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Precocious Puberty

Reviewed by: Steven Dowshen, MD

What Is Puberty?

Puberty is when kids develop physically and emotionally into young men and women. Usually, this starts to happen in adolescence — no earlier than about 7 to 8 years of age in girls (the average age is 10) and 9 years of age for boys (the average age is 11).

What Is Precocious Puberty?

Precocious puberty is when the signs of puberty start before age 7 or 8 in girls and age 9 in boys. It can be physically and emotionally hard for kids and sometimes is a sign of a health problem.

What Are the Signs & Symptoms of Precocious Puberty?

In girls, signs of precocious (prih-KOE-shiss) puberty include any of these before 7 or 8 years of age:

  • breast development
  • pubic or underarm hair development
  • rapid height growth (a growth spurt)
  • start of menstruation (her period)
  • acne
  • "mature" body odor

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

How Does Precocious Puberty Affect Kids?

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 that's not treated usually don't reach 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 also can be hard for kids emotionally and socially. Girls with precocious puberty, for example, may be confused or embarrassed about getting their periods or having enlarged breasts well before any of their peers. But the hardest part may be the teasing that kids with the condition — especially girls — may experience.

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.

What Causes Precocious Puberty?

The onset of puberty is normally triggered by the hypothalamus (the area of the brain that helps control pituitary gland function). It signals the (a pea-sized gland near the base of the brain) to release hormones that stimulate the ovaries (in girls) or testicles (in boys) to make sex hormones.

Sometimes, precocious puberty stems from:

  • a problem in the brain, such as a tumor
  • brain injury due to head trauma
  • an infection, such as meningitis
  • a problem in the ovaries or thyroid gland that triggers the start of puberty ahead of schedule

For most girls with precocious puberty, there's no medical problem at fault. They start puberty too early for no known reason.

In boys, the condition is less common and more likely to be related to another medical problem. And for about 5% of boys, precocious puberty is inherited. Early puberty can be passed:

  • from a father to his son
  • from a maternal grandfather to a grandson through his mother (who will not be affected by it)

What Is "Partial" Precocious Puberty?

Many kids who show early signs of puberty have what's known as "partial" precocious puberty. Some very young girls (usually from 6 months to 3 years old) may show breast development that later disappears or may last without other physical changes of puberty.

Similarly, some girls and boys may have early growth of pubic and/or underarm hair that isn't related to other changes in sexual development.

Kids with "partial" precocious puberty may need to see their doctor to rule out "true" precocious puberty or other health problems. But most need no treatment and will show the other expected signs of puberty at the usual age.

How Is Precocious Puberty Diagnosed?

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
  • pubic or underarm hair

To confirm a diagnosis of precocious puberty, the doctor may order blood and urine tests to look for high levels of sex hormones. X-rays of your child's wrist and hand can show whether the bones are maturing too early.

Imaging and scanning tests such as CT scans, MRIs, and ultrasound studies can help rule out specific causes of precocious puberty, such as a in the brain, ovary, or testicle.

How Is Precocious Puberty Treated?

If your child has precocious puberty, the doctor may refer you to a pediatric (a doctor who specializes in growth and hormonal disorders in children) for treatment.

The treatment goals are to stop or even reverse sexual development and stop the rapid growth and bone maturation that can result in adult short stature.

Depending upon the cause, there are two possible approaches to treatment:

  1. treating the underlying cause or disease, such as a tumor
  2. lowering the high levels of sex hormones with medicine to stop sexual development from continuing

Sometimes, treatment of a related health problem can stop the precocious puberty. But in most cases, no other disease is triggering the condition, so treatment usually involves hormone therapy to stop sexual development.

The currently approved hormone treatment is with drugs called LHRH analogs. These synthetic (manmade) hormones block the body's production of the sex hormones that cause 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 too.

What Can Parents Do?

Give your child a simple, truthful explanation about what's happening. Explain that these changes are normal for older kids and teens, but that his or her body started developing a little too early. Keep your child informed about treatment and what to expect along the way.

Also watch for signs that teasing or other problems may be affecting your child emotionally. Common warning signs to discuss with your doctor include:

  • poor grades
  • problems at school
  • loss of interest in daily activities
  • depression

How parents react can affect how well kids cope. The goal is to prevent kids from dwelling on sexual development or developing a poor self-image or low self-esteem. To create a supportive environment:

  • Avoid making comments about your child's appearance.
  • Offer praise for achievements in school or sports.
  • Support your child's interests in other activities.

The important thing is that precocious puberty can be treated. Doctors can help kids preserve their adult height potential and limit the emotional and social issues they may face from maturing early.

Reviewed by: Steven Dowshen, MD
Date reviewed: June 2015