Review Question - QID 104380

The history, exam and laboratory testing in this vignette support a diagnosis of idiopathic central precocious puberty. This condition is treated with GnRH agonists to suppress hypothalamic-pituitary axis.

Precocious puberty is defined as puberty that begins before age 8 in girls and before age 9 in boys. It is estimated that precocious puberty affects between 1 in 5000 and 1 in 10,000 children and a high female to male ratio. The causes of precocious puberty are broadly subdivided according to a functional classification based on gonadotrophin dependence and gonadotrophin non-dependence. Central precocious puberty is diagnosed by pubertal levels of LH that increase with GnRH stimulation, and is termed idiopathic when no obvious pathology is responsible for the elevated central hormones (e.g. tumor).

Blondell et al. discuss pubertal disorders. Normal puberty begins between 8-14 years of age in girls and between 9-14 years in boys. Puberty is staged by pubic hair distribution, along with breast size and contour in girls and testicular volume in boys. Some cases are "constitutional", but precocity is most often pathologic if it occurs in very young children, or if the sequence of normal pubertal milestones is disrupted.

Mul and Hughes discuss the treatment of central precocious puberty. The chief treatment modality is GnRH analogues, which function by desensitizing the signaling pathway to gonadotrophin production. The goals of treatment are to halt and perhaps reverse the secondary sex characteristics, prevent early onset of menses in girls, and stop the loss of height potential secondary to advanced skeletal maturation as a result of premature fusion of epiphyseal plates.

Illustration A is a diagram of the etiologies of precocious puberty.
Illustration B is a diagram of the stages of puberty development (Tanner stages).

Incorrect Answers:
Answer 1: Ketoconazole is a steroid synthesis inhibitor used most commonly in the treatment of PCOS.
Answer 3: Finasteride is a 5 alpha-reductase inhibitor used in the treatment of BPH and male-pattern baldness.
Answer 4: Octreotide is an somatostatin analogue used in the treatment of acromegaly, carcinoid, gastrinomas, glucagonomas, acute esophageal variceal bleeds.
Answer 5: Anastrozole is an aromatase inhibitor most commonly used in the treatment of breast cancer in post-menopausal women.