Precocious Puberty ✅ Flashcards
(115 cards)
1
Q
What can precocious puberty be defined as in girls?
A
Evidence of breast or pubic hair development in girls before the age of 8 years
2
Q
What can precocious puberty be defined as in boys?
A
Signs of testicular volume increase to at least 4ml, or other evidence of vitalisation, in boys occurring before the age of 9 years
3
Q
What can the causes of precocious puberty be divided into?
A
- Gonadotrophin dependent
- Gonadotrophin independent
4
Q
How can gonadotrophin dependent precocious puberty be differentiated from gonadotrophin independent?
A
LH and FSH are increased in gonadotrophin dependent, decreased in gonadotrophin independent
5
Q
Is FSH or LH increased more in gonadotrophin dependent precocious puberty?
A
LH
6
Q
Where does the increased LH and FSH come from in gonadotrophin dependent precocious puberty?
A
The pituitary
7
Q
What is the result of increased FSH and LH in gonadotrophin dependent precocious puberty?
A
Enlargement of the gonads
8
Q
What is the result of the enlargement of the gonads in gonadotrophin dependent precocious puberty?
A
- Increased oestrogen from the ovary
- Increased testosterone from the testis and adrenals
9
Q
Is more testosterone produced by the testis or adrenals in gonadotrophin dependent precocious puberty?
A
Testis
10
Q
What does the increased oestrogen in gonadotrophin dependent precocious puberty lead to in girls?
A
Breast development
11
Q
What does the increased testosterone in gonadotrophin dependent precocious puberty lead to in boys?
A
- Pubic hair growth
- Acne
- Body odour
12
Q
What are the causes of gonadotrophin dependent precocious puberty?
A
- Idiopathic/familial
- CNS abnormalities
- Hypothyroidism
13
Q
What can cause CNS anomalies leading to gonadotrophin dependent precocious puberty?
A
- Congenital abnormalities
- Acquired abnormalities
- Tumours
14
Q
Give an example of a congenital anomaly that can lead to gonadotrophin dependent precocious puberty
A
Hydrocephalus
15
Q
Give 3 examples of acquired causes of CNS anomalies that can cause gonadotrophin dependent precocious puberty?
A
- Post-irradiation
- Infection
- Surgery
16
Q
Give a tumour that can cause gonadotrophin dependent precocious puberty
A
Microscopic hamartomas
17
Q
What happens in gonadotrophin independent precocious puberty?
A
A gonadal or extra-gonadal source leads to increased oestrogen or testosterone
18
Q
Does the gonad shrink or enlarge in gonadotrophin independent precocious puberty?
A
Can be either
19
Q
What happens to FSH and LH in gonadotrophin independent precocious puberty?
A
They are reduced
20
Q
Why are FSH and LH reduced in gonadotropin independent precocious puberty?
A
The raised oestrogen/testosterone results in negative feedback on the pituitary, so there is reduced LH and FSH production
21
Q
What are the causes of gonadotrophin independent precocious puberty?
A
- Adrenal disorders
- Ovarian causes
- Testicular causes
- McCune Albright syndrome
- Genetic mutation of LH receptor
- Exogenous sex steroids
22
Q
Give 2 examples of adrenal disorders causing gonadotrophin independent precocious puberty
A
- Tumours
- Congenital adrenal hyperplasia
23
Q
Give 2 examples of ovarian causes of gonadotrophin independent precocious puberty
A
- Cysts
- Tumours
24
Q
Give an example of an ovarian tumour that can cause gonadotrophin independent precocious puberty
A
Granulosa cell tumours
25
Give an example of a testicular cause of gonadotrophin independent precocious puberty
Leydig cell tumour
26
What should be included in the history of a child with precocious puberty?
- Details of previous growth pattern and weight gain
- Timing of onset of features of puberty
- Presence of symptoms suggestive of intracranial pathology
- Risk factors in perinatal history
- Presence of disorders associated with sexual precocity
- Drug history
- Family history
- Extent to which early onset of puberty is impacting on child's psychosocial wellbeing
27
What features of puberty should be asked about in the history for precocious puberty?
- Acne
- Body odour
- Breast, pubic hair, and genital development
- Increased vaginal secretions or periods
28
What risk factors in the perinatal history should be asked about in the history for precocious puberty?
- Prematurity
- Intraventricular haemorrhage
- Small for gestational age
29
Give 2 disorders that are associated with sexual precocity?
- McCune-Albright syndrome
| - Neurofibromatosis
30
Give a drug that can be associated with precocious puberty
Oxymethalone
31
What should be asked about in the family history of precocious puberty?
Timing of maternal menarche
32
What should be noted on examination in a child with precocious puberty?
