Adrenal insufficiency.

Adrenal insufficiency is a life-threatening condition that occurs secondary to impaired secretion of adrenal glucocorticoid and mineralocorticoid hormones. This condition can be caused by primary destruction or dysfunction of the adrenal glands or impairment of the hypothalamic-pituitary-adrenal axis. In children, the most common causes of primary adrenal insufficiency are impaired adrenal steroidogenesis (congenital adrenal hyperplasia) and adrenal destruction or dysfunction (autoimmune polyendocrine syndrome and adrenoleukodystrophy), whereas exogenous corticosteroid therapy withdrawal or poor adherence to scheduled corticosteroid dosing with long-standing treatment constitute the most common cause of acquired adrenal insufficiency. Although there are classic clinical signs (eg, fatigue, orthostatic hypotension, hyperpigmentation, hyponatremia, hyperkalemia, and hypoglycemia) of adrenal insufficiency, its early clinical presentation is most commonly vague and undefined, requiring a high index of suspicion. The relevance of early identification of adrenal insufficiency is to avoid the potential lethal outcome secondary to severe cardiovascular and hemodynamic insufficiency. The clinician must be aware of the need for increased corticosteroid dose supplementation during stress periods.