Case 2 - Explanation
This is a classic presentation of secondary adrenal insufficiency: someone on a prolonged course, or multiple courses, of corticosteroids and then stops taking them.
Corticosteroids block the release of corticotropin-releasing hormone (CRH) and ACTH via negative feedback. This means that the pituitary release of ACTH is diminished. In the absense of ACTH drive adrenal function is down regulated and it is recommended that the steroid is tapered slowly over time to allow for recovery of the endogenous pituitary - adrenal axis.
At times of increased stress, such as intercurrent illness, this becomes more obvious and the patient can be haemodynamically compromised.
