Addison's Disease
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More Specific Terms
Introduction
- Addison's disease (primary adrenal failure) is caused by deficiency of cortisol with or without deficiency of aldosterone.
Etiology
- tuberculosis
- mycosis, especially histoplasmosis
- AIDS-associated
- hemorrhagic adrenal infarction
- precipitating factors
- symptoms
- abdominal or flank pain
- fever
- lymphoma
- leukemia
- lung cancer
- breast cancer
- rarely cause enough adrenal destruction to result in adrenal insufficiency [4]
- bilateral adrenalectomy
- sarcoidosis
- adrenoleukodystrophy
- pharmaceutical agents
- recent discontinuation of corticosteroid therapy, & up to 1 year after corticosteroid withdrawal
- failure to increase chronic corticosteroid therapy in times of stress
- agents that inhibit steroid synthesis
- ketoconazole
- adrenolytic agents
- etomidate
- metyrapone
- agents that induce cortisol metabolism
- pituitary or hypothalamic pathology
Pathology
- 90% of adrenal must be destroyed before adrenal failure occurs
- secretion of cortisol, aldosterone & DHEA affected
- glucocorticoid deficiency
- decreased cardiac stroke volume
- heart rate increases
- cardiac output declines
- vasopressin is released
- free water retention
- inhibition of catecholamine activity
- diminished peripheral vascular resistance
- hypotension
Clinical-manifestations
- general manifestations of glucocorticoid deficiency
- weakness & fatigue
- weight loss
- diffuse musculoskeletal pain, arthralgia
- orthostatic hypotension
- dehydration
- auricular calcifications
- symptoms of hypoglycemia
- salt-craving
- skin manifestations
- mottled skin pigmentation ( hyperpigmentation due to ACTH secretion)
- buccal mucosa (Caucasians)
- lips, gingival margins, buccal mucosa
- elbows, knees, knuckles, palmar creases, scars
- vagina, rectum
- vitiligo suggests autoimmune etiology
- anorexia or aversion to food
- nausea & vomiting
- abdominal pain
- diarrhea
- psychiatric manifestations
- manifestations of mineralocorticoid deficiency
- salt craving
- orthostatic hypotension or syncope
- manifestations of androgen deficiency in women
- decreased body hair, decreased pubic & axillary hair
- amenorrhea
Laboratory
-
- serum chemistries
- low serum Na+
- low serum Cl-
- low serum HCO3-
- high serum K+
- hypercalcemia, generally mild to moderate
- fasting hypoglycemia
- azotemia
- low urinary 17-ketosteroids, high urinary 17-hydroxysteroids
- low 24 hour urinary free cortisol
- generally low, but generally not useful
- only 50% of patients with adrenal insufficiency have diagnostic morning serum corticol of > 3 ug/ dL
- in the presence of severe physiologic stress, serum cortisol < 20 ug/ dL suggests adrenal insufficiency
- random serum cortisol > 20 ug/ dL excludes adrenal insuffiency
- markedly elevated in primary adrenal insufficiency
- low or inappropriately normal in secondary adrenal insufficiency
- plasma renin high
- cosyntropin ( Cortrosyn) stimulation test - test of choice
- a rise in serum cortisol of > 23 ug/ dL rules out adrenal insufficiency
- gold standard for evaluation of the hypothalamic- pituitary-adrenal axis
- hazardous test
- PPD -> if tuberculosis is a possible etiology
Radiology
- calcification of adrenals is rarely observed
- computed tomography (CT) of adrenal glands
- indicated if serum ACTH is elevated
- autoimmune adrenalitis leads to small adrenal glands
- infection, hemorrhage & other causes lead to large adrenal glands
- MRI of the brain ( sella tursica) if serum ACTH is low or normal
Management
- hydrocortisone (12-15 mg/m2 daily)
- double the oral maintenance dose
- for severe illness or injury
- hydrocortisone 100-150 mg/day IV divided every 6 hours
- septic shock: 150-200 mg/day [4]
- do not use dexamethasone for chronic glucocorticoid replacement therapy [4]
- fludrocortisone ( Florinef) 0.05-0.1 mg PO qAM
- primary adrenal insufficiency
- higher doses may be needed if prednisone is used
- liberalized salt intake
- patient education
- Medic alert bracelet
- patients should have & be instructed on use of parenteral glucocorticoids in case of emergency
- follow-up
- glucocorticoid replacement
- appetite, well-being, body weight are the best indicators to follow
- serum ACTH, cortisol & electrolytes do not reflect clinical status & do not need to be monitored
- signs of Cushing's syndrome suggest over-replacement
- bone mineral density measurements should be performed periodically
- mineralocorticoid replacement
- plasma renin activity is the best indicator of plasma volume & should be titrated to the upper normal range
- serum K+ levels should be monitored
- blood pressure should be checked frequently
- recumbent hypertension is a problem in patients taking fludrocortisone
More General Terms
Additional Terms
- 17 hydroxycorticosteroid
- 17 ketosteroid
- aldosterone (Electrocortin, Aldocortin)
- congenital adrenal hypoplasia
- cortisol; hydrocortisone (Cortef, Solu-Cortef, Alphaderm, Cetacort, Cortenema, Hytone, Nutracort, Westcort)
- cosyntropin (ACTH, Cortrosyn) stimulation test (delta cortisol test)
- hypoglycemia
- insulin tolerance test (ITT)
- potassium (K+) in serum/plasma
- renin (angiotensinogenase)
References
- Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 474
- DeGowin & DeGowin's Diagnostic Examination, 6th edition, RL DeGowin (ed), McGraw Hill, NY 1994, pg 862
- Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 653-656
- Medical Knowledge Self Assessment Program (MKSAP) 11, 14, 15 American College of Physicians, Philadelphia 1998, 2006, 2009
- Addison's Disease: NIH Institute and Center Resources [1]
