Congenital adrenal hyperplasia

Background

Steroidogenesis: The enzymes affected in CAH are represented by one red and four green bars on the top half of the diagram (for example, "21α-hydroxylase" is visible near the top center. "17α-hydroxylase" and "17,20 lyase" are carried out by a single enzyme).[29] Depending upon which enzyme is unavailable, production of androgens (lower left) or mineralocorticoids (upper right) is reduced. This, in turn, can lead to increased production of other molecules, due to a buildup of precursors.

• 95% of cases due to deficiency of 21-hydroxylase
  • Leads to cortisol deficiency, aldosterone deficiency, virilization
• Patients present during 2nd-5th week of life in crisis
• Although congenital adrenal hyperplasia is part of the normal neonatal screening, results might not be available for 3 to 4 weeks.

Clinical Features

Clitoromegaly (with normal labia and introitus) in a female child with CAH.

• Patient presents in 2nd week of life in crisis
  • Lethargy, irritability, poor feeding, vomiting, dehydration, shock
• Salt-wasting
  • Hyponatremia, hyperkalemia
• Virilization: The development of male-pattern physical traits in females
• Brown hue skin color
• Partial CAH may present later and less dramatically with irregular menses in adolescence

Differential Diagnosis

• Adrenal salt-wasting crisis

Sick Neonate

THE MISFITS

• Trauma
• Heart
  • Congenital heart disease
  • Hypovolemia
• Endocrine
  • hypoglycemia
  • Hypothyroidism
  • Congenital adrenal hyperplasia
• Metabolic
  • Sodium
  • Calcium
  • Glucose
• Inborn errors of metabolism
• Seizure
• Formula / feeding problems
  • Hyponatremia
  • Hypocalcemia
  • FPIES / Food protein-induced enterocolitis syndrome
• Intestinal Disasters
  • Duodenal atresia
  • Midgut volvulus
  • Necrotizing enterocolitis
  • Intussusception
• Toxin
• Sepsis

Adrenal crisis

• Addison's disease
• Congenital adrenal hyperplasia
• Shock
• Sepsis
• Pituitary apoplexy
• Sheehan's syndrome

Evaluation

Work-Up

• Bedside glucose
• Chemistry
  • Hyponatremia
  • Hyperkalemia - rarely causes cardiac dysfunction

Management

• NS 10-20mL/kg bolus 0.9% saline solution or 5% dextrose in normal saline
  • Hypotonic saline or 5% dextrose without addition of NS should not be used as can worsen hyponatremia
• Steroid replacement
  • Neonates: Hydrocortisone 25mg IV/IO
  • Obtain blood sample for steroid hormone measurement
    • Most importantly 17-OHP (17-hydroxyprogesterone) to evaluate for 21-hydroxylase deficiency prior to administering hydrocortisone
• Hypoglycemia
  • If significant hypoglycemia, given IV bolus 5-10mL/kg of 10% dextrose (0.5-1.0 g/kg) or 2-4mL/kg of 25% dextrose (D25) infused slowly at rate of 2-3 mL/min
• Hyperkalemia
  • Typically improves promptly after hydrocortisone
  • Rare occasionally for severe and symptomatic hyperkalemia, administration of glucose and insulin is needed to manage hyperkalemia

Disposition

• Admit

See Also

• Adrenal Crisis