Puberty is the time of life when a child develops into an adult. It usually begins as early as age 7½ to 8 and as late as age 13 in girls, and between ages 9 and 14 in boys. African American and Hispanic children tend to start puberty about six months earlier than white children.
At puberty, the gonads—ovaries in girls and testes in boys—start to function. Puberty includes these physical changes:
Most children who have “precocious” (early) puberty do not have a health problem. But, they should see a doctor to make sure they do not.
Puberty occurs when a part of the brain called the hypothalamus releases gonadotropin-releasing hormone (GnRH). This hormone stimulates the pituitary gland (a small gland at the base of the brain) to release two other hormones: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH then stimulate the gonads to produce sex hormones—estrogen in girls and testosterone in boys. This leads to the physical changes of puberty.
The adrenal glands (two small glands located above the kidneys) also play a role in producing sex steroids. Their role, though, is usually less important than that of the gonads.
Precocious puberty is the appearance of any sign of secondary sex characteristics in boys younger than age 9 and in girls younger than 7½ or 8. In the United States, precocious puberty affects about 1 to 2 percent of children. Yet, in most of these children, early puberty is a variation of normal, and no medical problem is present.
Many children who go through puberty early or late have other family members who went through puberty early or late. Just as there are differences in the age at which puberty starts, there are also differences in the rate at which a child goes through puberty.
Near the end of puberty, growth in height stops. Because the bones of children with precocious puberty mature and stop growing earlier than normal, these children can be shorter than expected as adults. Precocious puberty can also cause emotional and social problems for children who are ahead of their peers in terms of sexual maturity.
Many forms of precocious puberty are simply variants of normal. For instance, breast development in very young girls and pubic or underarm hair in young children, without other signs of puberty, usually do not signal an underlying medical problem.
Two main types of precocious puberty are abnormal. The first is called central precocious puberty (CPP) and the second is peripheral precocious puberty (PPP).
CPP occurs when the hypothalamus releases GnRH and activates puberty early. In most girls with CPP, there is no underlying medical problem. In boys, the condition is less common and is more likely to have a link to a medical problem. Such problems include a tumor, brain trauma (such as a blow to the head, brain surgery, or radiation treatment to the head), or inflammation (such as meningitis).
PPP is rarer than CPP. It results from early production of sex hormones due to problems with the ovaries, testicles, or adrenal glands. Another cause can be external exposure to sex hormones (such as coming into contact with an estrogen or testosterone cream).
To make a diagnosis, your child’s doctor will take a medical history and perform a physical exam. Blood tests may be done to measure hormone levels. The doctor may order an x-ray of the hand to see if the child’s bones are maturing too fast. Sometimes a CT scan or MRI is ordered to check for a tumor.
Rarely, blood might be sent to a lab to look for a change in a gene (genetic mutation) that could result in an uncommon type of precocious puberty.
If your child has any sign of precocious puberty, visit a pediatric endocrinologist. This doctor is an expert in the treatment of hormone-related conditions in children. Precocious puberty requires tests to ensure there is no underlying medical cause. Your doctor will work with you to decide the best treatment option.
If your child has CPP, there are medications to prevent further pubertal development. If the problem is PPP, the treatment will depend on the underlying cause. It could involve medications, surgery (if there is a tumor), or removing the external source of the hormones (such as estrogen cream).