination demands immediate metabolic evaluation. 3, 5

• Recognize that children under 2 years are more difficult to diagnose and more likely to present in severe diabetic ketoacidosis, requiring heightened vigilance. 3

• The average duration of symptoms before diagnosis is 17 days, indicating that many cases are missed initially—maintain high clinical suspicion. 2