Premature sexual development
Last reviewed: 23.04.2024
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Premature puberty is characterized by early development of the mammary glands, early onset of the menstrual cycle and early pubic hair on the pubic in girls, an early increase in the external genitalia in boys. Hair in the armpits is not pronounced or absent. The body is developed proportionately, the growth in children of both sexes does not differ from peers, they do not lag behind in intellectual development, sexual attraction and masturbation are uncharacteristic.
True premature puberty, as a rule, is accompanied by infertility.
A careful neurological and ophthalmological examination is necessary, which at early stages may indicate the presence of a volumetric process in the hypothalamus.
In some individuals, the onset of the puberty period falls to an 8-year-old age and this may be a variant of the norm. If sexual development began earlier than this age, the patient should be examined.
The first place among the causes of the disease is occupied by tumor lesions of the central nervous system with an effect on the hypothalamic region. Significantly sharp is observed after the transferred encephalitis, meningitis, severe craniocerebral trauma. In some cases premature puberty of a constitutional nature is possible.
Biological aspect. Each of the fiscal signs of the puberty period can be thought of as a kind of biochemical study of a certain hormone. The increase in testes in boys is the first sign of the onset of sexual development and is associated with the entry into the blood of shock doses of the pituitary gonadotropin. The increase in mammary glands in girls and the penis in boys is associated with increased secretion of gonadal sex steroids. The appearance of pubic hair is a manifestation of the production of androgens in the adrenal glands. The growth of boys is accelerated when the testicle volume reaches 10-12 ml (when measured by the principle of comparison with orchid balls). Girls begin to grow more quickly as their breasts develop. The fourth stage of development of mammary glands is characteristic already for the beginning of menstruation (in the majority of girls). But this coherent development of pubertal characters can sometimes be disrupted. So, for example, with Cushing's syndrome, the growth rate of pubic hair can disproportionately outstrip the increase in testicular volume; when the hypothyroidism of the testicles is sufficiently high [the level of FSH is increased due to an even greater increase in the level of TSH], however, the rate of increase in growth is reduced.
Premature puberty in boys is manifested by the rapid growth of the penis and testicles, the increasing frequency of erections, masturbation, the appearance of pubic hair, the appearance of a specific odor of the body and uke. Accordingly, secondary sexual characteristics also change for girls. The most important and accompanied by far-reaching consequences "complication" is the growth retardation, caused by the fusion of the epiphyses with diaphysis. When examining such children, parents should be asked about certain endocrine symptoms of a general nature that characterize hypothalamic dysfunction: are there no polyuria, polydipsia, obesity, sleep disorders and temperature regulation. There may be signs of increased intracranial pressure and certain eye disorders.
Premature sexual development in girls occurs about 4 times more often than in boys. In this case, girls often fail to identify the cause, while 80-90% of boys can be identified. If the onset of the disease occurs at the age of up to 2 years, the cause can often be a hamartoma developing in the hypothalamus. On a computer tomogram, it looks like a rounded "non-reinforcing" formation.
Other (mostly rare) reasons:
- Tumors of the central nervous system and hydrocephalus.
- Condition after encephalitis or meningitis.
- McCune-Albright Syndrome.
- Craniopharyngioma.
- Tuberous sclerosis.
- Hepatoblastoma.
- Choriocarcinoma.
- Hypothyroidism.
Examination of the patient. Skull survey, bone age determination from X-ray examination, CT scan of the skull (head), urinary excretion of 17-ketosteroids, ultrasound of the pelvis (in girls), determination of blood T4.
Differential diagnosis. First of all it is necessary to exclude tumors of testicles or ovaries. A thorough gynecological examination should be the first step in the diagnosis. With tumors of the adrenal cortex, premature pseudo-maturation occurs, in which hirsutism is markedly expressed, premature ossification of the epiphyses and, accordingly, low growth, obesity and hypertension are noted. There are no true menstrual cycles. As a rule, early-onset menstruation quickly transform into persistent amenorrhea. Should be differentiated from Albright's disease, developing only in girls, and from neurofibromatosis Recklinghausen, which is often the cause of premature puberty in girls.
Physiology and treatment of premature puberty
Treatment should be aimed at eliminating the underlying cause that caused the disease. With premature puberty of a constitutional nature, special treatment is not required.
The onset of the pubertal period depends on the cessation of inhibition of neurons in the medial basal part of the hypothalamus, where the gonadotropin-releasing hormone (GnRH) is secreted, as well as from the decrease in hypothalamic-pituitary sensitivity to negative feedback with gonadal steroids. These changes are accompanied by a significant increase in the frequency and power of the sharp "tides" (in the blood) of the luteinizing hormone (LH) and to a lesser extent - follicle-stimulating hormone (FSH). And it is the ability to secrete "pulse" amounts (shock amounts) of GnRH at high speed and causes a normal gonadal function. Constantly maintained in the blood, high concentrations of GnR paradoxically suppress the secretion of pituitary gonadotropins, which creates a basis for the treatment of premature puberty by synthetic analogues of GnRH.
After subcutaneous application or after nasal insufflation of drugs, the gonadal maturity and all clinical correlates of the pubertal period reverse (except for pubic hair, as there is no change in the secretion of androgens by the adrenal cortex). The rate of maturation of the skeleton also decreases. Treatment continues until the average pubertal age or before the arrival of menstruation (up to about 11 years). In the family of such patients, the doctor should give hope that the sick child will continue to develop normally.
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