Puberty Flashcards
Adenarche v. Gonadarche
- Adenarche - maturation of adrenal cortex –> adrenal androgen synthesis (precedes gonadarche by 2-3 yrs and does not stimulate it)
- Change in responsiveness to ACTH –> DHEAS (starts at about 6 yo)
- Gonadarche - growth and maturation of gonads which leads to secretion of sex hormones
- Girls - estrogen –> breast development
- Boys - testosterone –> testicular enlargement
Thelarche
Menarche
Spermarche
Pubarche
- Thelarche - appearance of breast tissue (usually first)
- Menarche - onset of menses (usually 2.6 yrs after puberty starts)
- Spermarche - first ejaculation or presence of sperm in urine
- Pubarche - presence of pubic hair
What is the mean age of onset of female puberty? In what order does it typically progress?
- Mean Onset = 10.5 yo
- Order
- 1- Inc linear growth (9 yo)
- 2- Thelarche
- 3- Pubarche
- 4- Peak height velocity
- 5- Menarche
Tanner Stages of Breast Development
- I - no palpable breast tissue
- II - breast bud so elevated at papilla and enlargement of areolar diameter
- III - enlargement of breast but no separation of areolar contour from breast
- IV - areola and papilla project above breast
- V - recession of areola to match contour of breast
Tanner Stages of Hair Development (both sexes)
- I - no pubic hair
- II - sparse, straight hair along lalteral vulva or base of penis
- III - dark, coarser, curlier, extends over mid-pubis
- IV - adult like appearance but does not extend to thighs
- V - adult like appearance from thigh to thigh
Tanner Stages of Male Development
- I - prepubertal
- II - enlargement of scrotum and testes, scrotal skin reddens and changes texture
- III - enlargement of penis, further growth of testes; coarse
- IV - penis grows in breadth and glans forms; larger testes and scrotum; darker scrotal skin
- V - adult genitalia
What is the mean age of onset of male puberty? In what order does it typically progress?
- Mean onset = 11.5 yo
- Order
- 1- inc testicular volume (meas w/ Prader orchidometer)
- 2- pubic hair
- 3- height inc
- 4- sperm in urine
How is precocious puberty defined?
- Defined by - >2.5 SDs earlier than average
- < 8 yo in girls
- < 9 yo in boys
MORE COMMON IN GIRLS
Incomplete Precocious Puberty
- Isolated premature breast development in girls (no other secondary sex characteristics or progression)
- May be related to maternal estrogen if seen in infants
- OR premature adrenarche (isolated activation of HPA axis w/o gonadarche - body odor or pubic hair - DHEAS > 40)
- May be related to obesity and DM
- Monitor - 20% will progress
Central or True Precocious Puberty
- Gonadotropin-Dep
- Early HPG axis maturation
- Presentation
- Accelerated linear growth and bone age
- Pubertal levels of FSH/LH/ sex steroids
- Gender appropriate sex characteristics - Causes - 90% idiopathic; CNS lesions (hamartomas, other hypothalamus or pituitary lesions, trauma or CNS infections, mutations)
- Tx - continuous GnRH agonist to down-regulate pulses (Leuprolide injections or implant)
Peripheral or Pseudo Precocious Puberty
- Gonadotropin - Indep
- NOT early HPG axis but extra sex steroids (from gonads, exogenous source, ectopic gonadotropin secreting tumor)
- Presentation
- Poss gender-inappropriate sex characteristics
- Suppression of FSH/LH - Causes include … ovarian cysts that secrete estrogen, gonadal tumors, adrenal tumor or CAH, exogenous steroid use, severe primary hypothyroidism, McCune-Albright Syndrome
- Tx - aromatase inhibitors to block estrogen production from androgens; treat underlying cause
McCune-Albright Syndrome
- mutation causing cont stimulation and activation of FSH receptor
TRIAD
- precocious puberty
- cafe-au-lait spots
- fibrous bone lesions (“limp”)
How can severe hypothyroidism lead to precocious puberty?
- Excess TSH to comp –> TSH acts on FSH receptor
- Only case where you see DELAYED bone growth (underlying hypothyroid)
How is delayed puberty defined?
- Absence or incomplete development of secondary sex characteristics by age when 95% of kids have initiated sexual maturation
- Boys - 14 yo
- Girls - 12-13 yo
Causes of Delayed Puberty (labs for ea)
- Primary - gonad problem (Turners, chemo, radiation, gonadal dysgenesis, premature ovarian failure) - high LH/FSH
- Secondary - hypothalamus, pituitary, thyroid
- Permanent or functional (systemic illness, hypothyroid, excessive exercise) - low LH/FSH