When is puberty too early?

In the past 10 years, parents increasingly ask me whether their child’s maturing to puberty is occurring at too early an age. Often, girls in fourth grade seem to be maturing, and their parents are not ready for it.

Deanna Adkins, MD, a pediatric endocrinologist, discusses the normal progression of puberty and explains warning signs that indicate puberty is happening too early.

-- Dennis Clements MD, PhD, MPH

As any parent who has been to his child’s classroom or sporting activity knows, kids come in all sizes.

These size differences get pronounced when puberty arrives in some of the children and not others.

One of the more noticeable things that occur is that girls shoot up past the boys around 11 or 12 years of age. Then the boys catch up and pass them by around 14 or so.

This is the usual pattern, but many children follow their own pattern that can be very different from this.

Early and late bloomers are considered different from the normal pattern of puberty, but these patterns occur frequently in adolescents and should be considered a variant of normal. Both tend to run in the family with both boys and girls going into puberty a little later or earlier than their peers.

When should a parent worry?

What Is early or precocious puberty?

As previously mentioned, the first signs of puberty are expected at very different times in boys and girls. There has been much study and discussion in the medical community about the early onset of puberty in and when it should be evaluated.

The focus has traditionally been on girls, but recently there has been some evidence and discussion surrounding this in boys as well.

Early puberty in girls

For girls, puberty is generally considered to be too early if it begins at age seven or eight. African-American and Hispanic girls tend to start puberty slightly earlier than Caucasian girls.

The average age of pubertal onset in girls is 10-and-a-half years old, but it ranges from seven to 13 years old. The average age of menarche is 12-and-a-half to 13 years of age. The whole process of puberty should take three to four years.

Rapidly progressing puberty -- start to finish in less than two years -- can be a concern as well because it can be due to an endocrine disorder.

The first sign of puberty in girls is most often breast development. Other signs include:

  • Body odor
  • Pubic hair
  • Acne
  • Growth spurt
  • Menses (rarely)

Early puberty in boys

For boys, puberty is generally considered too early before the age of nine years.  In boys, onset of puberty is from nine to 14 years, but on average starts at 11-and-a-half to 12 years old.

The whole process of puberty should take three to four years. Rapidly progressing puberty can also be a concern in males.

The first sign of puberty in boys is usually testicular growth. Other signs include:

  • Body odor
  • Pubic hair
  • Penile growth
  • Acne
  • Axillary hair
  • Facial hair
  • Growth spurt
  • Deepening of the voice

If Your child shows signs of early puberty

If any of these signs occur in girls before age seven or eight or in boys before age nine, an evaluation should be considered.

Often, the first step is an x-ray of the hand and wrist called a bone age test to see if these hormones have affected the growth and bone maturity of the child already. Further evaluation can include blood tests, ultrasound, or MRI.

Causes of early puberty

In almost 90 percent of the cases of early puberty in girls, there is no known cause. In the other 10 percent, possible causes could be an abnormal brain structure or tumor, ovarian cysts (including McCune Albright syndrome), deficient thyroid function (hypothyroidism), head trauma, radiation, adrenal hyperplasia or tumor, or exposure to environmental hormones or hormone-like chemicals.

In boys, the onset of early puberty is more likely to be caused by an underlying disease.

Diseases that cause early puberty include structural abnormalities of the brain; radiation; tumors of the brain, testis, liver, and adrenal gland; inherited disorders such as adrenal hyperplasia or testotoxicosis; exposure to hormones or hormone-like compounds in the environment, or hypothyroidism.

Possible other causes of early puberty that are currently being studied include environmental chemicals and obesity.

Risk factors for developing early puberty

Risk factors often linked to early puberty in children include:

  • Being a female
  • Obesity
  • African-Americans and Hispanics
  • Exposure to hormones from medications or environment
  • Head injury including radiation and surgery
  • Other medical conditions such as congenital adrenal hyperplasia, McCune Albright syndrome, neurofibromatosis, and hypothyroidism

Treatments for early puberty

The first step is to treat the cause of early puberty. This may include surgery to remove the tumor or medications to replace the thyroid.

To stop or slow down the puberty, medication is often used to regulate testosterone or estrogen production; these medications are known as LHRH analogs or antagonists. They are available in several forms that include a monthly injection, quarterly injection, subcutaneous implant, and, rarely, a nasal spray.

For certain forms of early puberty, other medications are used. These block estrogen production from male hormones (androgens) or block the estrogen receptor itself.

One of the complications of early puberty is early closing of the growth plates that leads to short stature. If there is evidence that this is occurring, growth hormone can be added to the treatments above to optimize final adult height.

In addition to the physical changes in early puberty, there are also psychological concerns that may need to be addressed.

This may require a referral to a counselor as puberty can be a difficult transition at the normal age of onset and can be very difficult in a young child who may have more difficulty understanding the changes going on in their bodies. These children are at risk for low self-esteem, depression, and substance abuse.

Preventing early puberty

While genetic factors play a role in the early onset of puberty, parents can help delay the environmental causes of early puberty. Preventive measures include:

  • Encourage your child to maintain a healthy weight.
  • Avoid exposure to exogenous hormones like estrogen, testosterone, DHEA, androstenedione that may be found in creams/gels, hair treatments, medications, and nutritional supplements.

-- Deanna Adkins, MD, is a pediatric endocrinologist with Duke Department of Pediatric's Division of Endocrinology.

-- Dennis Clements, MD, PhD, MPH, is the chief of primary care pediatrics at Duke Children's Hospital.

Written by Staff for Duke Medicine    |    Added February 6, 2014