6- adrenal insufficiency

• Primary adrenal insufficiency (Addison disease)

  Destruction of the entire adrenal cortex, resulting in reduced glucocorticoid, mineralocorticoid and sex steroids. Major deficiencies are Na, steroid, and glucose.
• Causes of primary adrenal insufficiency

  • Autoimmune disease
  • Infectious diseases (tuberculosis, fungal infections, cytomegalovirus, cryptococcus, toxoplasmosis, pneumocystis)
  • Adrenoleukodystrophy
  • Hemorrhage/infarction (meningococcal septicemia)
  • Iatrogenic (bilateral adrenalectomy)
  • Infiltration (amyloid, malignant metastasis)
  • Polyglandular autoimmune syndromes 1 and 2 with other autoimmune conditions
• Secondary adrenal insufficiency

  Patients on long-term steroid therapy (most common cause), Hypopituitarism (rare)
• Tertiary adrenal insufficiency

  Hypothalamic disease
• Clinical features due to lack of cortisol

  • GI (anorexia, nausea, vomiting, abdominal pain, weight loss)
  • Mental symptoms (lethargy, confusion, depression, psychosis)
• Clinical features due to low aldosterone (only in primary adrenal insufficiency)

  • Hyponatremia & hypovolemia due to sodium loss
  • Postural hypotension, decreased cardiac output, decreased renal perfusion
  • Weakness, shock, syncope
  • Hyperkalemia (due to retention of potassium)
• Hypoglycemia occurs because cortisol is a gluconeogenic hormone
• Hyperpigmentation is common in primary adrenal insufficiency only, due to high ACTH (Low cortisol stimulates ACTH & MSH secretion)
• Pigmentations (grey-brown) especially in new scars, palmar creases and buccal area
• Acute adrenal crisis presents with profound hypotension, fever, confusion and coma
• Diagnosis

  1. Plasma cortisol level

  2. Standard ACTH test (Cosyntropin stimulation test)

  3. Plasma ACTH level

  4. Adrenal antibody: 21 hydroxylase

  5. Biochemical laboratory findings

  6. Plasma renin activity

  7. Imaging tests (MRI of brain, Chest and abdomen x-ray or CT)
• Management of acute adrenal crisis

  1. 1 L of 0.9% saline over 30-60 min with 100 mg of IV bolus hydrocortisone

  2. Glucose infusion if patient hypoglycemic

  3. Oral replacement medications once patient stabilized
• Long term management

  1. Primary adrenal insufficiency: daily oral glucocorticoid (hydrocortisone or prednisone) and daily fludrocortisone (mineralocorticoid)

  2. Secondary adrenal insufficiency: same as primary, except mineralocorticoid replacement not necessary