Poster Presentation ESA-SRB Conference 2015

The distinction between Cushing’s Syndrome (CS) and Pseudo-Cushing’s Syndrome (PCS) can be difficult: more difficult in acutely unwell patients. PCS occurs in patients with systemic conditions that activate the hypothalamic-pituitary-adrenal (HPA) axis; the principle mediator of a stress response.¹ This case illustrates the difficulties in diagnosing CS during critical illness; and the effects of critical illness on the HPA axis.

A 36 year old male was admitted with subacute combined degeneration of the cord secondary to B12 deficiency, following progressive, debilitating limb weakness, parasthesia and ataxia. His admission was complicated by intestinal pseudo-obstruction.

He appeared overtly hypercortisolemic, with moon facies, buffalo hump, supraclavicular fat pads, marked purplish-red striae (>1cm width) and had proximal myopathy (Fig. 1a & 1b). He denied any exogenous steroid use but history was significant for alcohol dependence, averaging 28 standard drinks (SD) daily.

Screening tests for CS revealed: elevated midnight salivary cortisol 32.9nmol/L (normal <10nmol/L), failure to suppress cortisol levels following an overnight low-dose 1mg dexamethasone suppression test (DST) (cortisol 210nmol/L), and detectable ACTH (21ng/L). However, a 24-hour urinary free cortisol was normal. The remainder of his hormone profile appeared to show deficiencies of gonadotrophins (LH 0.7 IU/L, FSH 0.4 IU/L, testosterone 1.7nmol/L) and the somatotroph axis (IGF-1 7nmol/L (15-40), GH 0.7ug/L). Thyroid hormone axis was intact.

Following near-recovery ten days later, repeat low-dose followed by high-dose DST now showed appropriate cortisol suppression. His gonadotroph and somatotroph axes also normalized. Post-hospital discharge, his alcohol intake has reduced significantly (3 SD/ week); with substantial loss of his previous phenotypic Cushingoid features (Fig. 2).

We report an uncommon cause of PCS secondary to longstanding alcoholism and critical illness. Rapid restoration of normal pituitary axis function was seen with resolution of illness and alcohol abstinence. We highlight some of the difficulties in the diagnosis of CS during critical illness.