Addison's disease

April 2017


Definition


Addison's disease is an endocrine disease, i.e. related to an endocrine gland that secretes hormones. It is a chronic adrenal insufficiency. This means that the adrenal glands do not secrete enough hormones, causing various clinical signs as a result. The adrenal gland secretes mainly two types of hormones: glucocorticoids, upon stimulation of the pituitary gland, and mineralocorticoids, which are a main part of aldosterone. Historically, Addison's disease was a term characterizing the infection of adrenal gland by tuberculosis, but now this term includes all causes of chronic adrenal insufficiency. There are two types of decreased adrenal activity: in the first case, the infringement is central, that is to say, it comes from the brain and affects the pituitary gland that stimulates the adrenal glands: this is called HPA failure, because only hormones derived from cortisol are deficient. In the second case, the anomaly is peripheral, and it is the adrenal gland that fails directly: the secretion of hormones derived from cortisol is deficient but also that of mineralocorticoid hormones. This distinction is important for the diagnosis and treatment.
Addison's disease, or chronic adrenal insufficiency, due to tuberculosis has become rare, and what we see more frequently today is a cortical autoimmune disease. Genetic disease, drug-induced disorders, cancer, adrenal hemorrhaging, and infection may also be involved.

Symptoms


Common symptoms are:
  • change in skin pigmentation, tanned skin color;
  • severe fatigue, increased in the late afternoon;
  • occasionally, depression;
  • a decrease in blood pressure, which can lead to discomfort;
  • loss of appetite with weight loss;
  • occasionally, abdominal pain and vomiting, of which you should be wary in a person who is adrenal insufficient, because it may suggest a worsening of the disease.

Diagnosis


The diagnosis is made with practice of blood tests:
  • measuring of ACTH, the pituitary hormone that stimulates the secretion of the adrenal glands, which is increased in case of Addison's disease;
  • measuring of cortisol, always levied at 8:00 in the morning, since the rate varies significantly during the day;
  • measuring of aldosteron, which is also reduced;
  • sometimes, in case of doubt, a special test called Synacthen® confirms the presence of Addison's disease with certainty.

Additional tests are then done to find the cause of the disease:
  • measuring of antibodies in the blood;
  • a chest X-ray, which looks for signs of tuberculosis;
  • a CT scan that allows to study the adrenal glands.

Treatment


To overcome hormone deficiency, synthetic molecules are given to the patient: both glucocorticoids and mineralocorticoids. The treatment of Addison's disease also requires an "education" of the patient, because this disease can become severe if instructions are not followed: treatment must be taken carefully, food should not be too high in salt, no medication should be taken without a doctor's approval, and any abnormal signs should be quickly checked out by a doctor: fever, abdominal pain or vomiting, loss of consciousness...

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Original article published by . Translated by Jeff. Latest update on July 1, 2013 at 01:09 PM by Jeff.
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