Diagnosis
The best diagnostic tool to confirm adrenal insufficiency is the ACTH stimulation test; however, if a patient is suspected to be experiencing an acute adrenal crisis, immediate treatment with IV corticosteroids is imperative and should not be delayed for any testing, as the patients health can deteriorate rapidly and result in death without replacing the corticosteroids.Dexamethasone should be used as the corticosteroid if the plan is to do the ACTH stimulation test at a later time as it is the only corticosteroid that will not affect the test results.If not performed during crisis, then labs to be run should include: random cortisol, serum ACTH, aldosterone, renin, potassium and sodium. A CT of the adrenal glands can be used to check for structural abnormalities of the adrenal glands. An MRI of the pituitary can be used to check for structural abnormalities of the pituitary. However, in order to check the functionality of the Hypothalamic Pituitary Adrenal (HPA) Axis the entire axis must be tested by way of ACTH stimulation test, CRH stimulation test and perhaps an Insulin Tolerance Test (ITT). In order to check for Addisons Disease, the auto-immune type of primary adrenal insufficiency, labs should be drawn to check 21-hydroxylase autoantibodies.
Other causes include; Infections (TB, CMV, histoplasmosis, paracoccidioidomycosis), vascular (hemorrhage from sepsis, adrenal vein thrombosis, HIT), deposition disease (hemochromatosis, amyloidosis, sarcoidosis), drugs (azole anti-fungals, etomidate (even one dose), rifampin, anticonvulsants)
Secondary adrenal insufficiency is caused by impairment of the pituitary gland or hypothalamus. Its principal causes include pituitary adenoma (which can suppress production of adrenocorticotropic hormone (ACTH) and lead to adrenal deficiency unless the endogenous hormones are replaced; secondary adrenal insufficiency can be caused by steroids, inhaled steroids such as Flovent; and Sheehans syndrome, which is associated with impairment of only the pituitary gland. Tertiary adrenal insufficiency is due to hypothalamic disease and a decrease in the release of corticotropin releasing hormone (CRH). Causes can include brain tumors and sudden withdrawal from long-term exogenous steroid use (which is the most common cause overall). Signs and symptoms
Signs and symptoms include: hypoglycemia, hyperpigmentation, dehydration, weight loss, and disorientation. Additional signs and symptoms include weakness, tiredness, dizziness, low blood pressure that falls further when standing (orthostatic hypotension), cardiovascular collapse, muscle aches, nausea, vomiting, and diarrhea. These problems may develop gradually and insidiously. Addisons disease can present with tanning of the skin that may be patchy or even all over the body. Characteristic sites of tanning are skin creases (e.g. of the hands) and the inside of the cheek (buccal mucosa). Goitre and vitiligo may also be present. Eosinophilia may also occur. Hyponatremia is a sign of secondary insufficiency.