Premature Adrenarche

Introduction

Adrenarche is a lot like puberty; it’s characterized by changes in the body as the child enters teen years. Premature adrenarche is when these changes begin early, before age 8 for girls and age 9 for boys. It’s usually nothing serious, simply a child’s body maturing in its own time.

It may be helpful to think of puberty and adrenarche as separate processes that child’s body goes through, usually at the same time, but not always.

  • Adrenarche means “the awakening of the adrenal gland.” The adrenal gland is responsible for making hormones including androgens—sex hormones that cause changes such as the development of pubic hair, oily skin, oily hair and body odor. There is one adrenal gland on top of each kidney.
  • Puberty is the name given to the stage of life at which the body becomes capable of sexual reproduction. During puberty, the brain sends signals to glands in the testes for boys and ovaries for girls, spurring the development of sperm, eggs and other secondary sexual characteristics (such as breasts for girls and a deepening voice for boys).

Associated Anatomy

Adrenarche is an early stage in sexual maturation that happens in some higher primates and in humans typically peaks at around 10 to 14 years of age and is eventually involved in the development of pubic hair, body odor, skin oiliness, and acne.

During adrenarche the adrenal glands secrete increased levels of weak adrenal androgens, including dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), and androstenedione (A4), but without increased cortisol levels. Adrenarche is the result of the development of a new zone of the adrenal cortex, the zona reticularis. Adrenarche is a process related to puberty, but distinct from hypothalamic–pituitary–gonadal axis (HPG axis) maturation and function.

Causes

Premature adrenarche is caused when the adrenal gland begins secreting sex hormones called androgens earlier than normal. In most cases, it’s not that more androgen is being made, it’s that the standard amount is being made earlier than normal. That means that in most cases, the effects of adrenarche are not exaggerated (a child won’t be hairier than her peers), the effects simply appear sooner.

It’s not known what causes the adrenal gland to begin secreting androgens early. Since exposure to these hormones causes premature adrenarche, a child may also experience it if she comes in contact with hormone creams or other hormonal medications.

Differential Diagnosis

Differential diagnosis should be made with following conditions:

Exogenous androgens

Exposure to exogenous sex hormones is an occasional cause of early puberty (eg, pubic hair, phallic enlargement). The most common etiology in young children has been inadvertent exposure to androgens through contact with adult males who use topical androgens such as Androgel. Asking about such potential exposure is important because the problem resolves rapidly when such exposure ceases.

Premature thelarche

Premature thelarche is the appearance of breast development in young girls in the absence of other signs of precocious puberty (eg, growth acceleration, changes in uterine size and vaginal mucosa). Premature thelarche is typically seen in girls aged 3 years or younger. Breast tissue normally seen in the newborn period due to maternal estrogens can persist for a year or more in some infants. The keys to making this diagnosis include the following:

  • Observing that the child is growing in length along her established percentile channel
  • Noting that the amount of breast tissue increases only minimally over time (or may even decrease)
  • Observing a lack of thickening and pigmentation of the nipples and the areola as seen in girls with precocious puberty

 

Drugs

Premature adrenarche doesn’t require treatment with any drugs.

Epidemiology

Recent data suggest that girls seen by primary care practitioners in the United States show pubic hair and/or breast development at younger ages than stated above. In a cross-sectional study involving 17,077 girls, striking differences were detected in pubic hair development between black and white girls. At 6 years of age, 9.5% and, at 8 years of age, 34.3% of black girls had at least Tanner stage 2 pubic hair, whereas 1.4% and 7.7% of white girls, at these ages, had pubic hair.

In Finland, the prevalence of premature adrenarche (PA) is 8.6% in girls and 1.8% in boys

Natural Progression

In general, no health problems are directly caused by premature adrenarche. Girls with premature adrenarche may have periods a few months earlier than they would have otherwise. Some girls with premature adrenarche seem to have an increased risk of developing a disorder called polycystic ovary syndrome (PCOS) in their teenaged years. The signs of PCOS include irregular or absent periods and increased facial, chest, and abdominal hair growth. For all children with premature adrenarche, healthy lifestyle choices are beneficial. Healthy food choices and regular exercise might decrease the risk of developing PCOS.

