Overview
Precocious puberty is puberty occurring at an abnormally early age. In general, this is before 8 years old in girls and 9 years old in boys. It may be a variation in normal development or have an underlying cause. Precocious puberty also may reduce adult height potential due to earlier skeletal maturation.
Epidemiology
- Precocious puberty usually has an underlying cause in boys
- Precocious puberty is more common in girls
- Precocious puberty is more common if there is a family history of it present
Causes
Causes include:
- Central causes – early activation of the hypothalamic-pituitary-gonadal axis:
- Idiopathic – more common in girls, in boys, there is more likely to be an underlying cause
- Tumours (e.g. craniopharyngioma, hamartoma, optic nerve glioma)
- Radiotherapy
- Head trauma or injury (e.g. surgery, trauma, infection)
- Hydrocephalus
- Peripheral causes – puberty is independent of gonadotropin release (due to excess sex hormones):
- Gonadal tumours
- Adrenal causes (e.g. congenital adrenal hyperplasia, Cushing’s syndrome)
- McCune-Albright syndrome
- Exogenous hormone use (e.g. contraceptive pill, testosterone gels)
Investigations
Overview
Investigations may include:
- Early morning FSH and LH:
- Elevated in central causes
- Low in peripheral causes
- Sex hormone testing:
- Testosterone/oestrogen is elevated
- X-ray of the wrist:
- Estimates bone age – may show advanced bone age
- Pelvic ultrasound:
- To assess pelvic organs (e.g. ovaries) in girls
- May show cysts or tumours
- Adrenocorticotrophic hormone (ACTH) stimulation test:
- May identify congenital adrenal hyperplasia
- MRI brain:
- May show pituitary tumours
- Genetic tests:
- Considered if a genetic disorder is suspected
Management
Overview
If idiopathic, most cases of precocious puberty require no treatment. Puberty may be stopped and patients may be given growth hormone if the patient is likely to have limitations in height potential. If underlying causes are present, they are treated accordingly.
