Precocious puberty

Typically, puberty begins around age 10 in girls, and age 12 for boys. But in precocious puberty, the puberty begins early — before age 8 in girls and before age 9 in boys. Although early puberty is often a variant of normal development, it can sometimes be a sign of an underlying health problem, so it is important for the child to see a pediatric endocrinologist.

Although it is not always worrisome, there are some consequences of precocious puberty to be aware of. Because of its early onset, the bone maturation process — which is triggered by some of the same hormones that start puberty — ends earlier as well. So, children with early puberty may be tall for their age at the time of puberty but will mature into short adults.

Other risks include emotional problems brought on by the difficulties of growing up different than one’s peers. Finally, early puberty may, at times, be initiated by processes which require treatment to prevent other ill effects.

Signs of precocious puberty

In both boys and girls:

Acne
Adult body odor
Pubic, leg or underarm hair growth
Rapid growth in height

In girls:

Breast development
Onset of menstruation

In boys:

Enlargement of the testicles or penis
Facial hair development
Voice changes

Causes of precocious puberty

First, it is important to understand what triggers typical puberty. Puberty is triggered by the secretion of a hormone called gonadotropin-releasing hormone. Gonadotropin-releasing hormone is produced by the hypothalamus, a part of the brain that secretes various other hormones that stimulate the pituitary gland. When stimulated by hypothalamic gonadotropin-releasing hormone, the pituitary gland in turn releases the gonadotropins which then stimulate the production of sex hormones in the gonads (ovaries and testicles). The adrenal glands also produce some of the same hormones.

This process can begin early for a variety of reasons:

Some kind of structural problem in the brain (such as abnormal growths or masses)
Brain injury due to head trauma
An infection (such as meningitis or encephalitis)
A problem in the ovaries, testes or thyroid gland
Overweight in girls

For the majority of girls, there is no underlying medical problem; they simply start puberty too early for no known reason. In boys, the condition is less common, and more likely to be associated with an underlying medical problem than it is in girls.

Types of precocious puberty

Incomplete precocious puberty is often a variant of normal development. Thus, boys or girls may experience only early appearance of pubic hair or girls may experience only early breast development. These incomplete forms do not ordinarily require specific treatment.
Gonadotropin-dependent precocious puberty, also known as central precocious puberty, is less common than the incomplete forms and affects many more girls than boys.
Gonadotropin-independent precocious puberty is not related to the early release of hormones from the hypothalamus and pituitary, but reflects spontaneous hormone production by the gonads (ovaries or testes.)

How precocious puberty is diagnosed

While precocious puberty can be upsetting to children and parents alike, it doesn’t always require treatment. It all depends on the underlying cause, which is why a thorough work-up by a pediatric endocrinologist is important.

In addition to a complete medical history and physical examination, tests to refine the diagnosis may include:

An x-ray of the hand and wrist to determine if the growth centers of the bone are closer to closing than they should be at the child’s age (“bone age” has advanced)
Blood tests to measure hormone levels
An ultrasound of the adrenal glands and the ovaries or testes
An MRI to take detailed images of structures within the body or brain
Hormone stimulation blood tests to determine the form of precocious puberty

Treatment for precocious puberty

The goal of treatment is to slow, and possibly reverse, the onset of early puberty symptoms.

If it is determined that an underlying condition is causing early puberty, the puberty can be arrested by treating the primary condition. However, if precocious puberty is the primary condition, medicines that block the activation of gonadotropin secretion by the pituitary gland include leuprolide (Lupron®) and histrelin (Supprelin®).

The kind of treatment will depend on the cause and on factors such as:

The child's age, overall health, and medical history
The extent of the condition
The child’s ability to tolerate certain medications, procedures or therapies as mentioned above
If necessary, counseling to help the child cope with the emotional affects of early puberty

To make an appointment to see an endocrinologist, call 1.800.KIDS DOC.