Endocrine: Addisons

Question 1

What two hormones are affected in Addisons?

Answer 1

Cortisol and aldosterone

Question 2

Where are cortisol and aldosterone made?

Answer 2

Adrenal cortex

Question 3

Causes of addisons?

Answer 3

• Autoimmune: most common
• Infections: TB used to be most common cause
• Genetic disorders: CYP21A2 (congenital adrenal hyperplasia) and AIRE (APS-1) mutations
• Metastatic infiltration: e.g. lung, breast, or melanoma mets
• Adrenal Hemorrhage: trauma/anticoags
• Long term steroid use

Question 4

Low cortisol symptoms in addisons?

Answer 4

Cortisol: maintains glucose homeostasis, immune function, and stress response.

Reduced cortisol: hypoglycemia, increased susceptibility to infections, and an inadequate response to stressors.

Question 5

Low aldosterone symptoms in addisons?

Answer 5

Aldosterone: responsible for regulating sodium and potassium balance.

Insufficient aldosterone: hyponatremia, hyperkalemia, and volume depletion –> orthostatic hypotension and impaired renal function

Question 6

What causes the hyperpigmentation in addisons?

Answer 6

Increased ACTH secretion from the pituitary gland result in melanocyte-stimulating hormone (MSH) production, causing the characteristic hyperpigmentation seen in patients with Addison’s disease.

Question 7

Symptoms and management of addisonian crisis?

Answer 7

Symptoms:
Severe hypotension, hypoglycemia, pyrexia and altered mental status.

Management:
Immediate treatment with intravenous hydrocortisone, fluids, and electrolyte correction

Question 8

Main symptoms of addisons?

Answer 8

-HYPERS: Hyperpigmentation, Hyperkalaemia
- HYPOS: Hypotension, hypoglycaemia, hyponatraemia

• Lethargy/weakness
• Anorexia, nausea & vomiting, weight loss
• Salt-craving
• Vitiligo
• Loss of pubic hair in women

Question 9

Investigations for addisons

Answer 9

Short synacthen test - ACTH Stimulation Test
- Plasma cortisol is measured before and 30 minutes after giving Synacthen 250ug IM.

Bloods: Adrenal autoantibodies such as anti-21-hydroxylase may also be demonstrated in autoimmune conditions

Question 10

What test to do if ACTH Stim not avaliable?

Answer 10

9 am serum cortisol:
> 500 nmol/l makes Addison’s very unlikely
< 100 nmol/l is definitely abnormal
100-500 nmol/l should prompt a ACTH stimulation test to be performed

Question 11

Blood abnormalities in addisons?

Answer 11

hyperkalaemia
hyponatraemia
hypoglycaemia
metabolic acidosis

Question 12

Management of addisons disease?

Answer 12

Glucocorticoid and Mineralocorticoid replacement therapy

Glucocorticoid: hydrocortisone
Mineralocorticoid: Fludricortisone