- Failure of adrenals to produce steroids due to –
- Atrophy/destruction of adrenal gland = primary adrenal failure
- Rarer causes: infection (HIV, fungi), invasion with cancer cells (lymphoma, breast, lung), haemorrhage (due to anti-coagulants, Waterhouse-Friedrichsen syndrome, meningococcal-induced DIC), infiltration (amyloid, sarcoid, haemochromatosis), congenital adrenal hyperplasia, drugs (ketoconazole).
- In primary adrenal failure, cortisol deficiency increases ACTH release, causing release of MSH – causing hyperpigmentation in buccal mucosa and on palms and soles. This does not occur in secondary adrenal failure as there is decreased ACTH!
- Inadequate adrenocorticotrophin hormone (ACTH) production = secondary adrenal failure! The most common cause linked to sudden steroid withdrawel.
- o Secondary causes: chronic steroid therapy supresses ACTH levels (v common), producing adrenal cortex atrophy – physical stress or over-quick steroid withdrawel = acute adrenal failure, pituitary failure.