Cushing’s Syndrome

Hospital Physician April 2008 25 C ushing’s syndrome was first described by Harvey Cushing in 1910 in a woman with central obesity, abdominal striae, hirsutism, amenorrhea, hypertension, proximal muscle weakness, thinning hair, and purpura.1,2 Cushing’s syndrome is now known to be associated with hypercortisolism, either endogenous or exogenous in origin. Endogenous causes of Cushing’s syndrome are classified as either dependent or independent of adrenocorticotropin hormone (ACTH), determined by assessing serum ACTH level in relation to serum cortisol level. Exogenous hypercortisolism is most often caused by excessive use of pharmacologic glucocorticoids. Cushing’s syndrome is rare, with a prevalence of 2 to 5 cases per million.3,4 Although several signs and symptoms are suggestive of Cushing’s syndrome (eg, weight gain, central obesity, moon facies, abdominal striae, buffalo hump), no single physical finding is pathognomonic. The diagnosis is confirmed through biochemical testing, and treatment is dependent on the cause of hypercortisolism. This article describes some of the more common manifestations of Cushing’s syndrome and discusses the differential diagnoses and work-up of suspected Cushing’s syndrome.