Adrenal insufficiency

Today we discussed adrenal insufficiency. Some of the main points:

From the 1849 original description of Thomas Addison, which describes most of the key clinical features:

"The leading and characteristic features of the morbid state to which I would direct attention, are, anæmia, general languor and debility, remarkable feebleness of the heart’s action, irritability of the stomach, and a peculiar change of colour in the skin, occurring in connexion with a diseased condition of the supra-renal capsules."

Adrenal insufficiency may be primary (i.e. an adrenal problem) or secondary (i.e. a pituitary problem).

Causes of primary insufficiency (not exhaustive!)
1) Autoimmune (sometimes associated with polyglandular autoimmune syndromes- I or II)
2) Granulomatous (TB, histoplasmosis, coccidiomycosis, cryptococcosis, sarcoidosis)
3) Other infections (meningococcemia, CMV, HIV, MAI)
4) Medications (ketoconazole, etomidate, phenytoin, rifampin...)
5) Bilateral hemorrhage
6) Adrenal metastases
7) Congenital (e.g. adrenoleukodystropy)

Common clinical manifestations
Weakness, hyperpigmentation, weight loss, anorexia, nausea, vomiting, BP below 110/70

A word on the hyperpigmentation:
diffuse, brown, tan, or bronze darkening of creases, elbows, and normally more pigmented areas (areolae, perineum). Also may see bluish-black patches on mucous membranes.

Lab findings:
May see hyponatremia, hyperkalemia, lymphocytosis, eosinophilia, mild hypercalcemia, hypoglycemia.
In primary, low cortisol, high ACTH. May have normal random cortisol, so stimulation test is more sensitive.

Primary vs. secondary:
May see associated pituitary hormone deficiency manifestations or signs of compression from pituitary mass in secondary. Hyperpigmentation does not occur in secondary. Hyponatremia, but not hyperkalemia, occurs in secondary (no mineralocorticoid deficiency).

Treatment:
Acutely, hydrocortisone 100mg IV q8h +/- fludrocortisone (usually not needed acutely because hydrocortisone has minaralocorticoid effect). Maintenance doses as soon as patient is over crisis. Supportive care otherwise (fluid resuscitation, etc.).
Chronically, may start with doses like hydrocortisone 20mg qAM, 10mg qPM
fluorinef 0.1mg PO OD

Some links:

Click here for a recent NEJM review article

Click here for Addison's original description from 1849