- Height
- Weight
- Tanner stage
- Measurement of testicular volume
- Features of other disorders, e.g. hyperthyroidism, McCune-Albright syndroome, neurofibromatosis
33
How should testicular volumes be measured?
Using a Prayer orchidometer
34
What features on examination may be suggestive of neurofibromatosis?
- Cafe-au-lait patches
| - Axillary freckling
35
What examination should be performed to look for signs of raised ICP?
- Fundoscopy
| - Visual field examinations
36
What investigations might be considered in precocious puberty?
- XR of left wrist
- Pelvic ultrasound
- Basal blood sample
- LHRH stimualtion test
- MRI of hypothalamopituitary axis
37
Why might a XR of the left wrist be done in precocious puberty?
To calculate bone age
38
Why might bone age be useful in precocious puberty?
Is a guide to the extent of physiological advance
39
What information may be obtained from a pelvic USS in precocious puberty?
- Size of uterus
- Extent of endometrial response
- Size of ovaries
- Presence of ovarian follicles
40
What hormones may be measured in basal blood samples in precocious puberty?
- Testosterone
- Oestrogen
- LH and FSH
- Adrenal androgens
41
What adrenal androgens may be measured in precocious puberty?
- DHEAS
- Androstenodione
- 17-OH progesterone
42
What is measured in a basal blood sample for precocious puberty in boys?
Testosterone
43
What is measured in a basal blood sample for precocious puberty in girls?
Oestradiol
44
What is the purpose of a basal blood sample for testosterone/oestradiol in precocious puberty?
Confirm biochemical evidence of puberty
45
Why can measurement of LH and FSH be helpful in precocious puberty?
Can distinguish between gonadotrophin-dependent and independent causes
46
Why might adrenal androgens be measured in precocious puberty?
To exclude a defect in adrenal hormone biosynthesis
47
What other investigation might be useful in excluding a defect in adrenal hormone biosynthesis?
A urinary steroid metabolite profile
48
When is a LHRH stimulation test indicated in precocious puberty?
If basal gonadotrophins are low and sex steroids are high
49
What does low basal gonadotrophins and high sex steroids indicate?
Gonadotrophin-independent precocious puberty
50
Why is a LHRH stimulation test indicated when there is suspected gonadotrophin-independent precocious puberty?
To confirm the lack of gonadotrophin response in this scenario
51
When is a MRI of the hypothalamopituitary axis required in precocious puberty>
In gonadotrophin-dependent precocious puberty (especially in boys)
52
Why is an MRI of the hypothalamo-pituitary axis required in gonadotrophin-dependent precocious puberty?
To exclude intracranial tumour
53
What is true central precocious puberty defined as?
Early onset puberty which has been stimulated by activation of the hypothalamo-pituitary axis
54
Is true central precocious puberty more common in boys or girls?
Girls
55
What is the most common cause of true central precocious puberty in girls?
Usually unknown
56
What is the most common cause of true central precocious puberty in boys?
Consequence of intracranial pathology
57
What intracranial pathologies can cause true central precocious puberty in boys?
- Tumours in the region of the hypothalamus
| - Following previous cerebral trauma that occurred in the perinatal period
58
What tumours can occur in the region of the hypothalamus?
- Gliomas
- Astrocytomas
- Benign hamartomas
59
Give a cause of cerebral trauma occurring in the perinatal period that can lead to true central precocious puberty
Periventricular haemorrhage
60
What does a diagnosis of true central precocious puberty require?
- Measurement of serum oestradiol concentrations
| - Usually a LHRH stimulation test
61
Why is a LHRH stimulation test usually required to diagnose true central precocious puberty?
To demonstrate activation of gonadotrophin
62
What other investigations may be done in true central precocious puberty?
- Left wrist x-ray
- Pelvic ultrasound in girls
- MRI
63
What will the left wrist x-ray show in true central precocious puberty?
Advanced bone development
64
What may a pelvic USS show in true central precocious puberty in girls?
- Ovarian enlargement with follicles
| - Uterine enlargement
65
Why is an MRI done in true central precocious puberty?
To exclude intracranial haemorrhage
66
What does treatment of true central precocious puberty require?
GnRH analogue therapy
67
How does GnRH analogue therapy work in true central precocious puberty?
It suppresses gonadotrophin and oestradiol secretion
68
What is the purpose of treating true central precocious puberty?
- Prevent psychosocial effects of advancing puberty
| - Maximise potential adult height
69
How do GnRH analogues work?
They bind to GnRH receptors
70
What effect do GnRH analogues have when they bind to GnRH receptors?
