4 - Endocrine disorders

Summary

Puberty is a dynamic continuum with the first signs in girls appearing at around the age of 9 years (see Chapter 1). Pubertal development that occurs before the age of 8 years is considered to be precocious. Precocious puberty occurs twelve times more commonly in girls than in boys. It may be central, in which there is premature activation of the hypothalamic—pituitary—ovarian axis or it may occur independent of the axis, in which case it is referred to as pseudopuberty or pseudosexual precocity.

Central precocious puberty

Central precocious puberty is also more common in females than in males by a factor of 23. In girls, most causes are idiopathic. Causes identified include brain abnormalities, such as hydrocephalus, tumours (particularly hamartomas), congenital abnormalities, trauma and infections. Hamartomas may cause precocious puberty at an extremely early age, even as early as the neonatal period. Precocious puberty is also associated with a wide variety of diverse conditions including neurofibromatosis, tuberous sclerosis and hypothyroidism. Hypothyroidism is particularly likely to be the diagnosis if the girl's pubertal development occurs without the accompanying growth spurt.

Because of the association with underlying brain pathology, it is recommended that all girls with precocious puberty have brain imaging performed with either computed tomography or, preferably, magnetic resonance imaging, even in the absence of neurological symptoms or signs, as the abnormality may be small.

Girls with central precocious puberty undergo a normal sequence of pubertal development.