Addison's Disease in MRCP

Addison’s disease in MRCP

OK, today I am going to talk about one condition which is important in two ways, Addison’s disease is an important endocrine condition because,

1) It is a popular condition in your MRCP examination,
2) It is important clinically because the mortality is high if you do not pick it up fast in clinical practice especially if patients present with acute Addison's crisis!

Adrenal insufficiency can be due to dysfunction of the adrenal gland itself ( primary- Addison’s Disease) or due to disordered pituitary or hypothalamus function ( secondary)

I think we will cover Addison’s disease today and you can forget about secondary Adrenal insufficiency because it is rather rare.

Addison’s disease refers to primary failure of the adrenal gland leading to loss of production of glucocorticoids and mineralcorticoids.

Causes of Addison’s disease

1) Always remember that it is mainly due to autoimmune adrenalitis and it is associated with Polyglandular autoimmune syndrome. ( Never get yourself confused this with Multiple Endocrine Neoplasia, MEN)
Remember as well that you may find antibodies against the 21-hydroxylase enzyme in 90% of autoimmune cases.

2) Tuberculosis

3) Distant metastasis

Signs and symptoms

As I remember as a medical student, there are 3 main medical causes( non-surgical causes) of abdominal pain, of course Addison’s disease is one of them. The other two are Diabetic ketoacidosis and intermittent Porphyria. ( Always remember this and later you will realize that it is very common for your friends in A+E missing diabetic ketoacidosis simply because patients present with abdominal pain)

Other symptoms include lethargy, nausea and vomiting, dizziness.

Important signs to look for are
1) hyperpigmentation ( it is a popular case in MRCP PACES as well) and I hope you know the reason behind this.
2) postural hypotension
3) loss of body hair ( due to reduced production of androgen)

Investigations
Remember the important clues to look for are
1) Low Sugar
2) Low Sodium
3) High Potassium
------- SSP. Patient may present with fever as well.

Diagnosis

Synacthen test. I think you do not need to know the details and the values. Just know the principles, in normal people, cortisol level will increase significantly after synacthen ( ACTH) stimulation but for Addison’s disease, since there is primary failure of adrenal gland, it will not be stimulated to produce more cortisol after synacthen.

Management

Remember that acute Addsison’s crisis is a medical emergency and it is usually due to prolonged adrenal suppression secondary to exogenous drugs such as steroids.

For chronic Addison’s disease, supplement patients with glucocorticoid ( hydrocortisone) and mineralcorticoid ( fludrocortisone)

Tips for MRCP

You may give a case in your MRCP Part 2 where you are given some electrolytes imbalances in a patient who presents to A+E due to abdominal pain.