Overview
Puberty is a complex transitional phase in children generally comprising of growth acceleration and development of secondary sexual characteristics. It is a period of physical and psychosocial development. Several genetic, environmental and nutritional factors play an important role in the onset and progression of puberty.[1]
Physiology of puberty
Puberty results from the activation and maturation of the hypothalamic-pituitary-gonadal (HPG) axis. At birth, there is a brief activation of the HPG axis that results in the increased production of steroidal hormones. This activation may result in breast development in females and pubic hair in males. This phenomenon is known as the “mini-puberty of the infancy” usually regresses over the first two years of life. Although it is considered to be benign, there is very little information on its etiology as well as clinical significance.
The HPG axis then becomes dormant until its subsequent activation in adolescence. The pulsatile release of gonadotropin-releasing hormone (GnRH) from the hypothalamus stimulates the secretion of follicle stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary gland. FSH and LH initiate spermatogenesis and the release of testosterone in males, and oogenesis and the release of estradiol in the females, respectively. Activation of the gonads is known as gonadarche.
It is important for a clinician to be familiar with the terminology of pubertal progression. Thelarche is the development of breasts, which is a response to estrogen. Pubarche is the development of pubic hair, which is a response to androgens. Adrenarche is the onset of adrenal androgen production, which contributes to pubarche.
Definition
The traditional definition of precocious puberty is the development of secondary sexual characteristics before 8 years of age in girls and 9 years in boys.
