Precocious puberty: why does a child grow up prematurely?

Precocious puberty (pubertas praecox) occurs in girls before the age of eight and in boys before the age of nine.

Puberty is the period of onset of sexual maturation until sexual adulthood.

It is a very challenging period that every individual goes through.

This period is characterized by physical, psychological and social changes. These include bone growth, changes in body shape and genitalia.

The trigger for puberty is the hormonal changes taking place in the child's body.

Physiologically, puberty begins between the ages of 11 and 15.

In girls, it begins on average between the ages of 10 and 11. Menstruation occurs on average at 13.

In boys, puberty begins around age 11. By age 17, most boys reach their final height.

Puberty has two phases

The first pubertal phase is also referred to as prepubertal (11-13 years).

During this period, the first characteristic sexual changes appear. In girls, the onset of menstruation is most common between the ages of 11-13. In boys, nocturnal seminal discharge occurs 1-2 years later.

The second phase, the actual puberty phase, comes around 13-15 years. This period lasts until the attainment of reproductive capacity.

In girls, the first menstrual period is irregular. It takes 1-2 years to adjust the cycle.

Delayed puberty(pubertas tarda) is spoken of when a girl at 13 or a boy at 14 has no signs of puberty.

The onset of puberty is often conditioned by genetic factors. In girls, it occurs around the age of onset of puberty in the mother, but is also conditioned by environmental and nutritional factors.

The course of puberty has its own terminology

• Thelarche is manifested by breast development and is a response to the hormone estrogen
• Pubarche is a reaction to androgens and is manifested by the development of pubic hair
• Adrenarche contributes to pubarche, the development of pubic hair as a consequence of the onset of androgen production by the adrenal glands

Precocious puberty refers to the development of pubertal features such as genital growth, pubic hair, breast growth, before the age of 8.

This sign cannot be underestimated. The cause should be identified and treatment initiated to prevent further complications such as growth arrest.

Precocious puberty occurs in approximately 0.6% of children. It affects girls rather than boys.

Types of precocious puberty

Central precocious puberty (oubertas praecox vera) is also referred to as true precocious puberty. It is caused by premature activation of the hypothalamic-pituitary-gland axis.

It occurs 4-7 times more frequently in girls than in boys.

In true precocious puberty, the sequence of development of pubertal features follows the sequence of normal physiological puberty. The difference is only in the age of the child.

Peripheral precocious puberty (seudopubertas praecox) is called pseudopubertal precocious puberty. Its cause is usually overproduction of hormones or excessive steroid intake.

The typical symptom is accelerated growth and development of bone maturation.

Physiological puberty begins with the production of gonadotropin-releasing hormone.

When this hormone reaches the pituitary gland (brain), it leads to increased production of estrogen in the ovaries in girls or testosterone in the testes in boys.

The hormone estrogen promotes the growth and development of female sex characteristics.

Testosterone is responsible for the growth of male characteristics.

The cause depends on whether the child has central or peripheral precocious puberty.

Causes of precocious puberty

Central precocious puberty

Central precocious puberty depends on the hormone gonadotropin. In most cases, its cause is unknown.

This type of precocious puberty is due to earlier maturation and premature activation of the hypothalamic axis.

In most children, there is no problem or reason for the onset of precocious puberty.

In some cases it is due to an unknown cause. It may be familial, genetically determined, accounting for 70-80% of cases.

Other causes may be organic causes, such as:

• various traumas - head injuries, cranial irradiation, cerebral palsy, infection
• acquired abnormalities of the central nervous system (CNS)
• birth defects in the brain (hydrocephalus, haematoma)
• after brain and spinal cord irradiation, brain or spinal cord damage after chemotherapy
• after central nervous system surgery
• tumours of the central nervous system
• brain and spinal cord tumours
• untreated long-term hypothyroidism, where the thyroid gland does not produce enough hormones
• genetics and family history of precocious puberty

An organic cause is more common in boys.

Peripheral precocious puberty

Peripheral precocious puberty (pseudopubertas praecox) is independent of gonadotropins. It is caused by the production of sex hormones but in a non-physiological order compared to normal puberty.

Hormone production is caused by a different mechanism than central precocious puberty and occurs in disease:

• adrenal diseases
• ovarian tumours
• testicular tumours
• excessive administration of sex steroids
• ovarian cysts
• in boys - tumours in testosterone-producing cells or sperm cells
• congenital adrenal hyperplasia
• McCune-Albright syndrome (CAH)
• familial precocious puberty restricted to males (testitoxicosis)

Precocious pseudopuberty can also be caused by sex hormones ingested in the form of diet or cosmetic products (sunscreens, shampoos containing placenta, nail polishes).

