Precocious Puberty

Precocious Puberty

There are many causes of precocious sexual development and these are probably best categorised into those that are gonadotrophin dependent and independent (table 1). Such a classification helps both in understanding the aetiology the condition, and also in deciding the treatment options. In central precocious puberty, the most characteristic feature is maintenance of the harmony (consonance) of normal puberty. Thus, there is breast and pubic hair development, and a growth acceleration, which all occur in exactly the same sequence of events as in normal puberty, with the exception that this occurs at an earlier age. In all the other variants of premature sexual maturation, this harmony of normal puberty is lost, namely early vaginal bleeding with minimal breast development in McCune-Albright syndrome or breast development in the absence of a growth spurt in premature thelarche.

In the older nomenclature, children with central precocious puberty were described as having 'complete' precocious puberty, whereas those with other variants of sexual maturation were called 'partial' or 'incomplete' precocious puberty.

Central precocious puberty is also known as 'idiopathic' precocious puberty or gonadotrophin-dependent precocious puberty. The cut-off age for the definition of precocious puberty is 8 years; precocious sexual maturation in a girl under 8 years of age is called precocious.

Table 1. Classification of disorders of premature sexual maturation of a gonadal aetiology Gonadotrophin dependent Central precocious puberty Idiopathic Hypothalamic tumours/cysts Low dose cranial irradiation Primary hypothyroidism with elevated FSH secretion Tumours producing β-hCG secretion (e.g. hepatic tumours) in boys

Gonadotrophin independent
Testotoxicosis in boys
McCune-Albright syndrome in girls
Hypomelanosis of Ito in girls
Premature thelarche
Premature thelarche variant (also called slowly progressive precocious puberty or exaggerated thelarche)
Isolated menarche