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Stage 2: Human Deveopment > Paeds: Precocious and Delayed Puberty > Flashcards

Paeds: Precocious and Delayed Puberty Flashcards

1
Q

What is precocious puberty?

A
  • Early puberty 2-2.5 SD earlier than the population norms
  • May range from variants of normal development to pathologic conditions
  • True central precocious puberty is quite rare
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2
Q

What is precocious puberty in boys?

A
  • Before 9 years

- First sign = increase in testicular volume from 3 to 4 ml

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3
Q

What is precocious puberty in girls?

A
  • Before 8 years

- First sign = breast budding

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4
Q

What should you do in precocious adrenarche (body odour, pubic, axillary hair)?

A
  • May be normal

- Need to rule out pathology

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5
Q

What do you need to know if someone is exhibiting precocious puberty?

A
  • Is the child too young to have reached the pubertal milestone in question?
  • What is causing the early sexual development?
  • Is therapy indicated? If so, what therapy?
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6
Q

Is precocious puberty more common in boys or girls and what does this mean?

A
  • 5-10x more common in girls

- Therefore more worried if a girl has late puberty and a boy has early puberty bc usually the other way round

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7
Q

What are the features of true central precocious puberty

A

1) Gonadotropin dependent i.e. LH and FSH kick in early
2) Early maturation of HPG axis
3) Correct sequential maturation
4) Pathologic in 4-75% of boys and 10-20% (idiopathic) in girls
5) Sexual characteristics are appropriate for the child’s gender

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8
Q

What are the features of peripheral precocity/precocious puberty?

A

1) Gonadotropin independent - excess sex hormones without stimulation from pituitary (wrong order)
2) Excess secretion of sex hormones
3) Non-sequential maturation e.g. periods before breast buds, small testes large penis
4) Isosexual or contrasexual - can be either for right or wrong sex e.g. breast buds in boy

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9
Q

What are causes of excess sex hormones in peripheral precocious puberty?

A
  • Gonads
  • Adrenal glands
  • Exogenous sources of sex steroids
  • Ectopic production of gonadotropin from a germ cell tumour
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10
Q

What are benign puberal variants causing precocious puberty?

A

1) Premature thelarche
2) Precocious adrenarche - isolated androgen-mediated sexual characteristics
3) Early normal puberty - variant of normal puberty

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11
Q

What are the signs/symptoms of central precocious puberty in girls?

A

1) Early growth spurt (accelerated linear growth) e.g. growing 11cm/year at age 6 (growing too much for age)
2) Advanced bone age
3) Uterus structure changes - initially tubular but under influence of oestrogen it becomes broader at top
4) Pubertal levels of LH/FSH

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12
Q

Why can boys present delayed with central precocious puberty?

A

Bc only see increased testicular growth

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13
Q

What is the consequence of advanced bone age in precocious puberty?

A
  • Under the influence of hormones, bones grow faster but bones plates fuse prematurely
  • Therefore they stop growing v early so mainly under 5ft as an adult
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14
Q

What investigations can you in central precocious puberty?

A

1) FSH and LH levels (pubertal levels)
2) Pelvic US to see change in uterus structure
3) Test = give GnRH and see if they respond in a pubertal way or not e.g. if LH/FSH and sex hormones increase (shouldn’t happen before puberty)

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15
Q

Why do you need to treat and block central precocious puberty

A

Young children find it hard to deal with adolescent hormones which are hard enough as an adolescent e.g. 5-6 year old can’t deal with this

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16
Q

What are causes of true central precocious puberty?

A

1) Idiopathic - 80-90% girls, 25-60% boys
2) CNS lesions (neurogenic) - any kind of brain damaged leads to increased likeliness of switching on the axis sooner
3) Genetics
4) Previous excess sex steroid exposure (priming from adrenarche)
5) McCune Albright syndrome
6) Extreme prematurity - causing micro bleeds in brain
7) Pituitary gonadotropin-secreting (LH and FSH) tumours leading to elevated levels of LH and FSH - v rare in children, usually prolactin

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17
Q

What are causes of neurogenic true central precocious puberty?

A

1) Hamartomas - benign tumour which causes gelastic epilepsy (uncontrolled laughter, epileptic fit)
2) CNS tumours e.g. astrocytomas, ependymomas, pinealomas, optic and hypothalamic gliomas
3) CNS irradiation
4) CNS lesions e.g. hydrocephalus, cysts, trauma, CNS inflammatory disease, congenital midline defects
5) Epilepsy

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18
Q

What are genetic causes of true central precocious puberty?

