Failure to suppress adrenal function in congenital adrenal hyperplasia (21-hydroxylase deficiency). Three case reports.

Three patients, aged 14, 16, and 32 years respectively, with congenital adrenal hyperplasia (21-hydroxylase deficiency) are described. Excessive adrenal activity and ACTH secretion could not be suppressed with doses of corticosteroids sufficient to cause iatrogenic Cushing's syndrome, even though part of the steroid dosage was administered in the late evening. The resistance to feed-back suppression was of the same order as that seen in Cushing's syndrome. Adrenalectomy was performed in the 16-year-old girl, and was followed by a menarche. Adrenalectomy was considered inadvisable in the other two patients.