Pediatrics · Year 3 · from Pediatrics

Case 2: Congenital Adrenal Hyperplasia - Salt-Wasting Crisis

Patient Demographics

  • Age: 12-day-old male
  • Sex: Male

Chief Complaint

"He won't eat and seems very weak."

History of Present Illness

A 12-day-old male is brought to the emergency department with poor feeding, lethargy, and vomiting for 2 days. He was born at term via uncomplicated vaginal delivery. Birth weight was 3.5 kg. He was breastfeeding well initially but has become increasingly difficult to feed over the past 48 hours, with frequent spitting up. Today, he has been very sleepy and difficult to arouse. His diaper has been dry for 8 hours. Newborn screening results are pending. There is no family history of endocrine disorders, but the parents are first cousins.

Physical Examination

  • General: Lethargic, weak cry, mottled skin, poor responsiveness
  • Vital signs: Temp 36.2°C (low), HR 180 bpm, RR 55/min, BP 55/35 mmHg, Weight 3.1 kg (down from 3.5 kg at birth - 11% weight loss)
  • HEENT: Sunken fontanelle, dry mucous membranes
  • Cardiovascular: Tachycardic, weak pulses, delayed capillary refill (4 seconds)
  • Respiratory: Tachypneic, clear lungs
  • Abdomen: Soft, non-distended
  • Genitourinary: Normal male external genitalia, normal phallus size, bilateral descended testes
  • Skin: Hyperpigmented scrotum and nipples

Workup

  • Point-of-care glucose: 42 mg/dL (low)
  • BMP: Na 118 mEq/L (critically low), K 7.8 mEq/L (critically high), Cl 95 mEq/L, HCO3 14 mEq/L, BUN 35 mg/dL, Cr 0.8 mg/dL, Glucose 38 mg/dL
  • VBG: pH 7.22
  • ECG: Peaked T waves, widened QRS
  • 17-hydroxyprogesterone: 8,500 ng/dL (markedly elevated; normal <100)
  • Cortisol: 2.1 mcg/dL (low for stress)
  • ACTH: 450 pg/mL (markedly elevated)
  • Newborn screen (just resulted): Elevated 17-OHP flagged

Diagnosis

Congenital adrenal hyperplasia (21-hydroxylase deficiency, salt-wasting form) with adrenal crisis

Clinical Reasoning

This male infant presents with classic salt-wasting adrenal crisis from 21-hydroxylase deficiency CAH. The presentation at 10-14 days of life is typical, as it takes time for the salt-wasting to become clinically apparent after the protective effect of maternal hormones wears off. The hyponatremia, hyperkalemia, hypoglycemia, and shock reflect both glucocorticoid and mineralocorticoid deficiency. The hyperpigmentation results from ACTH excess (ACTH shares precursors with melanocyte-stimulating hormone). Males present with crisis because they have normal genitalia at birth (unlike virilized females who are often diagnosed earlier) and may not be diagnosed until critically ill.

Management

  1. Immediate resuscitation: IV/IO access, NS 20 mL/kg bolus; repeat as needed
  2. Treat hyperkalemia: Calcium gluconate 100 mg/kg IV (cardioprotection), insulin/glucose, kayexalate if needed
  3. Treat hypoglycemia: D10W bolus 2 mL/kg, then continuous dextrose infusion
  4. Stress-dose hydrocortisone: 25 mg IV bolus, then 25 mg IV Q6h (50-100 mg/m²/day)
  5. Mineralocorticoid: Fludrocortisone 0.1 mg PO daily once stable and able to take orally
  6. Salt supplementation: NaCl 1-2 g/day in divided doses with feeds
  7. Monitoring: Frequent electrolytes, glucose; cardiac monitoring
  8. Long-term: Maintenance hydrocortisone (10-15 mg/m²/day divided TID), fludrocortisone, NaCl supplements; stress dosing education; genetic counseling for family

Clinical Image

Image Description: Clinical presentation demonstrating the metabolic derangements and clinical findings associated with adrenal insufficiency in pediatric patients.

Source: Wikimedia Commons URL: https://commons.wikimedia.org/wiki/File:Diabetic_ketoacidosis.jpg License: CC BY-SA 4.0

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