Precocious Puberty

What is Precocious Puberty?

Puberty is a complex period of transition for kids. It generally involves growth spurts and the emergence of adult sexual features. It’s a time of physical and mental development. A mix of various elements, such as genetics, the environment, and diet, contribute to the start and progression of puberty.

The changes of puberty are driven by the activation and maturation of a system called the hypothalamic-pituitary-gonadal (HPG) axis. When a baby first comes into the world, there’s usually a brief activation of this system, leading to increased production of hormone steroids. These hormones can cause breast development in newborn girls and pubic hair growth in newborn boys, a phase often referred to as “mini-puberty” that recedes by the time the child is about two. This phase is generally harmless, but not much information is known about why it happens and what it means.

Following this, the HPG axis isn’t active for some years until it switches back on during adolescence. At this time, the increase in the release of certain hormones – GnRH from the hypothalamus, FSH and LH from the pituitary gland – starts the process of sperm production and testosterone release in boys and egg production and estradiol release in girls.

Certain terms are used when tracking the progress of puberty. Thelarche refers to the growth of breasts, a response to estrogen. Pubarche is the appearance of pubic hair, a response to androgens. Adrenarche is the start of adrenal androgen production, which contributes to pubarche.

Normally, the secondary sexual features appear around age eight for girls and nine for boys. If these features start forming earlier, this is considered ‘precocious puberty’.

What Causes Precocious Puberty?

Precocious puberty, which is the unusually early start of puberty, can be grouped into two main types based on what causes it:

* Central precocious puberty (GnRH dependent)
* Peripheral precocious puberty (GnRH independent)

Central Precocious puberty (CPP) is real puberty that starts too soon because the puberty control center in the brain (known as the HPG axis) matured and activated earlier than it should have. This often happens for no clear reason in girls, but in boys, it’s usually caused by some underlying health issue. It could come from a range of factors, such as:

* Brain tumors – a range of different types can potentially cause CPP
* Brain injury – this could be from head injuries, radiation to the head, cerebral palsy, or infections like tuberculosis in the brain
* Genetics – mutations in certain genes can lead to CPP
* Syndromes – specific conditions like Neurofibromatosis type 1 and Tuberous sclerosis
* Environment – children adopted internationally and stopping hormone therapy can also lead to CPP
* Some families may have several members with CPP

The most common cause of CPP is a brain lesion called a hypothalamic hamartoma. This issue in the brain functions like an extra puberty control center, and it leads to signs of puberty in very young children, sometimes as early as 12 months old. It’s often linked to a type of seizure that’s hard to control with medicine, and other issues like poor cognition, behavioral problems, and psychiatric symptoms. It seems to be more common in children adopted from other countries. We’re not sure why, but it may be due to better nutrition or exposure to chemicals that interfere with hormones. Some families seem to have higher rates of CPP, but the genetic causes aren’t well understood. Certain genes that control the release of puberty-starting hormones (GnRH) seem to play a role. If these genes don’t work as they should, it can result in CPP.

Peripheral Precocious Puberty (PPP) causes early puberty symptoms due to sex hormones being produced from inside or outside the body. It doesn’t involve the brain’s puberty control center (GnRH). This type of precocious puberty is less common than CPP. Some possible causes include:

* A condition called Congenital adrenal hyperplasia
* McCune-Albright syndrome
* Testicular or ovarian tumors
* Adrenal gland tumors
* Familial male-limited precocious puberty (a condition that only affects males)
* Being exposed to sex hormones from outside the body
* Van Wyk and Grumbach syndrome

Tumors are a rare cause of PPP. In some cases, more androgens (male sex hormones) are produced due to certain diseases, adrenal glands tumors, and specific types of testicular tumors. Some tumors produce increased amounts of a hormone called human chorionic gonadotropin (hCG). Testitoxicosis is a rare condition that results in precocious puberty specifically in boys. This happens due to a mutation that activates specific cells in the testes causing high testosterone levels. Van Wyk and Grumbach syndrome is associated with low thyroid function, ovarian cysts and early puberty. McCune-Albright syndrome causes a range of symptoms that include precocious puberty, bone issues, unusual skin coloring, and possibly other hormone issues caused by a specific genetic mutation.

Risk Factors and Frequency for Precocious Puberty

Precocious puberty, or early puberty, is a condition that hasn’t been widely studied. According to limited data, it affects around 0.2% of girls, and less than 0.05% of boys. It’s more common in girls, affecting about 20 to 23 girls out of every 10,000. For boys, this figure is less than 5 out of every 10,000. The number of new cases each year varies quite a bit. In Spain, for instance, it’s estimated that new cases range from 0.02 to 1.07 out of every 100,000 people annually. In Korea, there are about 55.9 girls and 1.7 boys diagnosed with early puberty for every 100,000 children. Similarly, the rate of new cases in Korea is about 15.3 girls and 0.6 boys per 100,000 annually. Different places in the world might see different rates, making it tricky to provide precise numbers.

