Pubertas praecox

Precocious puberty

Precocious puberty (La:pubertas praecox) is an unusually early onset of puberty, the process of sexual maturation triggered by the brain or exogenous chemicals, which usually begins in late childhood and results in reproductive maturity and completion of growth. Early puberty may be a variation of normal development, or may be a result of a disease or abnormal hormone exposure.

In some contexts, the term is used more broadly to describe the early appearance of any of the physical features of puberty even if the complete brain-directed process is not occurring.

Types

Early pubic hair, breast, or genital development may result from natural early maturation or from several other conditions.

a. Early puberty which is natural in every way except age is termed idiopathic central precocious puberty. It may be partial or transient. Central puberty can also occur prematurely if the inhibitory system of the brain is damaged, or a hypothalamic hamartoma produces pulsatile gonadotropin-releasing hormone (GnRH).

b. Secondary sexual development induced by sex steroids from other abnormal sources (gonadal or adrenal tumors, congenital adrenal hyperplasia, etc.) is referred to as peripheral precocious puberty or precocious pseudopuberty.

Clinical significance

Early sexual development deserves evaluation because it may:

induce early bone maturation and reduce eventual adult height
indicate the presence of a tumor or other serious problem
cause the child to become an object of adult sexual interest

Central precocious puberty can be caused by intracranial neoplasm, infection, trauma, hydrocephalus, and Angelman syndrome.Case Study

High levels of beta-hCG in serum and cerebrospinal fluid observed in a 9-year old boy suggest a pineal gland tumor. The tumor is called a chorionic gonadotropin secreting pineal tumor. Radiography and chemotherapy reduced tumor and beta-hCG levels normalized. "Central precocious puberty (CPP) was reported in some patients with suprasellar arachnoid cysts(SAC) [3], and SCFE occurs in patients with CPP because of rapid growth and changes of growth hormone secretion.

Bones can be considered older in individuals with early puberty beyond actual age of individual. Early puberty is marked by growth hormone problems resulting from various brain disorders.

Measures

Studies indicate that breast development in girls and pubic hair in girls and boys are starting earlier than in previous generations. As a result, "early puberty" in children as young as 9 and 10 is no longer considered abnormal, although it may be upsetting to parents.

No single age limit reliably separates normal from abnormal processes in children today, but the following age thresholds for evaluation will minimize the risk of missing a significant medical problem:

Pubic hair or genital enlargement in boys with onset before 9 years.
Breast development in boys before appearance of pubic hair and testicular enlargement.
Pubic hair before 8 or breast development in girls with onset before 7 years.
Menstruation in girls before 10 years.Suggested causes:
endocrine disorder
familial associations
abnormalities in the ovaries, testicles, or adrenal glands
structural problems in the brain
tumors that release hormones (estrogen, testosterone, etc.)

(For Suggested Causes and epidemiology of central form, see:Antoniazzi F, Zamboni G (2004). "Central precocious puberty: current treatment options". Paediatr Drugs 6 (4): 211–31. )

Causes

The causes of early puberty are not clear. Girls who are obese are more likely to physically mature earlier.

Bisphenol A (BPA) is a chemical used to make plastics, and is frequently used to make baby bottles, water bottles, sports equipment, medical devices, and as a coating in food and beverage cans. Scientists are concerned about BPA's behavioral effects on fetuses, infants, and children at current exposure levels because it can affect the prostate gland or mammary gland, and lead to early puberty in girls. BPA mimics and interferes with the action of estrogen-an important reproduction and development regulator.

Other notes

Medical evaluation is sometimes necessary to recognize the few children with serious conditions from the majority who have entered puberty early but are still medically normal.

Precocious puberty can make a child able to conceive when very young; the youngest mother on record is Lina Medina, who gave birth at the age of 5 years, 7 months and 21 days. An 8 year old boy had early puberty caused by a malignant intracranial germ cell tumor.

The role of the pineal gland in reproduction of other species of vertebrate suggest that the pineal gland does have significance in development and function of human reproductive axis. In a study using neonatal melatonin on rats, results suggest that elevated melatonin could be responsible for some cases of early puberty.