Precocious puberty

Puberty occurring before the age of 8 years in girls and 9 years in boys in considered precocious. The numerous causes of precocity can be classified as central or peripheral. Central or true precocious puberty (CPP) is due to premature activation of the hypothalamopituitary-gonadal axis and is isosexual. Peripheral or pseudoprecocious puberty (PPP) results from the production of sex steroids independent of the H-P-G axis and may be isosexual or heterosexual. CPP is the most common form of precocity involving more than 50% of children and is much more common in girls than boys. CPP is more common between 4 and 8 years. A peak serum LH levels > 10 iu/l following GnRH stimulation is the absolute evidence of CPP. Serum IGF-I levels are predictive of the outcome. Availability of CT and MRI has helped to determine the cause of CPP in most cases. Hypothalamic hamartoma is the most common tumour causing CPP especially in boys. Adrenal causes, particularly CAH, are the commonest cause of PPP in boys whereas ovarian causes are more likely in girls. Long acting GnRH analogues provide a safe and effective form of treatment of CPP.