(17.10) Cushing’s Syndrome from unrecognized glucocorticoid use

Exogenous glucocorticoid use is the most common etiology for Cushing’s Syndrome. While this can be obvious from a review of a patient’s prescription history, at times, the source of glucocorticoid may not be evident. We present two cases of Cushing’s caused by supplements containing dexamethasone.

Case(s) Description :

Case 1.

66 yo M who had been admitted for a finger injury resulting in cellulitis and MSSA Bacteremia, who during his 1 month admission to the hospital had developed hypotension and hyponatremia for which he was evaluated for adrenal insufficiency. Biochemical evaluation included an early morning cortisol which was 2.1 mcg/dL. His 1 hour cortisol post 250 mcg ACTH was 4.6 mcg/dL. Following this he was started on glucocorticoid replacement therapy with hydrocortisone. During follow up outpatient evaluation, clinical exam was significant for moon facies, purpura in forearms. Upon further history taking, he reported history of Gout for which he had been applying a topical supplement twice daily named Artri Ajo King, which he obtained at the Hmong Marketplace. This supplement has been previously reported to contain dexamethasone.

Case 2.

66 yo M initially seen by PCP for erectile dysfunction, initial evaluation found him to have hypogonadotropic hypogonadism, which led to further pituitary evaluation which was remarkable for biochemical evidence of secondary adrenal insufficiency with a serum cortisol of 0.4 mcg/dL an ACTH of 3.5 pg/mL. During initial evaluation with Endocrinology, his exam was significant for facial plethora, arm and abdominal wide and purple striae and proximal muscle weakness. Further history was relevant for history of Gout for which he had been taking an unlabeled “natural supplement” which he obtained from Thailand. Patient was asked to take his supplement, after which a serum synthetic steroid screen was obtained which showed presence of Dexamethasone (0.55 mcg/dL, cutoff of 0.1).

Discussion :

Given that Cushing’s Syndrome’s most common etiology is exogenous steroid use, it is critical that initial interview is focused on ruling out any potential sources of exogenous steroids, both prescribed and non-prescribed, prior to initiating further diagnostic testing. In the first case, the supplement was previously identified to contain unlabeled dexamethasone. In the second case, the supplement was unlabeled, but we were able to identify the presence of dexamethasone by doing a synthetic steroid screen in serum.

 In cases presenting with clinical findings of Cushing’s but with biochemical evidence of cortisol deficiency, clinicians should suspect use of synthetic steroids. When not evident by history, a serum synthetic steroid screen can aid in confirming the diagnosis.