A

1) Gain of function mutation in the KISS1 and KISS1R

2) Loss of function mutation in MKRN3

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19
Q

What is McCune Albright syndrome?

A

Triad of

1) Peripheral precocious puberty
2) Irregular cafe au lait spots
3) Fibrous dysplasia of bone
- Sequence of pubertal progression may be abnormal, often presenting with vaginal bleeding

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20
Q

What are causes of peripheral precocity in girls?

A

1) Ovarian cysts (most common)

2) Tumours (rare)

21
Q

Describe how ovarian cysts cause peripheral precocity

A
  • Breast development, vaginal bleeding - ovarian torsion
  • Drop in oestrogen causes bleed
  • Dominant follicle secretes oestrogen
22
Q

Describe how tumours cause peripheral precocity in girls

A
  • Ovarian granulosa (follicular) cell tumours cause isosexual precocity
  • Sertoli/Leydig cell tumours, pure Leydig cell tumours, gonadoblastoma all cause contrasexual precocity (virilisation)
  • e.g. in 3 year old look for tumour secreting androgen
23
Q

What are causes of peripheral precocity in boys?

A

1) Leydig cell tumours
2) Germ cell tumours
3) Familial male-limited precocious puberty (testotoxicosis)

24
Q

Describe leydig cell tumours

A
  • Asymmetric testicular enlargement - one large one with a tumour
  • Testosterone secreting tumour
  • Benign
  • Treatment = radical orchiectomy
25
Q

Describe germ cell tumours

A
  • Secretion hCG which activates LH receptors on Leydig cells leading to testosterone production
  • Can be located in gonads, brain, liver, retroperitoneum or anterior mediastinum
  • Testicular size smaller than expected for the testosterone concentration in plasma and puberty staging
  • Problem with LH receptor
26
Q

What is familial male-limited precocious puberty (testotoxicosis)

A

An activating mutation in the LH receptor gene causing premature Leydig cell maturation and testosterone secretion

27
Q

What are causes of peripheral precocity in boys and girls?

A

1) Primary hypothyroidism
2) Exogenous sex steroids
3) Adrenal pathology

28
Q

How does primary hypothyroidism lead to peripheral precocity?

A
  • Thyroid isn’t working properly, no negative feedback from T4/T3 so there is high TSH
  • The high serum TSH levels stimulate the FSH receptor (cross/reactivity) bc they have a common alpha subunit
  • This causes early breast development, galactorrhoea, recurrent vaginal bleeding and premature testicular enlargement
29
Q

What are examples of exogenous sex steroids that lead to peripheral precocity?

A
  • Creams, ointments, sprays e.g. oestrogen cream for someone in menopause
  • Contamination from food with hormones - phytoestrogens (soy) - would need A LOT
30
Q

How does adrenal pathology lead to peripheral precocity?

A

1) Androgen secreting tumours and enzymatic defects in adrenal steroid biosynthesis (CAH) cause virilisation in both girls and boys
2) Adrenal oestrogen secreting tumours cause feminisation
- Premature pubarche may be the presenting feature

31
Q

Describe the features of premature thelarche

A
  • Idiopathic - benign, no pathology
  • Occurs around 2 years of age
  • Waxes and wanes - does not progress
  • Isolated breast development not beyond Tanner stage 3
  • Absence of other secondary sexual characteristics
  • Normal height velocity and bone age (near normal)
  • LH and FSH in normal range
  • Usually monitor children from a year and if it doesn’t get worse then ok
  • Possible cause is that girls are v sensitive to the small amount of oestrogen produced by oocytes in their body
32
Q

Describe the features of premature adrenarche

A
  • Pubarche (pubic and/or axillary hair)
  • Acne, body odour
  • Mild increase in growth velocity and advanced bone age (if > 2SD requires further investigation)
  • Mild elevation in serum DHEAS for age
  • More common in girls, AC and Hispanic females and patients with obesity and insulin resistance
  • Risk factor for developing PCOS later in life
  • Can cause priming result in TCPP (v rare)
  • Best way to measure is in urine (24h urine steroid profile), not blood
33
Q

How would you evaluate/investigate precocious puberty?

A

1) History and physical examination - FH, cafe au lait lesions, penis/testicle growth, hair but no breast budding etc
2) Basal serum LH, FSH, oestradiol, testosterone
3) GnRH stimulation test, serum/urine adrenal steroids
4) TSH, beta HCG, AFP (tumour)
5) Imaging of pituitary gland, brain MRI, pelvic US, bone age

34
Q

How do you treat precocious puberty?