• Precocious puberty affects about 0.2% of girls and less than 0.05% of boys.
• The condition is more common in girls, with around 20 to 23 cases per 10,000 girls compared to less than 5 per 10,000 boys.
• The number of new cases each year ranges considerably. In Spain, it’s estimated to be between 0.02 and 1.07 cases per 100,000 people annually.
• In Korea, about 55.9 girls and 1.7 boys per 100,000 children are diagnosed with early puberty.
• The annual rate of new cases in Korea is about 15.3 girls and 0.6 boys per 100,000 children.
• The rates can differ significantly depending on geographic location.

Signs and Symptoms of Precocious Puberty

Precocious puberty is when a child’s body begins developing into that of an adult (puberty) too soon. Symptoms vary between boys and girls. Girls might show early breast development, while boys might have an increase in their testicle’s size over 4 ml. Both might experience a growth spurt, acne, body odor, and development of pubic and underarm hair.

If you suspect early puberty, it’s important to determine whether these signs are coming on sooner than usual. Sometimes, normal puberty begins at the right age but progresses too quickly, which is also abnormal. Health professionals will also look out for signs of neurological problems, like headaches, seizures, and changes in sight or thinking. These could be signs of problems in the brain’s pituitary gland, which helps regulate hormone levels. Symptoms like increased peeing and drinking, and decreased growth speed could also suggest pituitary problems.

• Breast development in girls
• In boys, increased testicular volume (greater than 4 ml)
• Increased growth speed
• Acne
• Muscle changes
• Body odor
• Pubic and underarm hair development

You may also be asked about issues like stomach pain, which could point to problems with the ovaries, and about any head injuries, infections, or drug use that could impact hormone levels. Your family history of puberty onset can also be informative about whether the early development is a genetic trait.

Close attention is paid to speedy growth, so your child’s height, weight, rate of growth, and body mass index (BMI) will all be documented. In girls, accurate observation of breast size increase is critical, but it can be challenging in overweight girls. In boys, a tool called an orchidometer may be used to measure testicle size. If a child is developing body odor and pubic hair but isn’t growing breast tissue or larger testicles, further investigation is needed. One-sided testicle enlargement should also be assessed to rule out tumors. Finally, signs of skin conditions like dark, velvety patches (acanthosis nigricans), café au lait spots, or nerve-related tumors (neurofibromas) may indicate disorders like neurofibromatosis type 1 and McCune-Albright syndrome, which can trigger early puberty.

Testing for Precocious Puberty

When going for initial screening tests for hormonal health, a wide range of tests might be done. These could include checking your bone age and levels of various hormones like Luteinizing hormone (LH), Follicle-stimulating hormone (FSH), Testosterone, Dehydroepiandrosterone sulfate (DHEA-S), 17 OH progesterone, as well as tests for thyroid functions.

Bone age is one of the initial tests doctors perform. If your bone age is found to be considerably older than your actual age, you may require further testing. This is because an older bone age might suggest some health conditions.

Testing for hormone levels can help figure out if the cause of growth problems is in the central part of your body (brain and spinal cord) or elsewhere. For example, if the level of LH hormone is greater than 0.3 IU/L then it could indicate a condition known as Central Precocious Puberty (CPP), which is early onset puberty due to issues in the brain. Levels under 0.3 might suggest that the cause is not due to the brain but could be due to other organ systems or a harmless variant of normal growth. If a doctor suspects CPP, there is a specific test they might do which is considered the gold standard. This test is however not available in the United States, so an alternative is used.

Tracking levels of FSH does not usually provide much useful information. However, very high levels of estradiol in females or testosterone in males, coupled with low LH and FSH, could suggest Peripheral precocity. This is a condition caused by early secretion of sex hormones from the ovaries, testes, or adrenal glands.

The hormone called Dehydroepiandrosterone sulfate (DHEAS) is also measured to understand if the source of certain sex hormones is the testes or the adrenal glands. These are small glands that sit on top of each of your kidneys and produce important hormones.

For boys, doctors should consider testing the levels of the hormone called Human chorionic gonadotropin (hCG). Some types of cell tumors can release this hormone which stimulates the production of testosterone.

If Peripheral Precocious Puberty (PPP) is suspected, doctors might use imaging tests called ultrasonography. For girls, this could help identify any tumors or cysts in the ovaries. For boys, ultrasonography might reveal tumors in the male reproductive gland cells called Leydig cells.

