Early hair growth, odor isn’t always a sign of early puberty

The development of adult body odor and axillary hair growth early in life may not always signal that a child is beginning puberty.

Premature adrenarche may be more outwardly obvious than other early cues to puberty, but it doesn’t necessarily signal the start of sexual maturity.

Adrenarche occurs when the adrenal androgens—sex hormones—that trigger pubic and axillary hair growth, body odor, and acne are produced. These androgens alone don’t signal the start of puberty. Instead, this process is measured by the appearance of breast tissue in girls and testicular growth in boys.

The signs of premature, or early, adrenarche don’t typically occur alongside growth spurts unless they appear in rare cases of central precocious puberty—an early entry to the entire process of sexual maturation.

Katherine Kutney, MD, a pediatric endocrinologist at Rainbow Babies and Children’s Hospital in Cleveland, Ohio, said puberty is considered premature in girls younger than age 8 years and boys younger than age 9 years.1 Timing of premature adrenarche can coincide with central puberty, but this isn’t always the case. In some cases, premature adrenarche may occur simply as a difference in timing and development. However, a specialist can help determine whether there may be a differential diagnosis to consider.

“The main differential for premature adrenarche includes benign premature adrenarche, congenital adrenal hyperplasia, functional adrenal tumor, and exogenous testosterone exposure,” Kutney stated. “Penis or clitoral enlargement, growth acceleration, or very rapid progression are more concerning for pathologic causes.”

Some diagnostic tools that Kutney explained may be used to help confirm or rule out alternative diagnoses include blood tests for:

  1. 17-OH levels to check for congenital adrenal hyperplasia (CAH)
  2. Dehydroepiandrosterone sulfate blood test to measure adrenal gland function
  3. Androstenedione to assess for CAH and measure adrenal function
  4. Testosterone to rule out hormone-secreting adrenal tumors

It can also be helpful to use an X-ray to check bone age alongside blood tests.

“If bone age is advanced more than 2 years, or hormone levels are elevated for the stage of puberty, this suggests possibility of a pathologic cause,” Kutney explained.

If all of these tests come back normal—or normal for the Tanner stage of the child—a diagnosis of premature adrenarche alone is usually appropriate, she added. Children who have premature adrenarche should see a pediatric endocrinologist, Kutney said, but this step is particular important for any children who also have criteria that is suggestive of a differential diagnosis.

Even without a pathological process at play, research shows that premature adrenarche has been linked to a number of long-lasting metabolic issues like2,3:

  1. Hyperinsulinism
  2. Insulin resistance
  3. Dyslipidemia
  4. Late-appearing ovarian hyperandrogenism
  5. Obesity
  6. Increased height growth during puberty

Few studies have followed cohorts long enough to tell if these issues continue into adulthood in children who face premature adrenarche. A few reports, however, have found that girls who had premature adrenarche remained taller, weighed more, and reached menarche earlier than their peers by age 12 years. Height differences don’t appear to permanent, though, with most girls who had premature adrenarche reaching an average height by adulthood regardless of their pubescent growth rates.3

References

1. Kaplowitz P, Bloch C. Evaluation and referral of children with signs of early puberty.Pediatrics. January 2016;137(1). doi: 10.1542/peds.2015-3732.

2. Utriainen P, Laakso S, Liimatta J, Jääskeläinen J, Voutilainen R. Premature adrenarche - a common condition with variable presentation. Horm Res Paediatr. 2015;83:221-231. doi: 10.1159/000369458

3. Liimatta J, Utriainen P, Voutilainen R, Jääskeläinen J. girls with a history of premature adrenarche have advanced growth and pubertal development at the age of 12 years. Front Endocrinol (Lausanne). 2017;8.291 doi:10.3389/fendo.2017.00291