Addison’s disease is a chronic clinical disease characterized by the progressive decline in the function of the adrenal glands. This potentially fatal disease may result in hyperpigmentation, hypotension, and cardiovascular collapse. Addison’s disease is easily diagnosed clinically and by the use of hormonal assays that reveal an elevated adrenocorticotropic hormone (ACTH) with a low plasma cortisol level.
On occasions, the symptomatology of Addison’s disease may appear acutely or abruptly. The acute onset of adrenal insufficiency symptoms is clinically referred to as Addisonian crisis. The following signs and symptoms are typically observed in acute adrenal failure:
Addison’s disease is primarily investigated by means of an extensive clinical history taking followed by a careful review of the presenting signs and symptoms. When the patients are suspected of having Addison’s disease the following confirmatory tests may be done to ascertain the diagnosis:
The main goal in the treatment of Addison’s disease is to replace the deficient hormones in the right levels of steroid hormones that the adrenal glands are incapable of maintaining. The following are options used in the treatment of Addison’s disease:
The greater majority of cases of Addison’s disease or primary adrenal insufficiency is caused by the idiopathic atrophy of the adrenals, accounting for almost 70% of all cases. The leading theory postulated for the idiopathic atrophy of the adrenals points to an autoimmune origin. There are however, some less common causes of adrenal destruction which include granuloma, tuberculosis, histoplasmosis, amyloidosis, inflammatory necrosis, hemorrhage and tumorous growths. The most common cause of Addison’s disease among children is congenital adrenal hyperplasia (CAH).
In the United States, the recent prevalence rate of Addison’s disease is up to 60 cases per one million population. Addison’s disease is relatively rare internationally. The increase in the mortality and morbidity rates is usually due to the delay in the replacement therapy of the mineralocorticoid and glucocorticoid hormones . Although, primary adrenal insufficiency is already considered serious and potentially life threatening, concomitant illnesses like malignancies, cardiovascular diseases, and infectious diseases influences greatly the increased mortality rate among these patients .
The primary idiopathic and autoimmune form of Addison’s disease is more commonly seen in children and females. There is no racial predilection to Addison’s disease. The mean age of onset is 30 to 50 years old but may present earlier among the infantile cases of congenital adrenal hyperplasia.
The pathogenesis of Addison’s disease or adrenal insufficiency is primarily due to the destruction of the adrenal cortex. Cortical destruction may either be inflammatory, necrotic, neoplastic, infectious, or hemorrhagic in nature. Signs and symptoms of adrenal insufficient usually present clinically when 90% or more of the adrenal cortex has been rendered dysfunctional or destroyed. The main systemic pathology is brought about by the lack of glucocorticoid and mineralocorticoid hormone secretion that is essential to the body.
Addison’s disease is a serious disorder that occurs when the adrenal glands are unable to produce sufficient hormones needed for proper metabolism. In this disorder, the hormones aldosterone and cortisol are insufficiently secreted from the suprarenal glands. For this reason, Addison’s disease is also referred to as primary adrenal insufficiency . Hormonal treatment is the standard approach to this disease to mimic the natural function of the deficient adrenal hormone.
The most common cause of Addison’s disease is idiopathic autoimmune adrenal atrophy. The other causes include granuloma, tuberculosis, histoplasmosis, amyloidosis, inflammatory necrosis, hemorrhage and tumors.
Patients usually present with anorexia, nausea and vomiting. Muscular fatigue and weakness are fairly common with hyperpigmentation of the skin. Signs of hypotension and hypoglycemia may also be observable.
Diagnostics for Addison’s disease starts with blood test of electrolytes and hormones. ACTH stimulation tests and Insulin-induced hypoglycemia tests, imaging studies with CT scan and MRI may follow.
Treatment and follow-up
The cornerstone in the treatment of Addison’s disease is the active hormonal replacement of the deficient hormones. Glucocorticoids are replaced with oral and injectable steroids, mineralocorticoids are replace by fludrocortisone. Androgen replacement therapy for afflicted women can allay the signs of androgen deficiency.