Lastly, in cases of CPP, Magnetic resonance imaging (MRI) is done to ensure there are no issues in a part of the brain called the hypothalamus. Even in girls, this MRI investigation might be considered if puberty changes start very early (less than 6 years of age).

Treatment Options for Precocious Puberty

Central precocious puberty is a condition where a child’s body starts changing into that of an adult too soon. Whether treatment is necessary will depend on the child’s age and how fast these changes are happening. If symptoms are progressing quickly or if the child’s bones are maturing significantly faster than expected, treatment might be needed. The main goals of the treatment are to ensure that the child grows to their full potential height as an adult and to address any emotional stress linked to these early changes.

The standard treatment involves medicines called GnRH agonists. There are many forms of these medicines, including nasal sprays, injections into muscle, and injections under the skin. The specific type used will depend on what’s best for the child and doctor’s preference. In the US, a medicine called leuprolide acetate is commonly used. This is given as an injection every three months.

These medicines are generally considered safe, with no major reported side effects. Some common side effects include skin reactions where the medicine is injected and symptoms similar to menopause such as hot flashes. While the child is receiving treatment, they will be monitored to see how they are growing and developing.

Peripheral precocious puberty, on the other hand, is addressed by removing the source of hormones causing the early changes. In some cases, this could mean surgery to remove tumors on the adrenal glands or other glands that produce these hormones. If the child is exposed to these hormones from outside sources, measures should be taken to remove these. In some rare cases, specific medical conditions may need different treatments like estrogen-blocking medicines or a combination of hormone-blocking medicines.

What else can Precocious Puberty be?

When dealing with precocious puberty, it’s important to distinguish it from harmless forms of puberty. These might include:

• Premature Thelarche: This is when a girl between 12 to 24 months old develops breast tissue prematurely. It may happen on one or both sides. No other signs of puberty show up. Growth rate, bone age, and biological tests are all normal. However, this diagnosis is usually only made when other possibilities have been ruled out. Regular check-ups are needed to keep track of growth and puberty progress.
• Premature Adrenarche: This harmless condition is the early creation of adrenal androgen hormones. It can result in pubic or armpit hair, body odor, or acne before the age of 8. In girls, there is no breast development, and boys do not experience growth in their testicles. The bone age usually does not advance. It’s important to rule out exposure to androgen sources like creams or gels, adrenal tumors, or late-onset Congenital Adrenal Hyperplasia (CAH).
• Premature Menarche: This happens when a girl under the age of 7 experiences vaginal bleeding. It could be a one-time occurrence or a few cycles (less than 3) of bleeding, and the progression to puberty is normal. Current research suggests that it does not affect adult height. It’s important to rule out sexual abuse, vaginal foreign bodies, and infections of the vulva and vagina.

What to expect with Precocious Puberty

Starting treatment early can lead to better results in maintaining normal height growth. The final result depends on several factors such as how advanced the bone changes are, the age when early puberty started, when treatment was started, and how long the treatments last. The Hypothalamus-Pituitary-Gonad (HPG) axis – which is the system involving the brain and reproductive organs – tends to return to normal after treatment stops, and children often experience normal puberty after this.

However, there is limited information on the long-term effects of the treatment on the body’s hormones, metabolism, and reproductive system, along with psychological impacts.

The prognosis or outlook for premature puberty varies, based on its cause.

Possible Complications When Diagnosed with Precocious Puberty

Precocious puberty, which is early puberty, if left untreated usually results in the affected children being short when they reach adulthood. This condition can also lead to significant emotional and behavioral problems. According to some studies, children with precocious puberty have a higher risk of involvement in high-risk behaviors like misuse of substance, behavioral problems, feeling of loneliness, regular absence from school, and having multiple sexual partners. They also tend to struggle with peer pressure and worries about their self-image.

Possible challenges faced by kids with precocious puberty:

• Early growth cessation resulting in short height
• Emotional and behavioral issues
• Engagement in risky behaviors
• Social isolation
• Issues with school attendance
• Multiple sexual partners
• Struggle with peer pressure
• Insecurities about their self-image

However, it’s important to note that most of these problems typically get resolved when these kids reach early adulthood. That being said, additional research is required to understand fully the psychological effects of precocious puberty.

Preventing Precocious Puberty

Both primary care doctors and children’s hormone specialists should engage in thorough discussions about early signs of puberty, even if it’s a harmless variation. If there’s a need for treatment, they should talk about how long it will last and any potential side effects. In addition, parents should learn how to explain the situation to their children and other family members.

Educational resources for parents can be found through the Pediatric Endocrine Society and the American Academy of Pediatrics’ Section on Endocrinology Patient Education Committee. These materials can be very helpful when trying to understand and explain what is happening.