last authored: Oct 2009, David LaPierre
Puberty begins with the appearance of secondary sexual characterstics and ends with the end of the growth spurt.
Puberty occurs following maturation of the HPG axis. Increased pulsatile release of GnRH leads to release of LH and FSH, causing gonadal maturation and release of sex steroids. Adrenal production of androgens also occurs.
Puberty begins with the appearance of secondary sexual characterstics and ends with the end of the growth spurt.
Normal male puberty occus between ages 9-14, 2 years after females.
Testicular volume enlargement is the first sign of puberty.
tanner 1:
tanner 2: testicular increase from 2- 4ml, sparse pubic hair
tanner 3: 8-10 ml - acceleration of puberty
tanner 4: penis length and breadth enlargement, coarse pubic hair, growth spurt
tanner 5: adult size and shape of penis, pubic hair to medial thigh
Gonadarche, or enlargement of the testes, is usually the first sign of pubery and often occurs at the same time as pubic hair growth. Spermatogenesis usually begins months after gonadarche.
The penis begins to grow about a year after gonadarche, is androgen-dependent, and continues after puberty.
Adrenarche leads to axillary and facial hair growth, body odour, and acne. The growth spurt in Tanner stage 4.
Delayed puberty:
Normal female puberty occurs between 8-13, though can begin as early as 6 in black girls.
Thelarche, onset of breast development, is the first stage. Asymmetry is common.
Adrenarche is the increase in adrenal androgens occurring before changes in the HPG axis, and is reponsible for growth of pubic and axillary hair, body odour, and acne.
Menarche occurs at a mean of 13 years, perhaps 2 years after breast development. It indicates the growth spurt is nearing completion.
Menstruation is often at first irregular, and it takes ~18 months for the first 12 periods.
tanner 2: small breast bud; sparse labial hair
tanner 3: adult appearance, but smaller, hair over pubis
tanner 4: areola and nipple form secondary mound, coarse pubic hair
tanner 5: adult appearance, pubic hair extends to medial thigh
at puberty, the pituitary begins secreting pulses of gonadotrophins LH and FSH at night, with pulses occuring during the day in adults as well. Pulses are the same in both females and males, and play a key role in sexual differentiation.
anorexia inhibits these pulses and therefore puberty
breast development (thelarche) usually occurs first, but not always; menarche occurs, on average, two years after thelarche
Can occur in boys and girls before age six, leading to pubic and axillary hair, body odour, and mild acne. Caused by adrenal production of DHEAS. Investigate for other signs of puberty (thelarche in girls or testicular enlargement in boys). Exclude androgen-secreting tumours.
Common; seen in 50% of male adolescents.
Transient, can be asymptomatic
Investigate if nipple discharge or fixed mass.
Distingusih breast tissue from fat
Delayed puberty is common in males but rare in females.
Early puberty is common in females but uncommon in males.
Do brain imaging on any girl under 6 years of age, or any boy presenting with precocious puberty.
Do GnRH stimulation testing to determine if is gonadotropin dependent (LH/FSH will increase) or independent (no change).
Examine testosterone, 17-hydroxyprogesterone - elevated in CAH
Potential causes: