Addison's disease

Background

• Primary adrenal insufficiency
• Bilateral adrenal destruction by tuberculosis used to be most common cause, now only accounts for 7-20% of cases
• Autoimmune disease 70-90%, remainder caused by infectious disease, metastasis or lymphoma, adrenal hemorrhage, infarction, or drugs.
• Typically presents in adults between 30 and 50 years of age
  • All ages, races, genders can be affected
• Higher incidence with other autoimmune deficiencies

Clinical Presentation

• Abdominal pain
  • Chronic nausea, vomiting, diarrhea
• Weakness and fatigue
• Salt craving
• Abnormal skin pigmentation - will often look patchy
• Addisonian Crisis
  • Hypotension
  • Neurologic Symptoms: coma

Differential Diagnosis

• Corticosteroid withdrawal
• Secondary adrenal insufficiency - deficiency of ACTH (produced by the pituitary gland)
• Tertiary adrenal insufficiency - deficiency of CRH (produced by the hypothalamus)

Diagnosis

• Hypercalcemia
• Hypoglycemia
• Hyponatremia
• Hyperkalemia
• Metabolic Acidosis
  • Low stimulation of the renal distal tubule by aldosterone = sodium wasting in the urine and H+ retention
• Testing
  • ACTH stimulation test
    • Dexamethasone
      • Does not cross-react with the assay
      • Can be administered concomitantly during testing

Management

• Hormone Replacement
  • PO hydrocortisone and fludrocortisone

Disposition

• New Diagnosis: strong consideration for admission
• Crisis?: Consider admission based on electrolytes and clinical presentation

See Also

• Adrenal crisis