Early puberty in boys
Puberty occurs when physical changes transform a child into an adult capable of producing a baby. Some boys go through puberty at a young age: this is called precocious puberty.
What happens during puberty?
The pituitary gland at the base of the brain is responsible for producing gonadotrophins: these are the luteinising hormone and follicle-stimulating hormone.
At birth, their levels are high, but they decrease within a few months and remain low until the onset of puberty. When the levels of these two hormones increase at the start of puberty, they trigger the production of the sex hormones in the testes ( testicles) in boys. One of them is testosterone, which is responsible for stimulating physical changes in boys as they reach sexual maturity.
What are the signs of puberty in boys?
It may not be obvious, but the first sign of puberty in boys is the enlargement of the testicles; then in a few months the penis will also grow and pubic hair will appear.
Boys may have 'wet dreams' (uncontrolled ejaculations of semen as they sleep), and their voice will break, with the pitch and tone becoming lower. Facial hair will appear later, at about 15 years. The growth spurt in boys starts later than in girls, normally at about 14, and adult height will not be reached until about 17 years or later.
What is considered early, or precocious, puberty in boys?
Puberty usually takes six years and typically occurs between the ages of nine and 15 in boys, with the first signs in boys appearing at about 12 years. If there are signs of puberty before nine years in boys, it is considered to be early, or precocious, puberty.
Early puberty is more common in boys than girls.
Occasionally, only one area of the maturing process of puberty begins on its own. If there is only body hair or pubic hair development, it is known as premature adrenarche or pubarche. This condition occurs more often than true central early puberty, and there is a difference between how they are managed.
What problems are associated with early puberty in boys?
Early puberty has been associated with behavioural and emotional difficulties such as social integration and the ability to concentrate at school.
Because the children will have accelerated growth spurt early on, they will stop growing early on and may be short as adults, or they may have weak bones.
What are the causes of early puberty in boys?
An underlying medical condition is normally associated with early puberty in boys, so medical investigation is important.
The GPR54 gene usually triggers a chain reaction that begins in the brain and is responsible for starting the release of hormones to begin puberty. Possible causes for the gene being triggered early include:
- Head trauma causing injury to the brain
- A brain tumour
- An infection in the brain such as meningitis
- A thyroid gland problem
- A problem in the testes