Sunday, September 4, 2011

Addisons disease (Chronic adrenal insufficiency, hypocortisolism, Hypocorticism)

Addison’s disease is a chronic rare condition in which the adrenal glands are not capable to produce sufficient steroid hormones needed for the body. The hormones produced by adrenal gland is glucocorticoids and mineralocorticoids. Addison’s disease is an endocrinal disorder which require lifelong steroid replacement therapy.

Addison’s disease is named after a British physician Thomas Addison who described the condition for the first time.

Epidemiology

Around one in 100,000 population is affected with Addison’s disease. Addison’s disease affects any age group, ethnicity or gender. It is seen mostly in adults between 30 to 50 years of age.

Signs and symptoms

Signs of Addison’s disease

The signs of Addison’s disease are insidious in nature which may take long time to recognize the disease. Most common signs are fatigue and weakness, light headedness on standing position, fever, headache, diarrhoea, mood changes, muscle pain and weakness and weight loss.

Clinical signs include low blood pressure, calcification of pinna of the ear, hyperpigmentation of the skin and medical conditions like thyroid disease, Diabetes mellitus (Type I), and vitiligo may occur together with Addison’s disease.

Signs of Addisonian crisis

Addisonian crisis occur when the adrenal insufficiency is severe enough to affect the normal body mechanism. It is a medical emergency and a life-threatening condition requiring immediate medical attention.

Signs of Addisonian crisis (Adrenal crisis) include Severe pain on legs, abdomen and back which is sudden in onset, Vomiting, diarrhoea and dehydration, loss of consciousness and inability to stand up, low blood pressure, Low blood sugar, Psychological problems, low sodium levels, increase in blood level of potassium, elevated calcium levels, fever and convulsions.

Causes

The main causes of Addison’s disease are

1. Developmental problem of the adrenal gland (Adrenal dysgenesis).

Adrenal dysgenesis is a developmental problem and is genetic. This is a very rare condition and include mutations of SFI transcription factor, DAX-I gene mutation etc.

2. Biochemical problems of the gland leading to inability to produce the cortisol

Adrenal glands require cholesterol to produce cortisol and any condition resulting in impairment in availability of cholesterol leads to this condition.

3. Disease of the adrenal gland resulting in destruction of the gland

The most common cause of adrenal gland destruction is the auto immune adrenalitis caused by the immune reaction against the enzyme 21-hydroxylase. Cancer, Haemorrhage and infections are also the causes of adrenal destruction.

Diagnosis

Blood test: reveals Hypercalcemia (Increase in calcium levels in blood), low blood sugar, low sodium levels, high potassium levels, Eosinophilia (increased number of white blood cells), increased acidity of blood (metabolic acidosis) etc.

ACTH stimulation test: In this test a manual stimulation to the adrenal glands is given and in presence of Addison’s disease, adrenal hormones will be below normal even with the stimulation of the gland.

Other tests: Estimation of rennin and adrenocorticotropic hormone levels and imaging techniques like MRI will reveal the cause of hypoadrenalism.

Treatment

Replacement

Hormone replacement is an important treatment in Addison’s disease. Cortisol must be replaced according to the body requirements. Hydrocortisone tablets are used to supply cortisol required by the body. Sometimes prednisolone may be used instead of hydrocortisone to mimic the effect of it on the body.

Crisis management:

When the body does not have adequate supply of cortisol Adrenal crisis occurs. This is managed by administering large doses of saline solution with glucose and glucocorticoids. As the condition of the patient improves, dose of glucocorticoid is decreased gradually.
Recovery

With proper treatment a patient with Addison’s disease can lead a normal life. It is important to carry an identification card stating that the person has the disease will help to provide immediate medical attention at the time of Adrenal crisis. Patient should carry the medication while travelling. With all these precautions, patient can lead a quality life.

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