Precocious Puberty Flashcards
Define
Early normal puberty and precocious puberty are distinct conditions:
Early normal puberty (Girls Order of onset: “Boobs, Pubes, Grow, Flow”):
* Girls = 8 < age ≤ 10
* Boys = 9 < age ≤ 12
Precocious puberty (Girls “8” looks like boobs):
- Girls = age <8yo
- Boys = age <9yo
Puberty is determined by:
Girls = breast development (Tanner’s 5 breast development stages)
Stage 1 = flat
Stage 2 = buds appear, breast and nipple raised, fat forms, areola enlarges
Stage 3 = breasts grow larger (conical à rounder shape)
Stage 4 = nipple and areola raise above mound; menstruation within 2 years of this stage
Stage 5 = mature adult breast is rounded, and only nipple is raised
o Boys = testicular development >4mL (Prader’s orchidometer)
Causes of precocious puberty
Gonadotrophin-Dependant Precocious Puberty [GDPP]
* Premature activation of HPG axis
* Idiopathic (no cause found in 80% girls and 40% boys)
* CNS abnormalities (tumours, trauma, central congenital disorders)
Gonadotrophin-Independent Precocious Puberty [GIPP] – 20% of PP:
* Early puberty from increased gonadal activation independent of HPG
* Ovarian – follicular cyst, granulosa cell tumour, Leydig cell tumour, gonadoblastoma
* Testicular – Leydig cell tumour, testotoxicosis (defective LH-R function; a familial GIPP)
* Adrenal – CAH, Cushing’s syndrome
* Tumours – b-hCG-secreting tumour of liver, tumours of ovary, testes, adrenals
* McCune-Albright syndrome – a multiple endocrinopathy of thyrotoxicosis, Cushing’s, acromegaly
· S/S: polyostotic fibrous dysplasia, café-au-lait spots, ovarian cysts
* Exogenous hormones – COCP, testosterone gels
Benign isolated precocious puberty – these are all generally self-limiting:
Premature thelarche [isolated breast development before 8yo; normally between 6m and 2yo]:
* May occur in those <3yo à spontaneously regresses (from maternal oestrogen early on)
* Features of premature thelarche:
* Absence of other pubertal signs Normal growth
* Normal USS of uterus Rarely progress past Tanner stage 3
Premature pubarche/adrenarche [isolated pubic hair development before 8yo (girls) or 9yo (boys)]:
* Due to early adrenal androgen secretion in middle childhood
* More common in Asian or Afro-Caribbean
* Premature menarche [isolated vaginal bleeding before 8yo]
Investigations
Females [normally not of concern] → pelvic USS
- Premature onset of normal puberty à multicystic ovaries and enlarging uterus
- Rule out gonadal tumour, cysts
Males [organic cause] → examination of testes, MRI (intracranial tumours), GnRH-stimulated LH/FSH
* Most commonly has an organic cause
* N.B. if LH and FSH are normal, any virilisation has a primary cause (i.e. adrenal hyperplasia)
* CAH -> initial growth spurt (tallest in class) à premature bone fusion (smallest in class)
Prader’s orchidometer measurement and examination of testes:
* Bilateral enlargement → GDPP (intercranial lesion; i.e. optic glioma in NF1)
* Unilateral enlargement→ gonadal tumour
* Small testes → tumour or CAH (adrenal cause)
General investigations:
GOLD-STANDARD: GnRH stimulation test – suppressed LH/FSH if G-independent
· FSH, LH low = GIPP à other tests…
· FSH, LH high = GDPP à other tests…
Wrist XR (non-dominant) for skeletal age
General hormone profile -> basal LH/FSH, serum testosterone and oestrogen
Urinary 17-OH progesterone if CAH suspected
Management
Management -> REFER TO PAEDIATRIC ENDOCRINOLOGIST:
If GDPP with no underlying pathology, often no treatment is required
Gonadotrophin-Dependent Precocious Puberty (exclude neoplasms; n.b. 90% females no identifiable cause)
* GnRH agonist (e.g. leuprolide) + GH therapy:
· GnRH agonists overstimulate pituitary à desensitisation à arrest puberty
· GH therapy used as GnRH agonists can stunt growth
- GnRH agonist + cryproterone (anti-androgen)
· Supresses peripheral androgen action
Gonadotrophin-Independent Precocious Puberty (exclude neoplasms):
- McCune Albright or Testotoxicosis: 1st: ketoconazole or cyproterone; 2nd: aromatase inhibitors
- CAH: hydrocortisone + GnRH agonist
