Addison's disease

Autoimmune destruction of the adrenal glands is the most common cause of primary hypoadrenalism in the UK, accounting for 80% of cases. This is termed Addison's disease and results in reduced cortisol and aldosterone being produced.

Features

lethargy, weakness, anorexia, nausea & vomiting, weight loss, 'salt-craving'
hyperpigmentation (especially palmar creases)
- ACTH is derived from a larger precursor molecule called proopiomelanocortin (POMC). When POMC is cleaved to produce ACTH, other melanocyte-stimulating hormones (MSH) are also produced. These MSHs have the effect of stimulating melanocytes in the skin to produce more melanin, the pigment responsible for skin colour
- primary Addison's is associated with hyperpigmentation whereas secondary adrenal insufficiency is not
vitiligo
loss of pubic hair in women
hypotension
hypoglycaemia
hyponatraemia and hyperkalaemia may be seen
crisis: collapse, shock, pyrexia

Other causes of hypoadrenalism

Primary causes

tuberculosis
metastases (e.g. bronchial carcinoma)
meningococcal septicaemia (Waterhouse-Friderichsen syndrome)
HIV
antiphospholipid syndrome

Secondary causes

pituitary disorders (e.g. tumours, irradiation, infiltration)

Exogenous glucocorticoid therapy

+PassMedicine Notes

Features

lethargy, weakness, anorexia, nausea & vomiting, weight loss, 'salt-craving'
hyperpigmentation (especially palmar creases)

ACTH is derived from a larger precursor molecule called proopiomelanocortin (POMC). When POMC is cleaved to produce ACTH, other melanocyte-stimulating hormones (MSH) are also produced. These MSHs have the effect of stimulating melanocytes in the skin to produce more melanin, the pigment responsible for skin colour
primary Addison's is associated with hyperpigmentation whereas secondary adrenal insufficiency is not