Addison
Disease
Autoimmune
destruction of the adrenal gland
- usually
presents as slowly evolving
manifestations of deficiencies in cortisol, aldosterone, and sex steroid
hormones.
- anorexia,
weight loss, muscle weakness, and fatigue.
- GI: nausea,
vomiting, diarrhea, or abdominal pain
- blood
pressure may be low.
- may crave
salt.
- increased
pigmentation of the skin
-
accentuation of freckles
- dark
palmar creases
-
bluish-brown buccal mucosa
-
pigmentation of the skin over the extensor surfaces of the elbows and knees
- persistent
sun tan
Laboratory
findings that support the diagnosis of Addison disease:
- hypoglycemia
- hyponatremia,
hyperkalemia
- normochromic
anemia
- eosinophilia
The disease is
characterized by:
-
decreased level of cortisol and aldosterone
-
high adrenocorticotropic hormone (ACTH) level.
- The most
definitive diagnostic test is an ACTH stimulation test.
- resting
levels of cortisol are low, and there is no increase after intravenous
administration of ACTH.
- If there is
a need to differentiate prolonged adrenal suppression from ACTH deficiency, an
increase in urinary 17-hydroxycorticosteroid after
3 days of intramuscular ACTH
administration indicates adrenal reactivation, suggesting deficiency of either
ACTH or corticotropin-releasing factor. A lack of response confirms the
diagnosis of Addison disease.
Adrenal Crisis
-
if the slowly progressive deficiency is not recognized, an adrenal crisis may
develop
-
hypoglycemia, hyponatremia, hyperkalemia, acidosis, and hypotension that may
progress to shock
- Crises may
be precipitated by the stress
of:
- infection
- trauma
- surgery
-
medications, including thyroid hormone and insulin in both the unrecognized
patient or patients who have inadequate glucocorticoid replacement.
- Management
of an adrenal crisis requires
immediate intervention to prevent a fatal outcome.
-
Pretreatment blood samples
should be obtained to confirm the diagnosis
- serum
cortisol, ACTH
- renin,
aldosterone
-
Intravascular volume and renal perfusion must be restored with infusion of
0.9% saline plus sufficient glucose
to correct hypoglycemia.
-
Glucocorticoid replacement is administered as an intravenous bolus of
hydrocortisone sodium succinate.
- In patients
who have significant hyperkalemia (potassium level, >6 mEq/L [>6 mmol/L]),
careful electrocardiographic monitoring is necessary.
-
Administration of an oral resin of sodium polystyrene sulfonate (KayaxelateŽ)
also is recommended.
-
Dangerously high levels of potassium are treated with intravenous
10% calcium gluconate.
Addison disease
may occur as a part of the polyglandular autoimmune syndromes.
- Type I is
characterized by mucocutaneous candidiasis, hypothyroidism, and Addison
disease. It is an autosomal recessive disorder that involves chromosome 21 Q
22.3.
- Type II is
characterized by an autoimmune hypothyroidism, type 1 diabetes, and Addison
disease. Type II has been associated with human leukocyte antigen (HLA)-DR3
and HLA-DR4.
DDx
- Patients who
have anorexia nervosa and hyperthyroidism may present with weight loss and
menstrual cycle irregularities, but they would not have the skin pigment
changes reported for the girl in the
vignette.
- Late-onset
congenital adrenal hyperplasia and polycystic ovarian syndrome may present
with menstrual cycle irregularities andevidence of androgen excess, but the
clinical findings of hyperpigmentation should raise the suspicion of adrenal
cortisol deficiency.
- Acanthosis
nigricans, a slightly palpable, velvety hyperpigmentation in the
intertriginous areas of the body and neck, may be found in patients who have
polycystic ovarian syndrome and may indicate insulin resistance.
References:
August GP. Treatment of adrenocortical insufficiency. Pediatr Rev.
1997;18:59-62
Levine LS, DiGeorge AM. Adrenocortical insufficiency. In: Behrman RE,
Kliegman RM, Jenson HB, eds. Nelson Textbook of Pediatrics. 16th ed.
Philadelphia, Pa: WB Saunders Co; 2000:1725-1728