Disorders of puberty Flashcards
What is puberty
process of acquisition of secondary sexual characteristics and attainment of reproductive function
What are some secondary sexual characteristics
development of genitalia
pubic and axillary hair in boys and girls
development of breasts
increase in testicular volume
When does normal puberty occur
between the ages of 8 and 13 in girls
9-14 in boys
Usually lasts 3-4 years
What is the first step in initiation of puberty
activation of hypothalamic GnRH pulse generator and the pulsatile secretion of GnRH
What does the release of GnRH result in
an increase in plasma concentrations of LH, FSH and sex steroids (testosterone or estradiol)
What is the initial change in gonadotrophin secretion during the early stages of puberty
nocturnal increase in serum LH during sleep
What happens to LH levels later in puberty
Daytime LH levels also increase, gradually changing to the adult pattern
What is the function of leptin
it is a hormone produced largely in adipocytes and may act as a signal of the availability of the metabolic reserve necessary for pubertal development
What are the 5 Tanner stages in boys
1: prepubertal
2: scrotum and testes enlarge and scrotum skin reddens and changes in texture
3. Penis enlarges and the testes grow further
4: size of penis increases with a growth in breadth and development of the glans
5: adult genitalia
What are the 5 Tanner stages in girls
1: prepubertal
2: breast bud stage with elevation of breast and papilla, enlargement of areola
3. further enlargement of the breast and areola, no separation of their contour
4: Areola and papilla form a secondary mound above the level of the breast
5: Mature stage with projection of papilla only related to recession of the areola
What is thelarche
The first sign of puberty - the onset of breast development
What is pubarche
The development of pubic hair
When does menarche occur
2-3 years after the onset of puberty
When does the peak growth velocity (growth spurt) occur
Within the first year after the onset of puberty in girls
Usually 2 years after the onset of puberty
What is the first sign of puberty in boys
an increase in testicular volume
At what Tanner stage does spermatogenesis begin
stage 3
What is delayed puberty
the absence or incomplete development of secondary sexual characteristics by an age at which 95% of children of that sex and culture have initiated sexual maturation
What is constitutional delay of growth and puberty characterised by
a delayed onset of puberty, pubertal growth spurt and skeletal maturation
How is the predicted height of a child calculated
an appropriate range for the parental heights
What is highly suggestive of congenital GnRH deficiency
Persistent hypogonadism beyond age 18
What is hypogonadootrophic hypogonadism due to
an impaired secretion of hypothalamic GnRH and or impaired FSH and LH level
What is congenital hypogonadotrophic hypogonadism sometimes associated with
Anosmia: in Kallmann’s syndrome
Mental retardation and obesity: in Prader-Willi syndrome
Congenital adrenal hypoplasia
What is Hypergonadotrophic hypogonadism associated with
high FSH and LH levels due to a lack of negative feedback of the sex steroids
What should physical examination include
Assessment of secondary sex characteristics and staging according to the Tanner criteria
Measurement and plotting of height on a growth chart
Measurement of weight and calculation of BMI
General examination to look for any features of an underlying cause - e.g. visual field defects due to a pituitary tumour
what investigations should be included for patients with delayed puberty
FBC U&E LFT erythrocyte sedimentation rate serum LH and FSH oestradiol (girls) Testosterone (boys) prolactin free T4 and TSH
How is bone age determined
by the comparison of a radiograph of the patients bones in the left hand and wrist with the bones in a standard atlas,
This allows an assessment of skeletal maturation and the potential for future skeletal growth
What is the treatment for girls
2ug ethinylestradiol orally daily
What is the treatment for boys
50mg testosterone enanthate or cypionate IM monthly
What are side effects of testosterone therapy
acne and rarely, priapism
What is precocious puberty
the onset of secondary sexual characteristics before he age of 8 in girls or 9 in boys
What are some causes of GnRH dependent precocious puberty
Hydrocephalus hamartomas umours trauma radiotherapy inflammatory disease idiopathic
What are some causes of GnRH independent precocious puberty
Increased sex steroids from the ovaries
Increased testosterone from testes
What causes GnRH dependent precocious puberty
earlier activation of the hypothalamic pituitary-gonadal axis
What is GnRH independent precocious puberty
Autonomous endogenous secretion of sex steroids from the gonads or adrenal glands or excess exogenous sex steroids
What is testotoxicosis
an autosomal dominant disorder caused by an activating mutation of the LH receptor gene, resulting in premature Leydig cell maturation and increased testosterone secretion in boys
What is McCune-Albright syndrome
a arar disorder characterised by precocious puberty, cafe au last skin pigmentation and fibrous dysplasia of bone
What are variants of normal puberty
premature thelache and premature adrenarche
What are important parts of the medical history
Details of pubertal development: when initial changed were first noticed
Previous history of CNS disease, radiotherapy, trauma or presence of any near symptoms such as headaches or seizures
History of exposure to exogenous androgens or oestrogens
presence of abdominal pain ( ovarian disease )
What investigations are required in a patient with precocious puberty
bone age
sex steroid
LH and DSH levels
Thyroid function tests
GnRH dependent precocious puberty: brain MRI for CNS cause
GnRH independent: measure testosterone, oestradiol, dehydroepiandrosterone suplhate (elevated in adrenal tumours)
Pelvic US - ovarian cyst or tumour
What is the treatment of central precocious puberty if a cause has been found
treat it appropriately
Decision to treat depends on the predicted final adult height and physchosocial effects of the precocity
If deciding to treat, what should be given
GnRH analogue therapy
it induces the down regulation of pituitary GnRH receptors and results in the suppression of pulsatile gonadotrophin release
It slows accelerated puberty and improves final height
What should be monitored during therapy
bone density
What should children with congenital adrenal hyperplasia be treated with
glucocorticoids
What are patients with McCune-Albright syndrome treated with
drugs that inhibit gonadal steroid synthesis or action rather than surgery
What might delayed puberty be caused by
constitutional delay of growth and puberty, hypogonadotrophic hypogonadism or hypergonadotrophic hypogonadism
