Disorders of puberty Flashcards
What is precocious puberty?
Development of secondary sexual characteristics before 8 years in girls and 9 years in boys
More common in obese children
Can be peripheral or central:
- Peripheral: gonadotrophin independent
- Central: due to early HP-gonad axis
Discuss central precocious puberty
90% cases idiopathic
CNA lesions account for 10% cases
- Infection e.g. encephalitis
- Tumour
- Trauma
- Epilepsy, hydrocephalus
Discuss peripheral precocious puberty
Oestrogen secreting tumour
McCune-Albright syndrome: precocious puberty, cystic bone lesions, cafe au lait spots
Iatrogenic (consumption of oestrogen)
- Hypothyroidism
- Congenital adrenal hyperplasia
What is McCune Albright syndrome?
Genetic disorder causing
- Precocious puberty
- Skin lesions e.g hyper or hypopigmentation
- Fibrous dysplasia (benign bone condition in which abnormal fibrous tissue develops in place of normal bone)
Discuss diagnosis of central peripheral puberty
High LH, LH increases with GnRH stimulation
Pubertal levels of oestradiol and testosterone
Pelvic USS shows enlarged uterus and ovaries
Brain MRI: 10% will have a lesion
Discuss diagnosis of peripheral precocious puberty
LH low or prepubertal, absent LH response to GnRH stimulation, pubertal or very high levels of oestradiol or testosterone, enlarged uterus and ovaries, brain MRI normal
Investigations for precocious puberty
GnRH stimulation tests: LH raised
Bone scan: x-ray of wrist as bone age reflects oestrogen levels
Pelvic USS: exlude ovarian tumour
MRI if intracranial lesion suspected
Management of precocious puberty
Idiopathic central PP: GnRH agonists which reduce LH and FSH production via negative feedback
Surgery: ovarian tumours or intracranial lesions
Why does precocious puberty cause short stature?
Oestrogen causes premature fusion of epiphyseal plate in long bones
What is delayed puberty?
Absence of secondary sexual characteristics by 16 years
Causes of delayed puberty
- Gonadal dysgenesis: Turner’s
- Kallmanns syndrome
- Prolactin secreting adenoma
- Secondary delay: Sheehan syndrome
- Androgen insensitivity
Causes of delayed puberty with short stature
Turner’s, Prader Willi, Noonan’s
Causes of delayed puberty without short stature
Kallmann’s, Klinefelter’s
What is hirsutism?
Excess hair growth in male distribution in women
Most often caused by PCOS or benign conditions but can be due to androgen secreting tumours, Cushing’s, acromegaly and some drugs
Hirsutism and additional signs of hyperandrogenism are worrying: acne, deep voice, enlarged clitoris, amenorrhoea
What is the scoring system for hirsutism?
Ferriman-Gallwey scale
Management of hirsutism
COCP: dianette
Cyproterone acetate: antiandrogen
What is hypogonadism?
Term used to describe non functioning ovaries leading to
- Failed oestrogen production which leads to defective primary or secondary sexual development
- Failed oocyte development
Causes of hypogonadism
Defect in ovaries = primary ovarian dysfunction
Defect in brain = primary hypothalamic pituitary dysfunction
What is hypergonadotrophic hypogonadism?
High levels of GnRH or LH/FSH due to low levels of oestrogen (low oestrogen levels means there is nothing to tell the hypothalamus/ pituitary to stop FSH/LH production)
Occurs as a result of primary gonadal dysfunction
Most common causes of hypogonadism
Gonadal dysgeneis: Turner’s
Kallman syndrome
Sheehan syndrome
Prolactin secreting adenoma
Chemo/ xRT, infection
Autoimmune
What is Turner’s syndrome?
Complete absence of one X chromosome
Affects 1 in 2500 live births and accounts for >50% cases of gonadal dysgenesis
Patients present in late teens with absence of puberty and recognisable phenotype of low set ears, large number of moles, wide-spaced nipples, short webbed neck and short stature
Associated with coarctation or aorta, spina bifida and deafness
What is Kallmann’s syndrome?
Hypogonadotrophic hypogonadism - caused by failure of GnRH to hypothalamus therefore LH and FSH not secreted
Causes anosmia and midline facial anomalies
Clinical features of hypogonadism
Depends on timing of ovarian failure
If never functioned: delayed puberty and absence of secondary sexual characteristics
Failure later in life > early menopause
Typically presents as amenorrhoea or difficulty conceiving
Management of hypogonadotrophin hypogonadism
Behaviour modification: hypothalamic dysfunction can be caused by stress, excessive exercise or weight loss
Medication: HRT to promote breast development and maintain bone health
Surgery: excise tumours, intrabdominal gonads removed in patients who have Y chromosomes because can cause malignancy
Development of secondary sexual characteristics may occur but fertility may not be possible
What is galactorrhoea?
Abnormal lactation
Causes: prolactinoma, decreased DA secretion which removed inhibition of prolactin secretion e.g. due to tumours, head trauma, DA antagonists
Most cases associated with hyperprolactinaemia due to decreased DA inhibition or prolactin secreting tumours
40% cases no cause found
Diagnosis of galactorrhoea
Detailed drug hx
Headaches + visual disturbance - tumour
Exclude recent pregnancy as discharge can occur 6 months after stopping feeding
Investigations for galactorrhoea
Bloods: measure serum prolactin
Exclude hypothyroidism and CKD - both can cause galactorrhoea
Image pituitary if prolactin levels +++
