Puberty and its disorders in girls.

Current concepts of normal and pathologic puberty have been reviewed. The key event in normal puberty is the commencement of pulsatile secretion of GnRH during sleep, which leads to augmentation of LH levels with the onset of sleep. Schemata are presented for the initial evaluation of patients with primary amenorrhea and secondary amenorrhea based on whether they are hypoestrogenic or estrogenized. Menstrual abnormalities are also discussed from a diagnosis-based perspective. The role of the bone age in differential diagnosis of pubertal disorders is emphasized. The variable presentations of Turner syndrome, hyperprolactinemia, and PCOS are reviewed. Current understanding of the role of undernutrition and stress in anorexia nervosa, psychogenic amenorrhea, and athletic amenorrhea is presented, and management guidelines are reviewed. The evidence that premature pubarche is usually due to premature adrenarche is discussed. The concept that premature thelarche lies on a spectrum between normal and early puberty is discussed. The reader is also reminded that many girls with idiopathic true sexual precocity do not require treatment to preserve height potential.