Precocious puberty

Precocious puberty (pubertas praecox) is defined as an acceleration of the onset of puberty by more than 2.5 standard deviations from the mean value of the population norm. Ie. is characterized by the onset of development of secondary sexual characteristics (breast augmentation, hair growth, voice changes, muscle growth, beard, and changes in body fat storage) before the 8th birthday in girls and before the 9th birthday in boys.These children are initially taller than their peers, but the growth period is shorter and the resulting height is lower.

Early puberty (constitutional acceleration) is defined as the acceleration of the onset of puberty by 2–2.5 standard deviations from the age population norm, ie. between 8 and 9 years for girls and between 9 and 10 years for boys. This is a variant of normal development.

Classification
Incomplete forms


 * thelarche praecox, adrenarche praecox, rarely menarche praecox.

Complete forms


 * central (pubertas praecox centralis) - gonadoliberin and gonadotropin-dependent;
 * premature activation of the hypothalamic-pituitary-gonadal axis;


 * peripheral (pseudopubertas praecox) - gonadoliberin and gonadotropin-independent;
 * premature production of sex hormones without stimulation from higher centers.

Incomplete forms of precocious puberty

 * relatively common
 * considered as a variant of normal development;
 * isolated premature thelarche (premature breast development)
 * usually in girls under 2 years of age, sometimes at birth;
 * causes: external source of estrogen (breastfeeding mothers, some foods containing hormones, endocrine disruptors in the environment, mother using cosmetics with hormonal extracts) or own production of estrogens with slower onset of inhibition by feedback and central mechanisms, perhaps increased tissue sensitivity to extrogens;
 * transition to central precocious puberty is rare, growth and outcome are not affected.
 * isolated premature adrenarche (premature development of pubic and axillary hair)
 * usually aged 6-7 years;
 * more often in obese children with hyperinsulinemia and in children who have undergone intrauterine growth retardation;
 * is not accompanied by total biological acceleration; in some girls, polycystic ovary syndrome is in adulthood.

Complete forms of precocious puberty

 * accelerated growth and bone maturation; psyche and behavior do not correspond to calendar age;
 * without treatment, the final height is reduced.

Central (gonadotropin-dependent) precocious puberty

 * about 0.6% of children; much more common in girls;
 * about half of the cases manifest before the age of 6;
 * cause: CNS (hypothalamus, pituitary gland);
 * hormone levels: FSH and LH elevated (pubertal), sex hormones (estrogens / testosterone) elevated;
 * secondary sexual characteristics present; symmetrically enlarged (pubertal) testicles / ovaries;
 * sexual development is always isosexual = consistent with biological sex;
 * in girls most often idiopathic (in 70-80%, sometimes with familial occurrence);
 * in boys, the cause is mostly organic (up to 65%);
 * etiology: idiopathic, CNS tumors (hamartoma, astrocytoma, adenoma, glioma, germinoma), inflammatory CNS diseases, head injuries, iatrogenic causes (radio-, chemotherapy, surgery), CNS malformations.

Precocious pseudopuberty

 * cause: gonads, adrenal glands;
 * hormone levels: FSH and LH low (prepubertal), sex hormones increased;
 * secondary sexual characteristics present;
 * sexual development can be isosexulation (according to biological sex) or heterosexual (virilization in girls, feminization in boys);
 * etiology:
 * adrenal steroidogenesis blockade (congenital adrenal hyperplasia, CAH);
 * testosterone / androgen producing tumors: adrenal, ovarian, testicular;
 * tumor-producing gonadotropin / hCG;
 * external hormonal source of androgens / estrogens;
 * familial testotoxicosis - a rare AD activating mutation of the luteinizing hormone receptor → in boys premature isosexual pseudopuberty in the first years of life;
 * McCune-Albright syndrome - isosexual premature pseudopuberty in girls with focal ovarian activation, fibrous bone dysplasia, skin spots café au lait;
 * ovarian cysts;
 * long-term untreated hypothyroidism.

Diagnosis

 * age of the first symptoms of puberty and their progression, growth dynamics, bone age and the degree of sexual development according to Tanner;
 * serum levels of FSH, LH, estradiol / testosterone, TSH, fT4, DHEA or DHEAS;
 * gonadoliberin stimulation test (GnRH or LH-RH test) to detect central precocious puberty;
 * after stimulation, gonadotropin levels are elevated in central puberty and low in pseudopuberty;
 * brain MRI to rule out the organic cause of central precocious puberty;
 * USG of the adrenal glands, testicles or uterus and ovaries;
 * hormonal (functional) cytology of the vaginal mucosa.

Treatment

 * incomplete forms are not treated;
 * complete forms are treated according to the cause:
 * central precocious puberty: depot gonadotropin-releasing hormone agonists (blocking pituitary receptors for endogenous gonadoliberin and thus stopping sexual development - slowing down bone maturation or closure of bone fissures), the best effect when started before the age of 6;
 * treatment is stopped when the bone age usual for pubertal growth spurt is reached, ie at 12 years of age for girls and at 13 years of age for boys;
 * premature pseudopuberty - if causal treatment fails, the following can be used: ketoconazole to inhibit steroidogenesis, spironolactone to inhibit androgen receptors, and tamoxifen to inhibit estrogen receptors.

Related articles

 * Endocrine diseases of the gonads • Estrogens • Gestagens
 * Puberty • Pubertas tarda