Adrenal Disorders
Adrenal steroidogenesis
The adrenal cortex makes mineralocorticoids, glucocorticoids, and androgens. Congenital adrenal hyperplasia (CAH) is most often 21-hydroxylase deficiency, causing cortisol and aldosterone deficiency with androgen excess. Females present with ambiguous genitalia; males may present only with salt-wasting crisis at 1–3 weeks: hyponatremia, hyperkalemia, hypoglycemia, acidosis, and shock. 11β-hydroxylase deficiency causes hypertension with low renin and virilization. 3β-hydroxysteroid dehydrogenase deficiency and StAR deficiency are rarer. Acquired adrenal insufficiency causes include Addison disease and autoimmune polyglandular syndromes.
Testing and traps
Measure 17-hydroxyprogesterone, electrolytes, renin, and glucose; confirm with cosyntropin stimulation when stable. A random cortisol is not sufficient. 17-hydroxyprogesterone can be elevated by stress or prematurity, so interpret it with the clinical picture. In central adrenal insufficiency, aldosterone is preserved, so potassium is normal. Do not miss adrenal crisis during illness; stress-dose hydrocortisone is required. In CAH, fludrocortisone and sodium supplementation are needed in infancy, and glucocorticoid doses must be adjusted for growth.
Worked example
A 10-day-old boy has vomiting, weight loss, sodium 126, potassium 6.8, and glucose 45. Check 17-hydroxyprogesterone and start hydrocortisone and saline; do not wait for the result if he is shocked. After stabilization, add fludrocortisone and teach stress dosing.