Pathophysiology

Generally, premature adrenarche is secondary to an early isolated maturation of the adrenal gland. Adrenal androgens, particularly DHEA, DHEAS, androstenedione, and testosterone, are in most cases moderately increased for chronological age but fall within the expected range according to the pubertal stage of pubic hair. In some patients, the early development of pubic hair is associated with normal androgen levels for chronological age, suggesting increased peripheral sensitivity. Lee et al. (150) described a family in whom adrenal androgen hypersecretion was transmitted as a dominant non-HLA-linked trait.

The cause of the adrenal oversecretion in premature adrenarche is currently unclear. Gonadotropins do not play a role in the development of premature adrenarche just as in normal adrenarche.

Possible Complications

In several studies, premature adrenarche has been linked to unfavorable metabolic features including obesity and hyperinsulinism or insulin resistance. Low birth weight or being born small for gestational age (SGA) has been associated with PA in retrospective studies from Australia, Brazil, and Spain. Advanced prepubertal growth in height has been reported in most premature adrenarche cohort studies. One possible link between accelerated statural growth and premature adrenarche is insulin-like growth factor 1 (IGF-1) whose increased concentrations have been found in premature adrenarche children.

Possible Treatment

There is no treatment that will cause the pubic and/or underarm hair to disappear. Medications that slow down the progression of true precocious puberty have no effect on the adrenal hormones made in children with premature adrenarche. Deodorants are helpful for controlling body odor and are safe. If axillary hair is bothersome, it may be trimmed with a small scissors.

Signs or Symptoms

In typical or isolated premature adrenarche the appearance of pubic hair, which is usually dark, straight or curly, and coarse, is mostly limited to the labia majora in girls and thus may elude detection on casual examination in an obese girl. The development of pubic hair is non- to slowly progressive and may spread throughout the pubic area. Axillary hair growth may also be noted. A mild hypertrichosis with fine hair over the extremities and back is much less frequently observed. Increased body odor, oily skin, and acne, usually in the form of a few microcomedones, may be present. Clitoral or penile enlargement are usually absent, and testicular and breast size remain at the prepubertal stage . Growth velocity may be increased, and moderately advanced bone maturation.

Active Not Recruiting

Number of studies: 26

Link

Completed

Number of studies: 0

Link

Enrolling by Invitation

Number of studies: 0

Link

Not Yet Recruiting

Number of studies: 0

Link

Recruiting

Number of studies: 1

Link

Results Available

Number of studies: 0

Link

Results Not available

Number of studies: 0

Link

Suspended

Number of studies: 0

Link

Terminated

Number of studies: 0

Link

Withdrawn

Number of studies: 0

Link

Typical Test

Pediatric endocrinologists may differ in whether to obtain testing when evaluating a child with early pubic hair development. Blood work and/or a hand radiograph to determine bone age may be obtained. For some children, especially taller and heavier ones, the bone age radiograph will be advanced by 2 or more years. The advanced bone development does not seem to indicate a more serious problem that requires extensive testing or treatment. If a child has the typical features of premature adrenarche noted previously and is not growing too rapidly, generally, no medical intervention is needed. Generally, the only abnormal blood test is an increase in the level of dehydroepiandrosterone sulfate (also called DHEA-S), the major circulating adrenal androgen. Many doctors only test children who, in addition to pubic hair, have very rapid growth and/or enlargement of the genitals or breast development.

References:

https://www.pedsendo.org/assets/patients_families/EdMat/third_batch/Premature%20Adrenarche.pdf
http://www.childrenshospital.org/conditions-and-treatments/conditions/p/premature-adrenarche/treatments
https://www.uptodate.com/contents/premature-adrenarche#H25
https://clinicaltrials.gov/

Search

+