Precocious Puberty

Puberty is the time in life when the body changes from that of a child to an adult. It includes rapid growth of bones and muscles, changes in body shape and size, and development of your body's ability to reproduce. Puberty normally takes place in girls between ages 8 and 16 and in boys between ages 9 and 14. Precocious puberty — the onset of signs of puberty before age 7 or 8 in girls and age 9 in boys — can be physically and emotionally difficult for kids and can sometimes be the sign of an underlying health problem.

In girls, the signs of precocious puberty include any of the following before 7 or 8 years of age:

  • breast development
  • pubic or underarm hair development
  • rapid height growth — a growth "spurt"
  • onset of menstruation
  • acne
  • "mature" body odor

In boys, the signs of precocious puberty before 9 years of age include:

  • enlargement of the testicles or penis
  • pubic, underarm, or facial hair development
  • rapid height growth — a growth "spurt"
  • voice deepening
  • acne
  • "mature" body odor

When puberty ends, growth in height stops. Because their skeletons mature and bone growth stops at an earlier age than normal, kids with precocious puberty usually don't achieve their full adult height potential. Their early growth spurt may make them initially tall when compared with their peers, but they may stop growing too soon and end up at a shorter height than they would have otherwise. Going through puberty early can also be difficult for a child emotionally and socially. For example, girls with precocious puberty may be confused or embarrassed about physical changes such as getting their periods or having enlarged breasts well before any of their peers. Even emotions and behavior may change in kids with precocious puberty. Girls can become moody and irritable. Boys can become more aggressive and also develop a sex drive inappropriate for their age.

The onset of puberty is normally triggered by the hypothalamus (the area of the brain that helps control pituitary gland function). It signals the pituitary gland (a pea-sized gland near the base of the brain) to release hormones that stimulate the gonads (ovaries in girls, testicles in boys) to make sex hormones. Precocious puberty is broken down into two main types – Central and Peripheral – based on the cause for puberty starting early.

In central precocious puberty, the entire Hypothalamus-Pituitary-Gonad axis simply starts too soon. Although the process begins earlier than it should, the pattern and timing of the steps in the process are normal. For the majority of children with this condition, there's no underlying medical problem and no reason that can be identified for the progression of puberty to begin when it did.
In rare cases, the cause may be due to:

  • A tumor in the brain or spinal cord
  • An infection, such as encephalitis or meningitis
  • A defect in the brain present at birth, such as excess fluid build-up or a noncancerous tumor
  • Radiation to the brain or spinal cord
  • Injury to the brain or spinal cord
  • An obstruction of blood flow to the brain
  • McCune-Albright syndrome
  • Congenital adrenal hyperplasia
  • Hypothyroidism

In peripheral precocious puberty – which is less common than central – there is an increase in estrogen or testosterone not triggered by the hypothalamus. This type of puberty may appear to be incomplete with some areas of the body developing while others remain age appropriate. The improper increase in sex hormones is usually caused by a problem in the ovaries, testicles, adrenal glands, or pituitary gland. This may be due to:

  • A tumor in the adrenal glands or pituitary gland that secretes estrogen or testosterone
  • McCune-Albright syndrome
  • Exposure to external sources of estrogen or testosterone such as creams or ointments
  • Ovarian cysts or tumors [in girls]
  • Tumor in the cells that make sperm (germ cells) or the cells that make testosterone (Leydig cells) in boys
  • A rare inherited disorder, which is usually found in boys of toddler age, called familial gonadotropin-independent sexual precocity

Talk to your doctor if your child shows any signs of early sexual maturation before age 7 or 8 in girls or age 9 in boys, including breast development, rapid height growth, menstruation, acne, enlarged testicles or penis, or pubic or underarm hair. The physical changes boys and girls go through during puberty are usually evident to a doctor during an exam. To confirm a diagnosis of precocious puberty, the doctor may order blood and urine tests to detect elevated levels of sex hormones. And X-rays of your child's wrist and hand can show whether the bones are maturing too rapidly. Imaging and scanning tests such as CT scans, MRIs (magnetic resonance imaging), and ultrasound studies can help rule out specific causes of precocious puberty, such as a tumor in the brain, ovary, or testicle.

Once precocious puberty is diagnosed, the goal of treatment is to halt or even reverse sexual development and stop the rapid growth and bone maturation that can eventually result in adult short stature. Depending upon the cause, there are two possible approaches to treatment:

  • treating the underlying cause or disease, such as a tumor
  • lowering the high levels of sex hormones with medication to stop sexual development from progressing

In some cases, treatment of an underlying health problem can stop the precocious puberty from progressing. But in most cases, because there is no other disease triggering the condition, treatment usually consists of hormone therapy that stops sexual development. The currently approved hormone treatment is with drugs called LHRH analogs — synthetic hormones that block the body's production of the sex hormones that are causing the early puberty. Dramatic results are usually seen within a year of starting treatment with an LHRH analog, which is generally safe and usually causes no side effects in kids. In girls, breast size may decrease — or at least there will be no further development. In boys, the penis and testicles may shrink back to the size expected for their age. Growth in height will also slow down to a rate expected for kids before puberty. A child's behavior usually becomes more age appropriate as well.

Useful Links:

Precocious Puberty Support Group
(http://dailystrength.org/c/Precocious-Puberty/support-group)

The MAGIC Foundation – Precocious Puberty
(http://www.magicfoundation.org/www/docs/146/)

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