Precocious Puberty (Early Puberty)
This is a relatively common condition seen in our children and young people’s clinics when puberty starts in one way or another 2-3 years earlier than peers and siblings. This can be divided up into whether it is true puberty i.e. normal but early, or is disordered puberty where the physical changes happen in the wrong order and too early, which is much more concerning.
For many years, puberty was designated as precocious in girls younger than 8 years; however, studies have come to indicate that signs of early puberty (breasts and pubic hair) are often present in girls (particularly Black girls) between ages 6-8 years. For boys, the onset of puberty before age 9 years is still considered precocious.
Why Should I Be Concerned?
Early-onset of puberty can cause several problems. The early growth spurt initially can result in tall stature, but rapid bone maturation can cause growth in height to stop too early and may result in short adult stature.
The early appearance of breasts or menstruation in girls and increased libido in boys can cause emotional distress for some children.
If after a thorough and expert investigation there is a need to treat the specific cause, then this is an area where a Specialist Paediatric Endocrinologist is needed.
What To Look For
Precocious puberty in girls is characterised as follows:
The first and most obvious sign of early puberty is usually breast enlargement, which may initially be unilateral
Pubic and axillary hair may appear before, at about the same time as, or well after the appearance of breast tissue; axillary odour usually starts about the same time as the appearance of pubic hair
Menarche is a late event and does not usually occur until 2-3 years after the onset of breast enlargement
The pubertal growth spurt occurs early in female puberty and usually is evident by the time of initial evaluation
Precocious puberty in boys is characterised as follows:
The earliest evidence of puberty is testicular enlargement, a subtle finding that often goes unnoticed by patients and parents
Growth of the penis and scrotum typically occurs at least a year after testicular enlargement
Accelerated linear growth (the pubertal growth spurt) occurs later in the course of male puberty than in female puberty but often takes place by the time other physical changes are noted
Although there is a chance of finding abnormalities on investigation in girls with signs of puberty before 8 years of age and in boys before 9 years of age, the vast majority of these children with signs of apparent puberty have variations of normal growth and physical development and do not require laboratory testing, bone age X-rays, or any form of treatment.
So What’s Normal and What’s Abnormal?
Precocious puberty may be:
True - the course and pattern are normal, but early
– also called central precocious puberty. This results from the early release of the pulses of the hormones which stimulate puberty. This is the secretion of gonadotrophin-releasing hormone (GnRH) (gonadotrophin dependent precocious puberty or GDPP) as this involves the normal but premature activation of the hypothalamic-pituitary-gonadal (HPG) axis – the important thing about this is that the process can be halted temporarily by a drug which blocks the release of the hormone (GnRH) which is driving puberty.
Pseudo - the pattern is abnormal and at any age
- This is where the signs of puberty occur in the wrong order as well as earlier than normal. This is related to increased sex steroid production, which is independent of GnRH (gonadotrophin-independent precocious puberty or GIPP).
Breast development and increased rate of growth before age 8 in girls and development of the penis and testes in boys before age 9 suggests precocious puberty.
In boys, the observation of precocious puberty is much less frequent than in girls and has a higher risk of being caused by abnormal processes, and therefore requires urgent referral to a paediatric hormone specialist or an Endocrinologist.
Girls have a much higher frequency of the condition than boys and the risks of finding any abnormality as a cause are much lower than in boys. However precocious puberty can indicate serious pathology in some girls but is quite infrequent.
What Is The Most Frequent Cause?
Interestingly the family history usually, but not always gives a clue, as one or another parent, or sometimes grandparent may have experienced early puberty. A history of head injury, exposure to drug treatments all need to be assessed. A thorough examination is essential, and this should include the genital area to assess the state of puberty. Often no tests are required, but if they are required they are usually blood tests and an X-ray to see how old a child’s bones are, compared to their biological age.
"Idiopathic" precocious puberty is the commonest cause of precocious or Gonadotrophin Dependant Puberty and is more commonly seen in girls than boys.
In most girls, a specialist review is recommended even if the diagnosis of true precocious puberty (normal but early) is suspected.
There are two other commonly seen conditions in children – called Premature adrenarche and premature thelarche. These are two common, harmless, normal variant conditions that can resemble true precocious puberty but that progress slowly or not at all. Premature thelarche refers to the isolated appearance of breast development, usually in girls younger than 3 years; premature adrenarche refers to the appearance of pubic hair without other signs of puberty in girls or boys younger than 7-8 years. A thorough history, physical examination, and growth curve review can help to distinguish these normal variants from true sexual precocity.
What To Do?
If the history, physical examination, and laboratory data suggest that a child exhibits early and sustained evidence of pubertal maturation then it is important to identify the type of precocious puberty.
Precocious (pseudo) puberty is much less common and refers to conditions in which increased production of sex steroids is gonadotropin-independent. Correct diagnosis of the cause of precocious puberty is essential because the assessment and treatment of patients with precocious pseudo-puberty are quite different from those of patients with true or central precocious puberty.
If you are concerned about your child’s development please contact your GP or a Paediatrician.