Primary adrenal insufficiency

From IDWiki

Background

Etiology

Risk Factors

Clinical Manifestations

Adrenal Insufficiency

  • Fatigue, weight loss, postural dizziness, anorexia, abdominal discomfort
  • Hyperpigmentation (primary only), particularly of sun-exposed areas, skin creases, mucosal membranes, scars, and areola, low blood pressure with postural drop, failure to thrive (in children)
  • Labs may show hyponatremia, hyperkalemia and, occasionally, hypoglycemia (especially in children) or hypercalcemia

Adrenal Crisis

  • Severe weakness, syncope, abdominal pain, nausea, vomiting, back pain, confusion
  • Hypotension, abdominal tenderness or guarding, altered consciousness, delirium
  • Hyponatremia, hyperkalemia, hypoglycemia, hypercalcemia

Differential Diagnosis

  • Adrenal suppression with mitotane, ketoconazole, metyrapone, etomidate
  • Increased cortisol metabolism with mitotane, phenytoin, carbamazepine, and St. John's wort

Diagnosis

  • A single baseline ACTH and cortisol, ideally morning
    • Cortisol is 80% bound to CBG (increased by estrogen, pregnancy, mitotane) and 10-15% bound to albumin
  • Corticotropin stimulation test
    • Get ACTH (will tell you if ACTH-dependent or -independent), baseline cortisol, +/-  aldosterone
    • Give Cosyntropin 0.25 mg IM/IV
    • Check cortisol at 30 minutes and 60 minutes
    • A normal test is if cortisol rises to a peak of 500-550 nmol/L by 60 minutes