Incomplete precocious puberty

This is the development of only some signs of adolescence without signs of accelerated growth. This type remains under observation and is not treated in any way as it is considered a benign condition.

It includes

• Hablan's reaction, which is typical of newborns. It is manifested by enlargement of the mammary glands under the influence of the hormone estrogen. This condition corrects itself without treatment.
• Telarche praecox occurs quite frequently. It is manifested by premature breast development in girls up to 8 years of age without other signs of puberty.
• Adrenarche praecox is characterized by premature growth of pubic or axillary hair.

Risk factors

• Precocious puberty is more common in girls
• Obesity
• Exposure to hormones, medications, creams, diets containing testosterone or estrogen hormones
• Health problems
• Radiation to central nervous system for treatment of tumors, leukemia

The symptoms of puberty are slightly different for both sexes.

Precocious puberty is manifested in girls

• sudden physical growth
• breast enlargement
• Later, hair on the genitals and armpits
• the onset of menstruation
• acne
• body odour as in adults
• Accelerated growth also accelerates bone maturation. If left untreated, it results in lower final height due to premature closure of growth gaps

Precocious puberty manifests itself in boys

• testicular enlargement
• darkening of the skin on the testicles
• the penis enlarges
• pubic hair growth follows
• erection occurs
• nocturnal pollutions (involuntary discharge of semen) with already functional sperm
• thickening of the voice

In boys, precocious puberty is rare.

Precocious pseudopuberty may take the form of

The isosexual form, in which the development of sexual characteristics in both sexes proceeds in the same way as in physiological puberty.

In this form, there is accelerated bone development. This worsens the growth prognosis and without treatment, the final height is much lower.

The heterosexual form, in which development and growth typical of the opposite sex occurs.

In girls, there is enlargement of the clitoris and also increased facial hair such as moustache hairs.

In boys, the genital hair does not typically end horizontally as in men. It runs out towards the navel, which is typical of the female sex. In boys, the breasts also increase in size and there is a feminine distribution of fat.

When precocious puberty is suspected, a number of examinations are carried out.

Diagnosis focuses on the history of the child and family members. The age of first symptoms, the speed of their development and the degree of sexual development are observed.

If the disease has already occurred in the family, the onset of pseudopuberty may be genetically accelerated.

The child is referred to an endocrinologist, neurologist, ophthalmologist and gynaecologist for an eye examination. The girl is also referred to a gynaecologist.

A Tanner scale examination of pubertal development is useful, which assesses the development of primary and secondary sex characteristics typical of the child's age.

If precocious puberty is suspected, examinations are performed to confirm it.

• Blood sampling to determine hormone levels and thyroid function
• Gonadoliberin stimulation test to confirm central precocious puberty
• An X-ray of the left hand and wrist is taken. The age of the child is determined. In precocious puberty, it indicates rapid bone growth and reflects an estimate of further development and growth. This will determine the approximate height at adulthood
• Sonography of the small pelvis in girls, where the ovaries and uterus are examined, and the testicles in boys.
• CT scan
• Magnetic resonance imaging of the brain to rule out an organic cause

In boys, both testicles are examined at diagnosis.

Enlargement of both testicles is due to increased secretion of gonadotropins from the pituitary gland. Onset of true puberty is assumed, but tumour, CNS lesions must also be excluded.

Enlargement of the genitalia without testicular growth and growth of pubic hair originate in the adrenal glands from steroid production and indicate false puberty.

Enlargement of only one testicle occurs with testicular tumor.

Children with precocious puberty may feel differently from their peers.

They perceive changes in their bodies that are sometimes difficult for them to process. This can lead to psychological problems.

Children can be confused, moody and irritable. Boys can be more aggressive.

Children become prematurely interested in the opposite sex, feel arousal and jerk off.

Children suffer from impaired concentration at school. They feel different, which causes problems of integration into the group.

In precocious puberty, girls experience breast growth before the age of 7-8, onset of menstruation before the age of 10 and rapid growth in height before the age of 7-8.

A precocious pubertal child may be taller and more robust in appearance than children in his or her age group.

In boys, precocious puberty is manifested by testicular and penile enlargement, rapid growth, growth of pubic and facial hair, and voice mutation.

It is common in both sexes

• pubic hair growth, armpit hair growth
• Acne
• Mature body odour characteristic in adulthood

Children's growth in height also stops after puberty.

In gonadotropin-independent precocious puberty, the course is different, especially in the order of development of sexual characteristics. For example, growth of the penis without concomitant testicular enlargement.

A complication associated with precocious puberty is short stature. Children stop growing earlier than their peers.

Emotional problems appear in children as a result of becoming aware of the changes that are happening to their bodies. This can affect their psyche and self-esteem and increase the risk of depression.