Endocrinology Flashcards
(18 cards)
What is puberty?
It is the stage between the onset of secondary sexual characteristics and completion of physical maturity (period in which reproductive capability is attained).
When does puberty occur in girls vs. boys?
Girls = 8-13 years old Boys = 9-14 years old
What is the first sign of puberty in girls vs. boys?
Girls: breast enlargement
Boys: testicular enlargement
What is the sequence of puberty in girls?
Thelarche - adrenarche - growth spurt - menarche
What is the puberty sequence in boys?
Testicular enlargement - adrenarche - spermatogenesis - growth spurt
What is the most important factor that influences normal puberty?
Genetics
What is precocious puberty?
In girls: onset of puberty “breast enlargement” before the age of 8 years.
In boys: onset of puberty “testicular enlargement” before the age of 9 years.
(5 times more common in girls than boys)
What are the types of precocious puberty?
Central, true, GnRH-dependent:
MOST COMMON
Peripheral, pseudo, GnRH-independent:
Not a major type (outside the CNS)
Isolated forms (benign in nature):
Thelarche
Adrenarche/pubarche
What is the most common CNS disorder that causes central precocious puberty?
Hypothalamic hamartoma
What is the most common adrenal cause of peripheral precocious puberty?
Non-classical congenital adrenal hyperplasia (CAH) + adrenal tumors
What are variants of normal puberty?
- Isolated benign thelarche
- Isolated benign adrenarche (pubarche)
What is the onset of isolated benign thelarche?
Between 6 months to 4 years of age
What are some of the investigations done in precocious puberty? (To differentiate between central and peripheral types)
- Basal LH, FSH and sex steroids
- GnRH stimulation test
- hCG
- Inhibin
- 17 OHP
- Adrenal androgens
- Bone age
- MRI brain
- US of testes
- Pelvic US
- Adrenal US
- Abdominal US
What is the treatment of central precocious puberty?
- GnRH agonist
* Treatment of underlying pathology
What is the treatment of peripheral precocious puberty?
- Medroxyprogesterone acetate (provera)
- Ketoconazole ~rarely used
- Aromatase enzyme inhibitors
- Androgen antagonists
When is the classic onset of premature adrenarche?
Occurs after 5 years of age (with onset of pubic hair, axillary hair and apocrine growth)
What is the etiology of central precocious puberty in girls vs. boys?
Girls: most cases are idiopathic
Boys: most cases are pathologic (all patients need evaluation with an MRI of the head)
What is delayed puberty in girls vs. boys?
Girls: no breast tissue by 13 years of age, or no menarche by 16 years of age
Boys: no testicular enlargement by 14 years of age
