Addison's Flashcards
also known as primary adrenal insufficiency and hypocortisolism, is a long-term endocrine disorder in which the adrenal glands do not produce enough steroid hormones.[1] Symptoms
abdominal pain, weakness, and weight loss.[1] Darkening of the skin in certain areas may also occur.[1] Under certain circumstances, an adrenal crisis may occur with low blood pressure, vomiting, lower back pain, and loss of consciousness.[1] An adrenal crisis can be triggered by stress, such as from an injury, surgery, or infection.[1
Symptoms
Sudden penetrating pain in the legs, lower back, or abdomen
Severe vomiting and diarrhea, resulting in dehydration
Low blood pressure
Syncope (loss of consciousness and ability to stand)
Hypoglycemia (reduced level of blood glucose)
Confusion, psychosis, slurred speech
Severe lethargy
Hyponatremia (low sodium level in the blood)
Hyperkalemia (elevated potassium level in the blood)
Hypercalcemia (elevated calcium level in the blood)
Convulsions
Fever
Investigations
In suspected cases of Addison’s disease, demonstration of low adrenal hormone levels even after appropriate stimulation (called the ACTH stimulation test or synacthen test) with synthetic pituitary ACTH hormone tetracosactide is needed for the diagnosis. Two tests are performed, the short and the long test. Dexamethasone does not cross-react with the assay and can be administered concomitantly during testing.
The short test compares blood cortisol levels before and after 250 micrograms of tetracosactide (intramuscular or intravenous) is given. If, one hour later, plasma cortisol exceeds 170 nmol/l and has risen by at least 330 nmol/l to at least 690 nmol/l, adrenal failure is excluded. If the short test is abnormal, the long test is used to differentiate between primary adrenal insufficiency and secondary adrenocortical insufficiency.
The long test uses 1 mg tetracosactide (intramuscular). Blood is taken 1, 4, 8, and 24 hr later. Normal plasma cortisol level should reach 1000 nmol/l by 4 hr. In primary Addison’s disease, the cortisol level is reduced at all stages, whereas in secondary corticoadrenal insufficiency, a delayed but normal response is seen.
Other tests may be performed to distinguish between various causes of hypoadrenalism, including renin and adrenocorticotropic hormone levels, as well as medical imaging - usually in the form of ultrasound, computed tomography or magnetic resonance imaging.