Pediatric Endocrinology
Domain focus
Pediatric endocrinology tests growth, puberty, thyroid disease, adrenal disorders, and diabetic ketoacidosis.
Core rules
- Short stature: plot height, calculate mid-parental height, and assess growth velocity. Bone age helps distinguish constitutional delay from pathology.
- Congenital hypothyroidism is detected by newborn screening; early levothyroxine prevents intellectual disability.
- Type 1 diabetes: polyuria, polydipsia, weight loss, hyperglycemia; check venous pH, bicarbonate, and ketones.
- DKA: dehydration, Kussmaul breathing, acidosis. Give isotonic fluid for shock, then rehydrate slowly; start insulin after fluids; monitor potassium and treat cerebral edema urgently.
- Precocious puberty: breast development before 8 years in girls or testicular enlargement before 9 years in boys warrants evaluation.
Worked example
A 10-year-old presents with vomiting, abdominal pain, polyuria, glucose 450 mg/dL, pH 7.15, bicarbonate 10 mmol/L, and large ketones. Reasoning: this is DKA. Give a 10 mL/kg isotonic bolus only if shock is present, then begin rehydration over 24–48 hours. Start insulin infusion after initial fluids, add potassium when appropriate, and monitor neurologic status for cerebral edema. Rapid fluid or insulin correction increases cerebral edema risk.
Traps
- Giving bicarbonate routinely in DKA.
- Starting insulin before fluid resuscitation.
- Missing adrenal crisis in a child with hypotension, hyponatremia, and hyperkalemia.