Sexual development before the age of eight in girls, and age 10 in boys is considered precocious puberty. Not every child reaches puberty at the same time, but in most cases it's safe to predict that sexual development will begin at about age 11 in girls and 12 or 13 in boys. However, occasionally a child begins to develop sexually much earlier. Between four to eight times more common in girls than boys, precocious puberty occurs in one out of every 5,000 to10,000 American children.
Precocious puberty often begins before age 8 in girls, triggering the development of breasts and hair under the arms and in the genital region. The onsetof ovulation and menstruation also may occur. In boys, the condition triggersthe development of a large penis and testicles, with spontaneous erections and the production of sperm. Hair grows on the face, under arms and in the pubic area, and acne may become a problem.
While the early onset of puberty may seem fairly benign, in fact it can causeproblems when hormones trigger changes in the growth pattern, essentially halting growth before the child has reached normal adult height. Girls may never grow above 5 ft (152 cm) and boys often stop growing by about 5 ft 2 in (157 cm).
The abnormal growth patterns are not the only problem, however. Children withthis condition look noticeably different than their peers, and may feel rejected by their friends and socially isolated. Adults may expect these childrento act more maturely simply because they look so much older. As a result, many of these children--especially boys--are noticeably more aggressive than others their own age, leading to behavior problems both at home and at school.
Puberty begins when the brain secretes a hormone that triggers the pituitarygland to release gonadotropins, which in turn stimulate the ovaries or testesto produce sex hormones. These sex hormones (especially estrogen in girls and testosterone in boys) cause the onset of sexual maturity.
The hormonal changes of precocious puberty are normal--it's just that the whole process begins a few years too soon. Especially in girls, there is not usually any underlying problem that causes the process to begin too soon. (However, some boys do inherit the condition; the responsible gene may be passed directly from father to son, or inherited indirectly from the maternal grandfather through the mother, who does not begin early puberty herself). This genetic condition in girls can be traced only in about 1% of cases.
In about 15% of cases, there is an underlying cause for the precocious puberty, and it is important to search for these causes. The condition may result from a benign tumor in the part of the brain that releases hormones. Less commonly, it may be caused by other types of brain tumors, central nervous systemdisorders or adrenal gland problems.
Physical exams can reveal the development of sexual characteristics in a young child. Bone x-rays can reveal bone age, and pelvic ultrasound may show an enlarged uterus and rule out ovarian or adrenal tumors. Blood tests can highlight higher-than-normal levels of hormones. MRI or CAT scans should be considered to rule out intracranial tumors.
Treatment aims to halt or reverse sexual development so as to stop the accompanying rapid growth that will limit a child's height. There are two possibleapproaches: either treat the underlying condition (such as an ovarian or intracranial tumor) or change the hormonal balance to stop sexual development. Itmay not be possible to treat the underlying condition; for this reason, treatment is usually aimed at adjusting hormone levels.
There are several drugs which have been developed to do this including: histrelin (Supprelin), nafarelin (Synarel), synthetic gonadotropin-releasing hormone agonist, deslorelin, ethylamide, triptorelin, and leuprolide.
Drug treatments can slow growth to 2-3 in (5-7.5 cm) a year, allowing these children to reach normal adult height, although the long-term effects aren't known.