Internal Medicine

0521779407-C04 CUNY1086/Karliner 0 521 77940 7 June 14, 2007 20:37

436 Cushing’s Syndrome

■Muscle weakness, atrophy

■History of exogenous glucocorticoid administration

■Alcoholism

■Family history of Cushing syndrome (CS)

■Cigarette smoking, weight loss, bone/abdominal pain, flushing

■Visual field abnormalities, other pituitary disease, galactorrhea

Signs & Symptoms

■Neuropsychiatric: Depression, insomnia, mania, psychosis

■Muscle weakness, easy bruising, stretch marks (striae)

■Women: hirsutism, virilism, thinning of scalp hair, acne, amenor-

rhea/menstrual irregularity

■Men: decreased libido, gynecomastia, impotence

■Hyperpigmentation (with ACTH excess)

■Edema, polyuria, nocturia

■Hypertension, acne, hirsutism, easy bruising, hyperpigmentation

■Central obesity, striae (1.0 cm, violaceous), fragile skin, nonhealing

ulcerations

■Supraclavicular fat pads, dorsal fat pad, moon facies

■Muscle atrophy, proximal muscle weakness

■Hypokalemia, alkalosis

tests

■Screening:

➣1.0 mg overnight dexamethasone suppression test (1.0 mg dex-

amethasone at midnight, check 8 AM cortisol): normal <2 mcg/

dL; limited specificity; false-positive with stress, anticonvulsant

therapy, oral contraceptives, obesity; concomitant DEX level may

be useful

➣24-h urine free cortisol (and creatinine to assure adequate 24-hr

urine collection)

■Confirmatory:

➣Evening (10–12 PM) to morning (6–8 AM) serum/salivary cortisol

ratios

➣Serial evaluation of (midnight) salivary cortisol for cycli-

cal/periodic CS

➣2-d medium dose (2 mg) dexamethasone suppression test

■Tests to establish the cause of CS:

➣8 AM plasma ACTH level:

Low in ACTH-independent