Emergency Inherited Inborn Errors of Metabolism

Addison's Disease (Adrenal Insufficiency)

Pediatric Primary Adrenal Insufficiency Syndrome

Primary risk age: School-aged children and adolescents (rare in infants, though congenital forms exist)

Urgency: Emergency
Typical age: School-aged children and adolescents (rare in infants, though congenital forms exist)
Body system: Endocrine & Metabolic

Typical course: This is a lifelong primary endocrine deficiency; continuous daily hormone replacement is required.

Reviewed against AAP · CDC · WHO · NHS guidance Last reviewed 2026-06-13

1. Summary & Pathophysiology

Pediatric Primary Adrenal Insufficiency Syndrome

Pathophysiology (Development Path)

Autoimmune or genetic destruction of the adrenal cortex leads to a progressive deficiency of glucocorticoids (cortisol) and mineralocorticoids (aldosterone). Deficient cortisol impairs glucose homeostasis, while deficient aldosterone impairs sodium reabsorption and potassium excretion in the kidneys.

Primary Causes & Etiology

Autoimmune destruction of the adrenal cortex (autoimmune adrenalitis), congenital adrenal hypoplasia, or adrenoleukodystrophy.

2. Symptom Continuum

Early Onset Signs
Slowly progressive fatigue, muscle weakness, salt cravings, and hyperpigmentation (darkening of skin creases, scars, and gums).
Progressive Phase
Anorexia, weight loss, chronic abdominal pain, nausea, vomiting, and recurrent orthostatic hypotension.
Severe Indicators
Adrenal Crisis: severe vascular collapse, refractory hypovolemic shock, hypoglycemia, hyperkalemia (high potassium), hyponatremia (low sodium), and cardiac arrhythmias.

3. Clinical Verification

Low morning cortisol and elevated ACTH levels. Confirmed by an ACTH stimulation test showing failure of cortisol to rise (<18 mcg/dL). Elevated plasma renin.

4. Care & Elements Plan

Primary Care Treatment Plan

Replace deficient hormones. Administer daily oral Hydrocortisone (glucocorticoid) and Fludrocortisone (mineralocorticoid). Implement a "Stress Dosing" plan (triple the steroid dose) during periods of fever, infection, surgery, or trauma.

Home Support Elements

Ensure the child carries medical alert identification. Keep an emergency Hydrocortisone injection kit at home and at school. Ensure adequate sodium intake during hot weather.

Generic Active Ingredients (No Brands)

Hydrocortisone (generic active glucocorticoid replacement ingredient)
Fludrocortisone acetate (generic active mineralocorticoid replacement ingredient).

Lists active elements only. Never administer self-designed therapies.

5. Doctor Critical Lines

Critical Thresholds: When to See a Doctor

Seek emergency evaluation immediately if a child with Addison's disease develops vomiting (unable to retain oral steroids), high fever, severe fatigue, or signs of shock.

6. Vaccine & Prevention

Routine Prophylaxis (Prevention)

No primary prevention exists for autoimmune adrenalitis or genetic adrenal disorders.

Immunization Context

Children on standard replacement doses of steroids (not immunosuppressive doses) can follow routine vaccination schedules; annual influenza vaccine is recommended.

7. Timelines & Outlook

Active Timeline

This is a lifelong primary endocrine deficiency; continuous daily hormone replacement is required.

Expected Prognosis

Excellent with strict compliance with hormone replacement and stress dosing protocols; children can live normal, active lives.

Potential Untreated Complications

Adrenal crisis, severe hypoglycemia, electrolyte shock, and developmental growth delays.

Severe

Phenylketonuria (PKU)

Inborn Error of Amino Acid Metabolism

Neonates (Screened at birth; symptoms develop over the first year if untreated)

Emergency

Classic Galactosemia

Inborn Error of Carbohydrate Metabolism

Neonates (Symptoms present within days of initiating milk feeding)