There is a wide range of ages at which young children undergo the
physical changes that normally occur during puberty. In most cases it is
safe to predict that girls will begin to develop breasts and then pubic hair
between the ages of 8 and 13. Menstrual periods typically start
at 12 to 13 years of age. Boys normally develop testicular enlargement and
then pubic hair between the ages of 9 and 14 years.
Puberty is said to be precocious (very early) if it begins before
age 6-7 in girls and 9.5 in boys. Precocious puberty is five
to seven times more likely in girls than boys and occurs in one out of every
5,000 to 10,000 American children.
The changes of puberty are triggered by the pituitary gland, a pea-sized
structure at the base of the brain and under the influence of the hypothalamus
gland. Before puberty begins, higher brain functions prevent the hypothalamus
from allowing the pituitary gland to begin secreting hormones. Precocious
puberty most likely results when this "restraint" is removed ahead of schedule,
allowing the pituitary gland to begin secreting gonadotropins, which in turn
stimulate the ovaries or testes to produce sex hormones. These sex hormones
(especially estrogen in girls and testosterone in boys) are what normally
cause sexual maturity to begin. The hormonal changes of precious puberty
are normal, but it is just that the whole process begins a few years too
soon.
Signs that a child may have precocious puberty are the development
of secondary sex characteristics——breasts, pubic hair and menstruation
in girls, and pubic hair, an enlarged penis and testicles, facial hair and
vocal deepening in boys. In addition, children undergoing precocious puberty
enter a period of rapid growth and weight gain similar to that of normal
adolescence when the bones harden and mature.
In most cases, no reason can be found to explain why the pituitary
gland signaled the ovaries and testicles to prematurely make female or male
hormones. Sometimes, precocious puberty is caused by an abnormality in the
ovaries, testicles or adrenal glands, and rarely, it is due to a
hormone-secreting tumor in the pituitary or hypothalamus. Therefore, any
girl who shows signs of sexual maturation before age 6 - 7 (and any boy who
begins to mature before age 9.5) should definitely see their
doctor. Often the child with precocious puberty is referred to a pediatric
endocrinologist, a specialist who treats children with hormone and growth
problems. Blood and urine tests are then performed to uncover the presence
of elevated sex hormones levels. X rays, particularly of the wrist and hand,
can show whether the bones are growing too fast. Tests to determine whether
the problem involves the pituitary, hypothalamus or both may be necessary.
Special imaging tests (CT or MRI scans) might also be performed to detect
tumors in the pituitary, hypothalamus, liver, ovary or testes.
Children with very early puberty tend to be tall for their age when
they start growing but they stop growing earlier than other young people.
Therefore, they may be quite short in height when they are adults. Normal
early puberty does not have to be treated. True precocious puberty may need
treatment.
In addition, children with precocious puberty look different from
their peers, causing them to be self-conscious and embarrassed about their
bodies. Adults often expect them to act more maturely simply because they
look so much older. As a result, many of these children--especially boys--are
much more aggressive than others their own age, leading to behavior problems.
Treatment for precocious puberty depends on its cause. It may involve
surgery and radiation if the cause is a hormone-secreting tumor. In addition,
new medication can reverse some of the signs of precocious puberty. Parents
should therefore call their child's doctor if there are any signs of early
sexual development or the pre-adolescent seems to be growing and gaining
weight too quickly.
For information about premature breast development, see Premature Thelarche
For information about premature development of pubic hair, see Premature Adrenarche