Initially stimulate them, but thereafter achieve downregulation
71
What side effect may be produced by down-regulation of GnRH receptors by GnRH analogues?
Temporary episode of vaginal blood loss
72
What causes a temporary episode of vaginal blood loss with downregulation of GnRH receptors?
Faling oestradiol levels
73
How long should GnRH treatment be continued for?
Until the child and family are comfortable to allow puberty to progress, or until the child has achieved the normal age-range for the stage of puberty that has been achieved
74
What happens to FSH and LH in gonadotrophin independent precocious puberty?
They are reduced
75
What causes androgen-mediated precocious puberty?
Excess androgen secretion
76
What does excess androgen secretion lead to?
Virilization, including pubic and axillary hair development
77
What can excess androgen secretion lead to in severe cases?
- Genital maturation in boys
| - Cliteromegaly in girls
78
What is the most common form of androgen-mediated precocious puberty?
Exaggerated adrenarche
79
What is exaggerated adrenarche associated with?
The physiological activation of the adrenal gland from the age of 6 years
80
What does the physiological activation of the adrenal gland from the age of 6 years produce?
Relatively weak androgens such as DHEAS (dehydroepiandrosterone) and androstrenedione
81
How does the activation of the adrenal gland at age 6 usually clinically manifest?
Usually unnoticed
82
How does exaggerated adrenarche present?
- Production of small amounts of pubic or axillary hair
| - Sometimes increased skin secretions and body odour
83
How is exaggerated adrenarche managed?
- No specific therapy required
| - Reassurance
84
What is exaggerated adrenarche associated?
- Reduced brith weight
| - PCOS
85
What is it important to distinguish exaggerated adrenarche from?
Congenital adrenal hyperplasia (CAH)
86
How is exaggerated adrenarche distinguished from CAH?
- Measurement of 17OH-progesterone
| - Urinary steroid metabolite profile
87
In what form of CAH will there be abnormalities in 18OH-progesterone levels?
21-hydroxylase deficient variant
88
In what form of CAH will there be abnormalities in urinary steroid metabolite profiles?
Virilising forms
89
What form of CAH is more common?
21-hydroxylase deficient variant
90
What are virilising forms of CAH usually associated with?
Significant virilisation including cliteromegaly and evidence of growth spurt with marked advance in bone age
91
What tumours can produce androgen-mediated precocious puberty?
Virilising tumours of the ovarian or adrenal glands
92
What is required to treat virilising tumours producing precocious puberty?
Surgery
93
Give 2 causes of gonadotrophin-independent precocious puberty caused by genetic mutations
- Testotoxicosis
| - McCune-Albright syndrome
94
What causes testotoxicosis?
Autosomal dominant activating mutations of the LH receptor
95
What gender is affected by testotoxicosis?
Males
96
What causes precocious puberty in McCune-Albright syndrome?
Activating mutations of a gene involved in G-protein coupled signalling
97
What gender can be affected by McCune-Albright syndrome?
Both
98
Will GnRH therapy work in gonadotrophin independent precocious puberty?
No
99
Why will GnRH therapy not work in gonadotrophin-independent precocious puberty?
Because the defect lies distal to the action of GnRH
100
What does therapy for gonadotrophin-independent precocious puberty use in girls?
Anti-oestrogens
101
What does therapy for gonadotrophin-independent precocious puberty use in girls?
- Androgen synthesis blockers
- Aromatase inhibitors
- Androgen receptor blockers
102
Give 2 androgen synthesis blockers
- Cyproterone
| - Ketoconazole
103
Give an aromatase inhibitor
Testolactone
104
Give 4 androgen receptor blockers
- Spironolactone
- Ketoconazole
- Cyproterone
- Flutamide
105
Is premature thelarche common?
Relatively
106
What is premature thelarche?
Isolated breast development in young girls 6-12 months in the absence of any wider evidence of puberty or rising oestradiol concentration
107
What happens on LHRH stimulation testing in premature thelarche?
There is a FSH response
108
What is the mechanism of breast development in premature thelarche?
Unclear
109
What treatment is required for premature thelarche?
None - condition benign and self-limiting, no therapy required
110
What is thelarche variant?
A similar phenomenon to premature thelarche that occurs at 5-8 years
111
What might thelarche variant be associated with?
- Slight increase in height velocity
| - Brief period of vaginal blood loss
112
What is premature menarche?
Cyclical vaginal bleeding occurring in the absence of wider signs of puberty
113
At what age does premature thelarche occur?
5-8 years
114
What is the mechanism of premature menarche?
Unknown
115
What are the differential diagnoses for premature menarche?
- Vulvovaginitis
- Vaginal trauma
- Foreign bodies
- Tumours
- Sexual abuse
