Puberty Flashcards
What is adrenarche and when does it occur?
- Activation of zona reticularis - increased adrenal androgen production.
- Before puberty (6-8 years)
What is thelarche and when does it occur?
- Breast development
2. 2-3 years before menarche
What is gonadarche and when does it occur?
- Increasing testicular volume
2. 12 years of age
What is pubarche and when does it occur?
- Appearance of pubic hair.
2. 6 months after thelarche (girls), 1-2 years after initial testicular enlargement (boys).
What is menarche and when does it occur?
- Onset of menstruation.
2. Just under 13 years
What is spermarche and when does it occur?
- Onset of sperm production.
2. 13-14 years.
What hormonal change causes enlargement of testes?
Pulses of pituitary gonadotrophins
What hormonal changes causes breast enlargement in girls and penis enlargement in boys?
Gonadal sex steroid production
What hormonal change causes pubic hair to form?
Adrenal androgen production
What are the Tanner stages in girls?
- Pre-pubertal
- Areola enlarges, breast buds, sparse pigmented hair along labia.
- Breast grows beyond areola, nipple elevates, hair becomes darker/coarser.
- Areola and papilla project above breast, secondary mound, adult type hair in small area.
- Adult breast contour, projection of papilla only, adult hair type and distribution.
What are the Tanner stages in boys?
- Pre-pubertal, testicular volume <2.5ml
- Sparse hair around penis base, testes and scrotum enlarge, scrotal skin thins and reddens.
- Darker/coarse/curly hair spreads laterally, further testes and penis growth.
- Adult type hair in small area, further penis growth, scrotal skin darkens.
- Adult hair type and distribution, and genitalia.
What is the definition of puberty?
Period of sexual maturation during which a child’s body undergoes physical changes to become an adult body with functional reproductive organs.
What is the normal age for puberty in boys and girls?
9-14 for boys, 8-13 for girls.
Which genders are precocious and delayed puberty more common in?
- Precocious - girls
2. Delayed - boys
What is the definition of delayed puberty?
Lack of any breast development by 13 in girls and testicular volume <4ml by 14 years in boys.
What are the central causes of delayed puberty?
Pituitary/hypothalamus:
- Constitutional delay
- Chronic disease
- Malnutrition/anorexia nervosa
- Pituitary tumours/radiotherapy
- Congenital GnRH deficiency
What are the peripheral causes of delayed puberty?
Gonads:
- Turner’s syndrome
- Klinefelter’s syndrome
- Bilateral testicular damage (torsion/mumps)
What is this a presentation of?
Boy, tall stature, mild learning difficulties, lack of body and facial hair, long arms and legs, gynaecomastia, female body fat distribution, small firm tester, subfertile.
Klinefelter’s syndrome
What is the genotype of Klinefelter’s syndrome and what are the hormone levels (LH/FSH/testosterone)?
- XXY
2. High LH/FSH, low testosterone
What is this a presentation of?
Boy, delayed puberty, anosmia, hypogonadism.
Kallmann’s syndrome
What is the pathophysiology of Kallmann’s syndrome, what is the inheritance pattern, and what are the hormone levels (LH/FSH/sex hormones)?
- Failure of GnRH neurones to migrate to the hypothalamus.
- X-linked recessive
- Low FSH/LH, low sex hormones
How is delayed puberty investigated?
- Formal puberty staging, growth, body composition
- Dysmorphic features - karyotype
- Bone age radiographs
- Pelvic USS, brain MRI
- LH, FSH, E2, testosterone
- TFTs, inflammatory markers
What are the differences in hormone levels between primary and secondary hypoG-hypoG?
- Primary hypoG-hypoG - low sex hormones, normal/high FSH and LH
- Secondary hypoG-hypoG - every thing is low
What is the management for delayed puberty?
- All with constitutional delay enter puberty spontaneously.
- If delay is causing distress, can be induced by testosterone or oestrogen.
What is precocious puberty?
Signs of puberty before 8 in girls and 9 in boys.
What are the central causes of precocious puberty?
Pituitary/hypothalamus:
- Familial early puberty
- Hypothyroidism
- Obesity
- Idiopathic
- Brain tumour
What are the peripheral causes of precocious puberty?
Gonads/adrenal:
- Ovarian, testicular, or adrenal tumours
- Congenital adrenal hyperplasia
- Exposure to exogenous sex steroid hormones
What are the clinical features of central precocious puberty?
Concordant and progresses normally
What are the clinical features of peripheral precocious puberty?
- Girls - clitoromegaly and hirsutism
2. Boys - increased penis length without testicular enlargement
How is precocious puberty investigated?
- Bone age radiography
- Boys - high early morning testosterone
- Girls - high oestrogen
- 17-OH progesterone on short synacthen for CAH
- GnRH stimulation test - LH and FSH rises in central, not in peripheral
- Left and right spermatic vein sampling for Leydig tumours
- Adrenal and pelvic USS
- MRI brain if suspecting tumour
What is the management for precocious puberty?
- Some choose to progress through puberty
- Can halt puberty using GnRH agonists (SC/nasal)
- Treat peripheral causes by treating the cause, GnRH won’t work.