A

Depends on cause

1) Reassurance if normal benign variation
2) Gonadotropin dependent - block with GnRH analogues
3) Gonadotropin independent - anti-androgens/aromatase inhibitors
4) GnRH agonists - stimulate pituitary gland and then it switches itself off from overproducing, puts you on pause e.g. no further growth of breasts/testicles
5) Discuss risks e.g. psychological, dealing with sex hormones, periods

35
Q

What are the features of delayed puberty in girls?

A

1) No breast development by 13
2) No pubic hair by 14
3) No menarche by 16 without secondary sexual characteristics
4) More than 5 years between thelarche and menarche

36
Q

What are the features of delayed puberty in boys?

A

1) Testicular volume < 14ml by 14
2) No pubic hair by 15
3) Takes more than 5 years to finish penile and testicular growth

37
Q

What is the main cause of delayed puberty?

A

Gonadal failure (hypogonadism)

38
Q

What are the two types of hypogonadism?

A

1) Primary = hypergonadotropic hypogonadism

2) Secondary = hypogonadotropic hypogonadism

39
Q

Where is the problem in hypergonadotropic hypogonadism?

A

Problem at levels of goods (high gonadotropins)

40
Q

Where is the problem in hypogonadotropic hypogonadism?

A

Hypothalamus/pituitary (normal or low gonadotropins)

41
Q

What are the congenital causes of primary hypogonadism?

A

1) Chromosomal anomalies e.g. Turner syndrome (streak, not properly functioning ovaries, so high LH/FSH bc no negative feedback), Klinefelter syndrome
2) Synthesis and action of sexual steroids
3) Testicular regression syndrome - damaged vasculature to testes (v rare)

42
Q

What are the acquired causes of primary hypogonadism?

A

1) Surgery or trauma (more common with testes)
2) Chemo/radiotherapy
3) Autoimmune
4) Post infection e.g. mumps in boys
5) Metabolic e.g. galactosemia - start developing properly and then cease (can cause POF)

43
Q

What are the congenital causes of secondary hypogonadism?

A

1) Craniofacial anomalies/midline defects .g. septic optic dysplasia (affects pituitary)
2) GnRH deficit due to e.g. Kallman, Prader-Willi, Laurence Moon, CHARGE, hormone deficit, alteration of GnRH gene receptor
3) Idiopathic

44
Q

What are the acquired causes of secondary hypogonadism?

A

1) Function loss e.g. eating disorders, athletes, chronic illness, Cushing’s, diabetes, hyperprolactinaemia, hypothyroidism
2) Physical - CNS tumours, infiltrative disease, head trauma, head radiation

45
Q

Describe the features of constitutional delay of growth and puberty

A

1) Aetiology unknown - rule out other causes
2) FH, esp. father
3) Boys more affected than girls (but also girls less likely to present bc less worried about being short)
4) Normal birth weight and height
5) Growth slows down by 2-3 years to below 3rd centile
6) Significantly delayed bone age
7) Boys often present at 12-13 worried about height and lack of pubertal signs
8) However they have an extra long period of time with GH and bones fuse later so are often taller than normal when adults

46
Q

What do you do to diagnose delayed puberty?

A
  • Clinical history
  • Growth charts
  • FH
  • Exercise, chronic illness, food habits
  • LH, FSH, testosterone, oestrogens, prolactin, TSH, karyotype
  • Bone age, brain MRI, pelvic US
  • Secondary hypogonadism looks the same as delayed puberty on the outside - only time can tell as one will never go into puberty
47
Q

How do you manage delayed puberty?

A

1) Watchful waiting - reassurance to parents and young person
2) Psychological assessment - bullying
3) Anabolic steroids (oxandralone) for height
4) Short term sex hormone therapy to kick start puberty

48
Q

Describe treatment with anabolic steroids (oxandralone) to treat delayed puberty

A
  • Used in boys < 14 years old who are pre-pubertal/early pubertal with short stature
  • Increased growth velocity
  • No virilisation and no advancement in bone age
  • Growth without going into puberty - normally growth is the main concern
49
Q

Describe short term sex hormone therapy to treat delayed puberty

A
  • Used in boys > 14 and girls > 12 with no signs of puberty and expressing considerable anxiety about their delay
  • Kick starts puberty
  • e.g. given every month for 3 months and then after that they are fine, just needed something to start the process

Stage 2: Human Deveopment (34 decks)

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