True precocious puberty complicating congenital adrenal hyperplasia: treatment with a luteinizing hormone-releasing hormone analog.

Congenital adrenal hyperplasia (CAH) is a recognized cause of precocious pseudopuberty. Some children with CAH also develop true precocious puberty with early maturation of the hypothalamic-pituitary-gonadal axis. We have seen four such children (three boys and one girl) who had the diagnosis of CAH made between the ages of 3 and 6 yr. These patients were treated with standard doses of hydrocortisone and fludrocortisone. A diagnosis of true precocious puberty was made because of testicular enlargement in the boys, breast development in the girl, progressive pubic hair development, rapid growth, and rapid bone age maturation. Plasma steroid levels were elevated for age, and gonadotropin levels were within the normal pubertal range, both basally and in response to LHRH stimulation. We treated these children with daily sc injections of a LHRH analog (LHRHa) for 6-18 months in addition to the standard hydrocortisone and fludrocortisone therapy for CAH. LHRHa significantly decreased basal plasma LH and FSH, peak LH and FSH responses to native LHRH, and testosterone levels. Testis size decreased in the males, and breast development regressed in the female. LHRHa therapy led to significant decreases in linear growth rate, ulnar growth rate, and rate of bone age advancement. These results suggest that LHRHa is an effective adjunct to hydrocortisone and fludrocortisone in the treatment of true precocious puberty complicating CAH.