Available @ StudentConsult.com immediately after birth. Vomiting, dehydration, and acidosis soon follow, as does hypotensive shock from glucocorticoid deficiency. Death may occur if the disorder remains undiag- nosed and untreated. In females the ambiguity of the external genitalia is an obvious clue that salt-losing congenital adrenal hyperplasia (CAH) or simple virilizing CAH must be ruled The clinical manifestations of inadequate adrenal function out. Because these forms cannot be distinguished clinically, all result from inadequate secretion or action of glucocorti-presentations of ambiguous genitalia should involve evaluacoids, mineralocorticoids, or both (Table 178-1). In the case tion for mineralocorticoid deficiency. In males the most com-of enzyme defects that affect the gonad and the adrenal gland, mon form of CAH, 21-hydroxylase deficiency, does not cause overproduction or underproduction of potent androgens can abnormal genitalia. There may be hyperpigmentation of the occur, depending on the site of enzyme blockade (see Fig. 178-scrotal skin, but this is a subtle sign. In all infants, the diagnosis 1). Progressive prenatal virilization of the external genitalia may of adrenal insufficiency may be overlooked or confused with occur in females; incomplete virilization may occur in males. pyloric stenosis. In pyloric stenosis, in contrast to salt-losing Ambiguity of the external genitalia is a common manifestation CAH, vomiting of stomach contents results in hypochloremia, of disordered fetal adrenal enzyme function. Precise diagnosis serum potassium is normal or low, and alkalosis is present. is essential for the prescription of appropriate therapy, long-This distinction may be lifesaving in preventing unnecessary term outlook, and genetic counseling. In patients with enzyme investigations or inappropriate therapy. defects, an elevation in the precursor steroid is present proxi-Not all forms of adrenal hyperplasia present at birth; the mal to the enzyme block and is metabolized through remain-spectrum of disorder ranges from severe (classic) to mild ing normal alternate enzyme pathways, whereas a deficiency of (late-onset) or nonclassic. Milder forms may manifest in steroids is present subsequent to the block. childhood, adolescence, or even young adulthood (not as
Cortisol deficiency Hypoglycemia Inability to withstand stress Vasomotor collapse Hyperpigmentation (in primary adrenal insufficiency with excess of adrenocorticotropic hormone) Apneic spells Muscle weakness, fatigue
Aldosterone deficiency Hyponatremia Hyperkalemia Vomiting Urinary sodium wasting Salt craving Acidosis Failure to thrive Volume depletion Hypotension Dehydration Shock Diarrhea Muscle weakness glucocorticoid or mineralocorticoid deficiencies, but as androgen excess).
In patients with congenital adrenal hypoplasia or adrenal hemorrhage, the secretion of all adrenal steroids is low. In contrast CAH leads to a diagnostic steroid pattern in blood and urine (see Fig. 178-1). Deficiency of 21-hydroxylase is the most common form (95%) and serves as a paradigm for these disorders.
Available @ StudentConsult.com
Hypertension Precocious Puberty in the Male Precocious Puberty in the Female Ambiguous Genitalia Hirsutism