Addisons disease Flashcards
What is Addison’s disease?
Addison’s disease is the autoimmune destruction of the adrenal glands, leading to primary hypoadrenalism, which accounts for 80% of cases in the UK.
What hormones are reduced in Addison’s disease?
Cortisol and aldosterone are reduced in Addison’s disease.
What are common features of Addison’s disease?
Common features include lethargy, weakness, anorexia, nausea & vomiting, weight loss, and ‘salt-craving’.
What skin changes are associated with Addison’s disease?
Hyperpigmentation, especially in palmar creases, is associated with Addison’s disease.
What is the relationship between ACTH and hyperpigmentation?
ACTH is derived from proopiomelanocortin (POMC); its cleavage also produces melanocyte-stimulating hormones (MSH), which stimulate melanin production, leading to hyperpigmentation.
How does primary Addison’s disease differ from secondary adrenal insufficiency?
Primary Addison’s disease is associated with hyperpigmentation, whereas secondary adrenal insufficiency is not.
What are some additional features of Addison’s disease?
Additional features may include vitiligo, loss of pubic hair in women, hypotension, hypoglycaemia, hyponatraemia, and hyperkalaemia.
What are the symptoms of an Addisonian crisis?
Symptoms of an Addisonian crisis include collapse, shock, and pyrexia.
What are primary causes of hypoadrenalism?
Primary causes include tuberculosis, metastases (e.g. bronchial carcinoma), meningococcal septicaemia (Waterhouse-Friderichsen syndrome), HIV, and antiphospholipid syndrome.
What are secondary causes of hypoadrenalism?
Secondary causes include pituitary disorders such as tumours, irradiation, and infiltration.
What is a common treatment-related cause of hypoadrenalism?
Exogenous glucocorticoid therapy can lead to hypoadrenalism.
What is the definite investigation for suspected Addison’s disease?
The ACTH stimulation test (short Synacthen test).
What is measured during the ACTH stimulation test?
Plasma cortisol is measured before and 30 minutes after giving Synacthen 250ug IM.
What adrenal autoantibodies may be demonstrated in Addison’s disease?
Adrenal autoantibodies such as anti-21-hydroxylase.
What can be useful if an ACTH stimulation test is not readily available?
Sending a 9 am serum cortisol.
What does a serum cortisol level > 500 nmol/l indicate?
It makes Addison’s very unlikely.
What does a serum cortisol level < 100 nmol/l indicate?
It is definitely abnormal.
What should be done if serum cortisol is between 100-500 nmol/l?
An ACTH stimulation test should be performed.
What electrolyte abnormalities are associated with undiagnosed Addison’s disease?
Hyperkalaemia, hyponatraemia, hypoglycaemia, and metabolic acidosis.
What is the primary treatment for Addison’s disease?
Patients with Addison’s disease are usually given both glucocorticoid and mineralocorticoid replacement therapy.
What is the common glucocorticoid used in Addison’s disease management?
Hydrocortisone is commonly used, typically in 2 or 3 divided doses.
What is the usual daily dosage of hydrocortisone for Addison’s disease?
Patients typically require 20-30 mg per day, with the majority given in the first half of the day.
What mineralocorticoid is used in Addison’s disease management?
Fludrocortisone is used as part of the treatment.
What is an important aspect of patient education for Addison’s disease?
Emphasise the importance of not missing glucocorticoid doses.
What should patients consider for emergencies related to Addison’s disease?
Consider MedicAlert bracelets and steroid cards.
What should patients be provided with for an adrenal crisis?
Patients should be provided with hydrocortisone for injection with needles and syringes.
How should glucocorticoid doses be adjusted during an intercurrent illness?
The glucocorticoid dose should be doubled, while the fludrocortisone dose stays the same.
Where can guidelines for managing intercurrent illness in Addison’s disease be found?
The Addison’s Clinical Advisory Panel have produced guidelines detailing particular scenarios.
What are the causes of Addisonian crisis?
Sepsis or surgery causing an acute exacerbation of chronic insufficiency (Addison’s, Hypopituitarism), adrenal haemorrhage (e.g., Waterhouse-Friderichsen syndrome), and steroid withdrawal.
What is the management for Addisonian crisis?
Hydrocortisone 100 mg IM or IV, 1 litre normal saline infused over 30-60 mins or with dextrose if hypoglycaemic. Continue hydrocortisone 6 hourly until the patient is stable.
Is fludrocortisone required during Addisonian crisis management?
No, fludrocortisone is not required because high cortisol exerts weak mineralocorticoid action.
When can oral replacement begin after an Addisonian crisis?
Oral replacement may begin after 24 hours and be reduced to maintenance over 3-4 days.
