Internal Medicine

P1: RLJ/OZN P2: KUF

0521779407-D-01 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:41

470 Dermatofibroma Diabetes Insipidus

follow-up

■After removal, no follow-up is usually needed.

complications and prognosis

■Dermatofibroma persists if not removed.

Diabetes Insipidus...................................

ANDREW R. HOFFMAN, MD

history & physical

History

■Abrupt onset of severe thirst, esp for cold liquids

■Polyuria, polydipsia (may be >1.0 L/h)

■Nocturia

■History of pituitary tumor, surgery, apoplexy, or irradiation

■Head trauma

■Craniopharyngioma

■Dysgerminoma

■Metastatic cancer, esp. breast and lung

■Histiocytosis X, sarcoidosis, TB

■3rd trimester of pregnancy

Signs & Symptoms

■Dehydration

■Hypernatremia, hyperosmolality

■Altered mental status, coma

■Orthostatic hypotension

tests

Laboratory

■Basic studies:

➣Serum sodium, serum osmolality, calcium, glucose

➣Urine osmolality, urine analysis with specific gravity (<1.005 in

DI)

■Ancillary tests:

➣Serum ADH (aka AVP)

➣Lithium level

■Dehydration testing: withhold fluids until serum osmolality rises;

treat with parenteral DDAVP to distinguish central (pituitary) DI from

nephrogenic DI and primary polydipsia