Precocious puberty

Question 1

Define precocious puberty in girls

Answer 1

Onset of secondary sexual characteristics (pubic hair or breasts) before age 8 or menses before age 9.


Question 2

incidence of precocious puberty

Answer 2

4-5% of girls, much less common in boys

Question 3

Classify precocious puberty in girls into two (2) categories.

Answer 3

Central/ gonadotrophin dependent

Peripheral/ gonadotrophin independent

Question 4

What are the eitologies of precocious puberty?

Answer 4

Central:

• structural brain abnormality including hydrocephalus
• pituitary tumour producing LH and FSH
• idiopathic (hereditary)
• Acquired ( irridation, trauma, infection)

Peripheral:

• Ovarian: Oestrogen producing ovarian tumour (granulosa cell), androgen producing tumour (sertoli leydig)
• Adrenal: androgen producing tumour , CAH, Cushings
• McCune Albright Syndrome
• Hypothyroidism
• exogenous administration of steroids: OCP, anabolic steroids

Question 5

History and examination for precocious puberty:

Answer 5

History:

• What symptoms: age of onset and details and rate of progression of secondary sex characteristics, age of onset of menses
• Timing and age of any recent growth spurt
• Any medications she is on? Any chance she could be taking the COCP ( mothers stash) or taking any exogenous steroids
• FH: what age did her older sisters/ mother/ grandmother go through puberty

Examination:
- measure height, weight, head circumference
- Neurological examination including fundoscopy and visual fields
Abdominal examination: any palpable abdominal mass
Skin - ? any café au lait spots
Tanner staging
- breast development:
- pubic hair:
external genitalia: fat pad of mons, enlargement of clitoris or
signs of virulisation

Question 6

What biochemical investigations would you do to determine cause of precocious puberty?

Answer 6

Basal gonadotropin (LH, FSH) levels.
• GnRH stimulation tests
• Estradiol/testosterone levels.
• Adrenal steroids- DHEA-S, 17OH -progesterone, androstenedione • (raised in adrenal tumors,congenital adrenal hyperplasia)
• ACTH stimulation tests - congenital adrenal hyperplasia • Free thyroxine and TSH levels - Hypothyroidism
• Serum Prolactin-raised in prolactinoma, hypothyroidism

Question 7

Imaging for determining cause of precocious puberty?

Answer 7

Xray of left wrist for bone age Imaging • CT /MRI brain
• CT adrenals.
• Pelvic ultrasound-shape, size of uterus, endometrial thickness, ovarian morphology