Definition of central precocious puberty
Precocious puberty is the abnormal onset of puberty earlier than that of the patient's expected norm. As a generalization, this would imply the onset of a constellation of "secondary sex changes" prior to 8 years of age in girls and 9 years of age in boys. In comparison, routinely the onset of physical changes associated with the initiation of puberty is approximately 10 and a half years of age in girls and 11 and a half years of age in boys.
What are the types of precocious puberty?
Precocious puberty is routinely subdivided into three types.
- Central precocious puberty is associated with the premature activation and elevation of the cascade primary brain sex hormones necessary to cause the release of elevated secondary sex hormones. These secondary sex hormones are released by the child's gonads (ovaries and testes) as a normal response to the rise in primary sex hormones.
- Peripheral precocious puberty is associated with the abnormal rise of hormones released, independent of brain hormones, by the ovaries or testes that cause the development of secondary sex changes. The brain hormones are not elevated.
- Benign (non-pathological and non-progressive) development of single secondary sex changes (such as early development of body odor). These sex changes are often considered to be variants of routine sexual development and are not associated with abnormal elevation of the child's sex hormones.
Medical Conditions Tied to Early Puberty
Precocious puberty is much more common in girls than in boys. Many girls experience precocious puberty in the absence of any disease or condition. In boys, however, precocious puberty is more likely to be associated with an underlying medical problem. While in many cases the exact cause of precocious puberty cannot be determined, a small number of cases are related to abnormalities of the ovaries or testes, thyroid gland abnormalities or other hormone problems, genetic conditions, tumors or infections of the brain, and injury to the brain.
What causes and risk factors of central precocious puberty?
Central precocious puberty is due to the premature maturation of the sex hormones originating in the brain. The elevation of these hormones, in turn, cause elevation of the sex hormones made in the ovaries/testes and adrenal glands that produce the secondary sex changes detailed above.
It is essential to have a complete evaluation to determine the cause of the elevation of primary and/or secondary sex hormones patient with precocious puberty. Such an evaluation will allow classification of whether the patient has central, peripheral, or benign precocious puberty. With respect to female central precocious puberty, approximately 80%-90% have no underlying pathology. However, the large majority of boys with precocious puberty have a definable lesion causing their symptoms and signs.
The causes of central precocious puberty include
- brain tumors,
- brain trauma, and
- brain radiation (such as to treat brain cancers).
A risk factor for the development of primary precocious puberty can be the presence of genetic mutations. Such mutations are rare. Other causes for the onset of central precocious puberty are abnormalities of organs (such as the adrenal glands) that are associated with elevation of hormones that in turn feed back to the brain, causing elevation of sex hormones.
What are the signs and symptoms of central precocious puberty?
"Secondary sex changes" are those physical changes associated with the progressive rise in sex hormones -- estrogen and progesterone in females and testosterone in males. Such secondary sex changes include
- breast tissue development,
- enlargement of the testes (testicles) and penis, and
- presence of pubic hair, axillary hair, and facial hair.
Other developmental changes include
- initiation of menstrual periods,
- increasing in sweat production,
- development of body odor,
- lowering of the pitch of voice, rapid height acquisition ("growth spurt"), and
- increase in size and strength of muscles.
How do health-care professionals diagnose central precocious puberty?
The diagnosis of central precocious puberty requires a complete and thorough history and physical examination. Historical elements include the onset of secondary sex changes from parental report, any changes of intellectual or physical agility capabilities, and the onset of other potential hormone gland abnormalities (including loss of visual acuity or visual field, increase in urinary output, progressive weight gain or loss, etc.). A family history regarding the onset of secondary sex changes, growth patterns, or other historical risk factors is important to explore. Physical exam includes documentation of breast development, size of the testes and penis, examination of pubic, axillary, and facial hair (in males) The onset of menstruation and a rapid growth in height or muscular development is also important to document. Blood studies, X-rays, and brain imaging (CT and MRI scans) are commonly part of the child's evaluation.
What is the treatment for central precocious puberty?
The treatment of central precocious puberty reflects the identification of the primary cause of the child's disease. Brain surgery, hormonal therapy, nonhormonal medications, and other techniques are all options depending upon the primary cause for the child's condition.
What is the prognosis of central precocious puberty?
Similar to the treatment of central precocious puberty, the prognosis is related to the precise cause of the child's disease. Since, in general, the cause of female central precocious puberty is less likely to be ominous when compared to a male child, the prognosis reflects this gender bias. A child being evaluated for precocious puberty should have their case handled by pediatric specialists found at a teaching/university-affiliated pediatric hospital.
Harrington, Jennifer, and Mark Palmert. "Definition, Etiology, and Evaluation of Precocious Puberty." UpToDate.com. Mar. 21, 2016.
Long, Dominique. "Precocious Puberty." Pediatrics in Review 36.7