Primary Adrenal Insufficiency

Causes

  • autoimmune
  • cancer mets/lymphoma
  • infection
  • bleeding, infarct
  • adrenoleukodystrophy
  • CAH

Workup

  • low cortisol, high ACTH, can use Cosyntropin stimulation test
  • most common cause: autoimmune adrenalitis
    • destruction of all layers of adrenal cortex
    • positive 21-hydroxylase antibodies in 90% of cases
    • associated with other autoimmune endocrine disorders: celiac, hypothyroidism, hypoparathyroidism, DM, ovarian insufficiency, autoimmune gastritis
  • If 21-hydroxylase antibody measurement is negative, abdominal CT imaging should be performed.
    • Autoimmune disease: atrophic adrenal glands, although normal-sized adrenal glands do not rule out this diagnosis.
    • Other causes of cause enlargement of the adrenal glands. These include infiltrative disorders such as lymphoma, sarcoidosis, histoplasmosis, or tuberculosis (the latter can be associated with normal-sized adrenal glands).
    • Bilateral adrenal hemorrhage can present as acute adrenal insufficiency and should be considered if unexpected hypotension develops. Risk factors for bilateral adrenal hemorrhage include protein C deficiency, anticoagulation, disseminated intravascular coagulopathy, and sepsis.
    • Metastatic disease to the adrenal glands rarely causes adrenal insufficiency if both glands involved.

Treatment

Preferred treatment for glucocorticoid:

  • hydrocortisone 2/2 shorter duration of action
  • total daily dose: 15 to 25 mg divided into bid/tid
  • 15mg in am and 5 mg in afternoon or three times daily
  • prednisone once daily in am can be used as substitute
  • dexamethasone: long duration of action can cause more side effects, not used Preferred mineralcorticoid treatment:
  • fludrocortisone once a day