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).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