Precocious Puberty

Basics

Description

  • Defined as the appearance of secondary sexual characteristics before the age of 8 years in girls and 9 years in boys
  • Normal puberty occurs between age 8 and 14 years in girls and 9 and 14 years in boys (1,2).
  • There are three types:
    • Gonadotropin-dependent precocious puberty (GDPP) or central precocious puberty; manifests secondary sexual characteristics in harmony such as bilateral breasts or testicular enlargement
    • Gonadotropin-independent precocious puberty (GIPP) or peripheral precocious puberty. Does not manifest secondary sexual characteristics in harmony. It presents a clinical picture of incomplete puberty.
    • Incomplete precocious puberty such as premature adrenarche and premature thelarche

Epidemiology

  • More prevalent in African American children compared to white children
  • Attention to racial differences is advised because African American girls normally develop secondary sexual characteristics at an earlier age than white girls.
  • It is 10 times more common in girls than in boys.
  • 80–90% of affected girls have idiopathic central precocious puberty (1,3).

Incidence
Estimated incidence of 0.01–0.05% per year in the United States (1)

Prevalence
In a population-based Danish study from 1993 to 2001, it was found that 0.2% of Danish girls and <0.05% of Danish boys were affected by some type of precocious puberty (3).

Etiology and Pathophysiology

  • GDPP (4)
    • Caused either by a central dysregulation of the hypothalamic-pituitary-gonadal axis resulting in overproduction of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) or by ectopic hormone production such as hCG by a neoplasm
    • Characterized by pubertal levels of FSH and LH
    • Affected individuals have advanced bone age and short stature due to premature epiphyseal closure.
    • Different causes include the following:
      • Idiopathic central precocious puberty is the most common type.
      • CNS lesions such as glioma, astrocytoma, hypothalamic hamartoma, and arachnoid cysts
      • Congenital CNS anomaly such as hydrocephalus
      • Infection such as encephalitis and meningitis
      • Trauma
      • CNS irradiation
      • Primary hypothyroidism
      • Gain-of-function mutation of the GPR54 protein, which is part of an essential signaling complex for the initiation of puberty
  • GIPP (1)
    • Caused by excess secretion of androgens or estrogens produced from the gonads or adrenal glands or from exogenous sources
    • FSH and LH levels are in the prepubertal range.
    • Causes include the following:
      • Girls
        • Ovarian tumors such as Leydig cell tumors or granulosa cell tumors
        • Ovarian cyst
      • Boys
        • Germ cell tumors secreting hCG
        • Leydig cell tumors
        • Familial male-limited precocious puberty or testotoxicosis caused by an activation mutation of the LH-receptor gene
      • Both boys and girls
        • Adrenal androgen production due to adrenocorticotropic hormone (ACTH) stimulation: congenital adrenal hyperplasia, 21-hydroxylase deficiency, 11-β-hydroxylase deficiency
        • McCune-Albright syndrome: a triad of precocious puberty, café au lait skin pigmentation, and fibrous dysplasia of the bone
        • Excess exogenous estrogen exposure from creams, sprays, or ointments
  • Incomplete precocious puberty (1)
    • A variant of normal puberty
    • Presents with early development of secondary sexual characteristics
  • Premature thelarche
    • Can occur in two peaks: during the first 2 years of life and between ages 6 and 8 years
    • More common in black and Hispanic children
    • 14–20% of children affected can develop true precocious puberty.
    • Characterized by
      • Development of isolated unilateral or bilateral breasts
      • Absence of other sexual characteristics
      • Normal linear growth and normal bone age
      • Sex hormone levels are in the prepubertal range.
  • Premature adrenarche
    • Characterized by the appearance of pubic and/or axillary hair, acne, and adult body odor before the age of 8 years in girls and 9 years in boys
    • Normal linear growth and bone age
    • Common in girls and individuals with insulin resistance and obesity
    • 20% of girls affected can develop polycystic ovarian syndrome as adults.
    • Most cases are idiopathic but may be caused by congenital adrenal hyperplasia, 21-hydroxylase deficiency, Cushing disease, dehydroepiandrosterone sulfate (DHEA-S) deficiency, autonomous endogenous or exogenous excess.

General Prevention

Precocious puberty is not preventable, but early detection is helpful, so the following steps are recommended:

  • Careful growth chart review
  • Thorough physical exam for early signs of puberty
  • Anticipatory guidance in late childhood should include normal pubertal development.

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