Secondary adrenal insufficiency can result from insufficient stimulation of the adrenal glands due to inadequate secretion or synthesis of adrenocorticotropic hormone (ACTH). This can be caused by hypopituitarism, central nervous system injury (tumors, radiation, and surgery) or long-term glucocorticoid therapy. Glucocorticoids were introduced in the 1950s, and have been used for their anti-inflammatory and other pharmacological effects, and also as replacement therapy for adrenal insufficiency. However, chronic glucocorticoid use may lead to suppression of the hypothalamic pituitary adrenal axis through negative feedback. This may lead to secondary adrenal insufficiency. Typically, the hypothalamic pituitary adrenal axis recovers after cessation of glucocorticoids, but the timing of recovery can be variable and can take anywhere from 6-12 months. Understanding the effect of exogenous glucocorticoids on the hypothalamic pituitary adrenal axis, recovery of the axis, and tests used to assess the recovery, are crucial to avoid prescribing unnecessary steroid replacement or missing a critical diagnosis with detrimental consequences.
Keywords: Adrenal insufficiency; adrenocorticotropic hormone (ACTH); glucocorticoid use; stimulation test.