One of the problems with starting puberty at an earlier age is that puberty also triggers a period of rapid growth and weight gain that stops when puberty ends. Because bone growth stops at an earlier age than normal, children with precocious puberty usually do not achieve their potential full adult height. Although they may at first seem tall compared to their classmates, they will stop growing too soon and end up at a shorter height than normal. If untreated, boys typically grow no taller than 5 feet, 4 inches and girls rarely reach 5 feet.
Reaching puberty too early also can be emotionally and socially difficult, because very young children often are not emotionally equipped to undergo the physical changes.
The onset of puberty is normally triggered by the pituitary gland. Precocious puberty may be caused by a structural problem in the brain, or a problem in the 0varies. However, in most girls, there is no underlying visible medical problem that experts can discover.
When the condition appears in boys, it may be caused by head trauma or a hormone-producing tumor in the pituitary gland or hypothalamus. The condition also may appear along with a condition such as Down’s syndrome or untreated hypothyroidism. The condition is inherited in about five percent of boys. Precocious puberty early can be passed from father to son or from the maternal grandfather through the mother (who will be unaffected) to the son. Less than one percent of girls affected by precocious puberty have inherited the condition.
Some children develop precocious puberty as a result of exposure to estrogen in drugs or food (called “medicational precocity”). This consists primarily of breast development. Children can be exposed to estrogen if they swallow estrogen-replacement medication or birth control pills. Occasionally, reports suggest that estrogen given to livestock also can cause breast development in children.
The most obvious signs of the onset of precocious puberty are the development of secondary sex characteristics. In girls, the signs of precocious puberty include any of the following signs appearing before age 7:
• breast development
• pubic or underarm hair development
• onset of menstruation
• body odor
• moody and irritable behavior
In boys the signs of precocious puberty include any of the following signs before age nine:
• enlargement of the test!cles or pen!s
• pubic, underarm, or facial hair development
• deepening voice
• body odor
• inappropriate sex drive
Partial Precocious Puberty
Many children with early signs of puberty are actually experiencing “partial” precocious puberty. Some girls, usually beginning between the ages of six months and three years, may experience breast development that later disappears, or that may remain without other physical changes of puberty. Other girls and boys may experience early growth of pubic or underarm hair without any other changes in sexual development.
Children with partial precocious puberty may require evaluation to rule out true precocious puberty, but they generally need no treatment and usually will show the other expected signs of puberty at the usual age.
The physical changes of puberty are usually obvious to a doctor during a routine physical exam. To confirm a diagnosis of precocious puberty, a child’s doctor may order blood and urine tests to detect high levels of sex hormones. X rays of the wrist and hand can reveal whether the bones are maturing too rapidly. Imaging and scanning tests such as computerized tomography (CT) scans and magnetic resonance imaging (MRI) can help rule out specific causes of precocious puberty, such as a tumor in the pituitary gland, hypothalamus, brain, 0vary, or test!cle.
The goal of treating precocious puberty is to halt or reverse sexual development and stop the rapid growth and bone maturation that will eventually result in adult short stature. This can be done either by treating the underlying cause of disease (such as a tumor) or normalizing hormone levels with medication to stop sexual development from progressing. Often a tumor cannot be removed, but even when removal is possible, this rarely stops precocious puberty from continuing. Treating an underactive thyroid condition with medication may be effective.
In most cases there is no underlying disease triggering the precocious puberty, so treatment usually consists of hormone therapy to stop sexual development. The currently approved hormone treatment involves synthetic drugs called LHRH analogs, which reduce the secretion of sex hormones within two weeks of administration; symptoms begin to disappear soon after this.
Dramatic results are usually seen within a year of starting treatment with an LHRH analog. In girls, breast size may decrease and pubic hair may fall out, or there will be no further development. In boys, the pen!s and test!cles may shrink and pubic and facial hair may decrease. A child’s behavior usually becomes more age-appropriate as well.