Pubertal development is generally defined as precocious puberty when it occurs before the age of 9-9 1/2 years for boys and 8 years for girls. It can be divided into two categories: true (also known as central, complete) and pseudo (also known as peripheral, incomplete). Symptoms and signs 1. True precocious puberty True precocious puberty is caused by inappropriately premature initiation of hypothalamic-pituitary-gonadal axis function, which makes pubertal development appear early, and its performance is the same as normal developmental period, and the secondary sexual characteristics are consistent with genetic sex, which can produce sperm or eggs and have fertility. (1) Idiopathic precocious puberty: it is generally sporadic and is more common in females (female:male is about 4:1). A few of them can be familial (may be autosomal recessive inheritance). The etiology is unknown. In females, development usually occurs before the age of 8 years, and the sequence is breast development → pubic hair → menstruation → axillary hair, labial development (with pigmentation), and increased vaginal discharge. In males, sexual development occurs before the age of 9. The testes and penis grow, scrotal skin folds increase with deepening pigmentation, penile erection increases and even sperm production, muscles increase, and subcutaneous fat decreases. Both sexes show sudden growth and early bone age, which can eventually lead to premature epiphyseal fusion and shorter adult height. Psychosexual maturation is also advanced. (2) Precocious puberty due to central nervous system diseases: secondary to central nervous system diseases. Tumors located in the hypothalamus, such as mesencephalic malformation tumor, glioma, craniopharyngioma, etc. It is more common in boys. (3) Primary hypothyroidism (hypothyroidism) with precocious puberty: A few people with hypothyroidism before early childhood may have precocious puberty. The decrease in the level of thyroid hormone and the negative feedback increase the secretion of TRH in the hypothalamus, and TRH not only stimulates the pituitary gland to secrete more TSH, but also stimulates the secretion of PRL, LH and FSH, leading to precocious puberty. 2. Pseudoprecocious puberty is caused by factors other than gonadal axis to increase sex hormones, which shows that only secondary sex characteristics are developed, but no germ cells are matured simultaneously, so there is no fertility. Clinically, true precocious puberty is more than pseudoprecocious puberty. In this case, only some secondary sexual characteristics are present, but no germ cells (sperm and follicles) are matured, so there is no fertility. (1) Gonadotropin-secreting tumors (such as chorionic epithelial carcinoma or teratoma secreting human chorionic gonadotropin, liver tumors secreting LH-like substances, adrenal androgenic tumors, Leydig cell tumors), ovarian cysts and ovarian tumors (granulosa cell tumors, vesicular cell tumors, etc.) cysts, etc. (2) Exogenous estrogen or excessive intake of estrogen, such as misuse of birth control pills. (3) Congenital adrenal cortical hyperplasia (CYP21, CYPllβ1 deficiency, etc.). (4) McCune-Albright syndrome: Patients have skeletal dysplasia and brown pigmented skin on the trunk, often with precocious puberty. The etiology is unknown. It occurs in girls and very rarely in boys. The sequence of sexual development differs from normal: menarche (mature genital organs) is preceded by mammary gland development. Some of them can be transformed into central precocious puberty. Laboratory tests: 1. Measurement of plasma LH and FSH The measurement of plasma LH and FSH can help identify true or false precocious puberty. In true precocious puberty, FSH and LH pulse secretion peaks are mostly LH, and the decrease of FSH and LH indicates androgenic tumor. 2.Estrogen level measurement The estrogen level of true precocious puberty secreting estrogen tumor and exogenous pseudoprecocious puberty is obviously elevated, while the estrogen level of those with simple premature breast development is not high or slightly high. 3.GnRH stimulation test Central precocious puberty is sensitive to GnRH response, peripheral precocious puberty is unresponsive or insensitive. 4.Urine 17-ketone measurement 17-ketone is elevated in adrenal carcinoma and is not inhibited by dexamethasone. 5.Thyroxine function measurement To determine the relationship between precocious puberty and thyroid function. Other auxiliary examinations: cranial X-ray or CT and MRI examination, ultrasound of uterus, ovaries and testes or X-ray bone age examination, etc. Treatment 1, drug treatment (1) GnRH analog (GnRH-A): GnRH-A is currently the most effective drug for the treatment of true precocious puberty, GnRH-A continues to act on GnRH receptors, down-regulating GnRH receptors, making the pituitary LH-secreting cells less sensitive to GnRH, causing LH secretion to be inhibited and sex hormone levels to drop rapidly. The effect is reversible and the hypothalamic-pituitary-gonadal axis can return to normal after discontinuation of the drug. The use of extended-release formulations of GnRH-A, such as leuprorelin or treprostinil (Daphylline), has not been found to have significant side effects in long-term use, but should be discontinued at puberty age. (2) Tamoxifen or Amgen progesterone for ovarian cysts (3) Letrozole anti-estrogen and inhibit bone age 2. Surgery Tumors should be operated as soon as possible after diagnosis. Germ cell tumor is significantly reduced after irradiation, and precocious puberty can be significantly subsided. Diet and health care 1. Do not buy fruits and vegetables with strange shapes and colors, and pay more attention to them when they are out of season; 2. “The “ripening agent” residue in poultry meat is mainly concentrated in the glands of the head and neck part of poultry, try to avoid.