Addison's disease

Addison's disease, or primary adrenocortical failure, is rare, most commonly caused in the UK by autoimmune destruction of the adrenal glands. The insidious onset of symptoms over many months means there is often a delay in diagnosis and patients can first present in adrenal crisis, which is life-threatening if not appropriately treated. The diagnosis is made by finding a low serum cortisol at 09:00 hours in the presence of an elevated adrenocorticotropic hormone (ACTH) concentration, or by a suboptimal cortisol response to exogenous ACTH on provocation testing. Replacement with hydrocortisone and fludrocortisone should approximate physiological concentrations as closely as possible. Patients and families should have a good understanding of the condition and how to adjust the corticosteroid dosing in times of illness.