Adrenal Disorders

Adrenal Gland Overview - Hormone Factory Tour

• Paired glands, superior to kidneys; retroperitoneal.
• Two main parts:
  • Outer Adrenal Cortex: Produces corticosteroids.
  • Inner Adrenal Medulla: Produces catecholamines.
• Adrenal Cortex Layers (Outer to Inner): 📌 Mnemonic: GFR → Salt, Sugar, Sex.
  • Zona Glomerulosa: Mineralocorticoids.
  • Zona Fasciculata: Glucocorticoids.
  • Zona Reticularis: Androgens.

⭐ The adrenal cortex has three zones: Zona Glomerulosa (Mineralocorticoids - Aldosterone), Zona Fasciculata (Glucocorticoids - Cortisol), and Zona Reticularis (Androgens - DHEA).

• Adrenal Medulla:
  • Key hormones: Epinephrine, Norepinephrine.
  • Role: Mediates "fight or flight" stress response.

CAH - Enzyme Glitch Mayhem

Autosomal recessive disorders of adrenal steroidogenesis.

• 21-Hydroxylase Deficiency (90-95%): Most common.
  • ↓Cortisol, ↓Aldosterone, ↑Androgens.
  • Salt-Wasting (SW): Neonatal: vomiting, dehydration, ↓Na, ↑K. Ambiguous genitalia (XX). Most severe.
  • Simple Virilizing (SV): Ambiguous genitalia (XX); precocious puberty (XY). Normal electrolytes.
  • Non-Classical (NC): Late: hirsutism, acne, oligo/amenorrhea.
  • Dx: ↑17-OHP (17-hydroxyprogesterone).
• 11β-Hydroxylase Deficiency (5-8%):
  • ↓Cortisol, ↑Androgens, ↑11-deoxycorticosterone (DOC) → Hypertension.
  • Virilization.
• 17α-Hydroxylase Deficiency (Rare):
  • ↓Cortisol, ↓Androgens, ↑DOC → Hypertension.
  • XX: Sexual infantilism. XY: Pseudohermaphroditism.

⭐ Salt-wasting 21-hydroxylase deficiency CAH presents in neonates with vomiting, dehydration, hyponatremia, and hyperkalemia; females show ambiguous genitalia.

Treatment: Glucocorticoids (hydrocortisone), Mineralocorticoids (fludrocortisone if SW).

Adrenal Insufficiency - Power Down Protocol

• Types: Primary (adrenal failure, e.g., CAH, Addison's), Secondary (↓ACTH), Tertiary (↓CRH).
• Adrenal Crisis: Life-threatening! Hypotension, shock, hypoglycemia, ↓Na, ↑K.

  ⭐ In suspected adrenal crisis, do NOT wait for diagnostic tests; administer IV/IM hydrocortisone immediately. Dose: Neonates 25mg, Infants 25-50mg, Children 50-100mg.

• Chronic AI Features: Weakness, fatigue, weight loss. Primary: hyperpigmentation, salt craving.
• Diagnosis: ↓AM cortisol. ACTH stimulation test (cortisol fails to rise in primary). Plasma ACTH (↑ primary, ↓ secondary/tertiary).
• Management:
  • Crisis: IV Hydrocortisone, IV fluids (NS/D5NS), correct hypoglycemia.
  • Chronic: Hydrocortisone; Fludrocortisone (if primary AI). Stress doses for illness.

Adrenal Hormone Overload - Surplus States Saga

• Cushing's Syndrome (Hypercortisolism):
  • Causes: Iatrogenic (steroids), Pituitary (Cushing's disease), Adrenal (adenoma/carcinoma), Ectopic ACTH.
  • Features: Central obesity, moon facies, purple striae, HTN, ↑glucose, proximal myopathy.
  • Dx: Dexamethasone Suppression Test (DST), 24hr Urine Free Cortisol (UFC), late-night salivary cortisol.

  • ⭐ The dexamethasone suppression test is key in diagnosing Cushing's syndrome; failure to suppress cortisol suggests autonomous cortisol production.

• Conn's Syndrome (Primary Hyperaldosteronism):
  • Cause: Adrenal adenoma or bilateral hyperplasia → ↑Aldosterone, ↓Renin.
  • Features: HTN (often resistant), hypokalemia (muscle weakness, polyuria), metabolic alkalosis.
  • Dx: Aldosterone-Renin Ratio (ARR) > 20; saline/fludrocortisone suppression test.
• Pheochromocytoma (Catecholamine Excess):
  • Tumor of adrenal medulla chromaffin cells.
  • Features: "PHE" - Palpitations, Headache, Episodic sweating; paroxysmal HTN.
  • 📌 Rule of 10s: 10% bilateral, 10% extra-adrenal, 10% malignant, 10% pediatric, 10% familial (some overlap).
  • Dx: 24hr urine/plasma metanephrines & normetanephrines; VMA less sensitive.

High‑Yield Points - ⚡ Biggest Takeaways

• CAH: Most common is 21-hydroxylase deficiency; causes ambiguous genitalia (girls), salt-wasting. Newborn screening (elevated 17-OHP) is essential.
• Adrenal Insufficiency: Presents with hypoglycemia, hypotension, hyperpigmentation. Stress dose steroids are critical during illness.
• Cushing's Syndrome: Often iatrogenic or due to adrenal tumor; features moon facies, central obesity, and growth failure.
• Pheochromocytoma: Rare tumor causing paroxysmal hypertension, headache, sweating. Diagnose with urinary metanephrines.
• Primary Hyperaldosteronism: Characterized by hypertension and hypokalemia.