Week 203 - Puberty and Adolescence Flashcards
How is the start of puberty characterised in boys?
Growth of the testicles to a volume of ~4ml (>3.5ml)
How is the start of puberty characterised in girls?
Appearance of a palpable breast bud
What is considered the concordant development of secondary sexual characteristics in boys?
Testicular enlargement > penile growth > pubic hair
What is considered the concordant development of secondary sexual characteristics in girls?
Breast bud > pubic hair > menarche
What is considered early puberty for boys and girls?
Before 8yrs for girls and before 9yrs for boys
What is the most common cause of early puberty in girls?
Idiopathic
Often the mother will have started early too - more common in Afro-Caribbean and mixed-race individuals
Which pituitary hormone is responsible for testicular and ovarian enlargement?
FSH
Why might you want to check thyroid function on a boy or girl experiencing early puberty?
Rarely, hypothyroidism may be the cause. Elevated TSH can mimic FSH and cause testicular / ovarian enlargement
If a girl <6yrs or a boy presents with central precocious puberty what investigation should you undertake?
MRI - hypothalamus, pituitary, brain
What is the 2nd most common cause of central precocious puberty in both sexes?
Tumours around the pituitary stalk and hypothalamus
What is the aim of treatment (should it be required) for central precocious puberty?
Suppression of GnRH pulsatility by use of long-acting GnRH analogues
If you found high levels of androgens in a boy but low levels of LH and FSH what further tests might you perform?
- hCG levels
- AFP (tumour marker) levels
- cranial MRI
- CT/USS (to detect / rule out possibility of tumour)
hCG is typically released from tumours in which areas?
1) pineal gland 2) liver 3) testicles
What is thelarche?
Isolated breast development in otherwise well children. It is non-progressive
What findings are likely on an ovarian USS in an individual with McCune-Albright syndrome
Ovarian cysts (oestrogen producing)
What should girls (family of) diagnosed with premature adrenarche be warned about?
The fact that some may go on to develop PCOS, especially if they gain excessive weight through puberty
What does adrenarche describe?
The normal maturation of the adrenal glands that leads androgen secretion
What are the signs of premature adrenarche?
Pubic hair, mild acne, greasy hair, body odour and mood swings
In delayed puberty what does hypergonadotrophic hypogonadism indicate?
Primary gonadal failure (e.g. menopausal)
In delayed puberty what does hypogonadotrophic hypogonadism indicate?
Central disorders
What are the principle long-term treatments for girls with simple delayed puberty?
low dose oestrogen increased gradually over 2-3 yrs with added progesterone for menstruation
What is the treatment used for girls with sparse pubic hair growth from failure of adrenarche?
Topical or injected testosterone or DHEA
What are the two predominant steroid sex hormones necessary in adolescent development?
Testosterone and oestradiol
What staging process is used to track pubertal development in adolescents?
Tanner Staging
What is the peak height velocity in boys and girls?
G - 12yrs B - 14yrs
What is central precocious puberty?
Early puberty caused by activation of hypothalamus (hypothalamic-pituitary dependent). High levels of LH and FSH
What is peripheral / precocious pseudopuberty?
Early pseudopuberty stimulated by abnormal sex steroid (androgen) secretion by adrenal hyperplasia, tumours or exogenous means. Independent of hypothalamic-pituitary axis. Low levels of LH and FSH
Precocious puberty in females is usually due to what?
Premature onset of normal puberty
Central precocious puberty in males is usually indicative of what?
Organic cause / underlying pathology
What investigation is most helpful in establishing the cause of precocious puberty in girls?
Pelvic USS
In premature onset of normal puberty in females what will you see on a pelvic USS?
Multicystic ovaries and an enlarging uterus
What investigation should take place in a male with precocious puberty?
Cranial MRI scan for intracranial tumours
What does precocious puberty in a male with small testes suggest?
An adrenal cause as LH and FSH would induce testicular growth but androgen secretion will not
