Addison's disease

Background

Posterior view of the adrenal glands (colored) in relation to the viscera and large vessels of the abdomen (thoracic vertebra removed).

Types of adrenal insufficiency (primary, secondary, and tertiary) compared to normal physiology. In its normal state, the hypothalamus secretes corticotropin-releasing hormone (CRH) to induce the pituitary gland to secrete adrenocorticotropic hormone (ACTH) to induce the adrenal gland to secrete cortisol. Cortisol then exerts negative feedback by inhibiting the secretion of CRH and ACTH in the hypothalamus and pituitary gland, respectively.

• Primary adrenal insufficiency
• Autoimmune disease (70-90%)
  • Tuberculosis previously most common cause
  • Other causes include infectious, metastatic cancer, lymphoma, adrenal hemorrhage, infarction, 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 Features

A Caucasian woman with Addison's disease

• 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)

Adrenal crisis

• Addison's disease
• Congenital adrenal hyperplasia
• Shock
• Sepsis
• Pituitary apoplexy
• Sheehan's syndrome

Evaluation

Laboratory findings

• Hypercalcemia
• Hypoglycemia
• Hyponatremia
• Hyperkalemia
• Metabolic acidosis
  • Low stimulation of the renal distal tubule by aldosterone = sodium wasting in the urine and H+ retention

Evaluation

• Chemistry
• Random cortisol, renin, and ACTH levels
  • Do not wait for levels before starting treatment
• ACTH (cosyntropin) stimulation test

Management

• Hormone Replacement
  • PO hydrocortisone and fludrocortisone
• Adrenal crisis should be treated with 100mg hydrocortisone IV followed by 50mg IV q6 hours

Disposition

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

See Also

• Adrenal crisis