EndocrinologyTier 2Disease (DEADMAN)

Precocious puberty

Description

Precocious puberty (pubertal onset before an age threshold below the population norm - conventionally before age 8 in girls and 9 in boys) is classified as central (gonadotrophin-dependent, true premature activation of the hypothalamic-pituitary-gonadal axis) or peripheral (gonadotrophin-independent, from an autonomous source of sex hormone outside normal axis control) - this distinction fundamentally changes both investigation and treatment

More common in girls than boys, with central precocious puberty being idiopathic in the large majority of girls but more frequently associated with an identifiable underlying cause (structural CNS lesion) in boys, making the threshold for neuroimaging lower in male presentations

Central precocious puberty reflects premature, but otherwise normally sequenced, activation of the hypothalamic-pituitary-gonadal axis (elevated gonadotrophins) - idiopathic in most girls, but with a meaningfully higher likelihood of an underlying structural hypothalamic/pituitary lesion in boys or in girls with additional atypical features
Peripheral precocious puberty arises from autonomous sex hormone production independent of gonadotrophin drive (e.g. an ovarian/testicular/adrenal tumour, McCune-Albright syndrome, or exogenous hormone exposure) - gonadotrophins are characteristically suppressed given the autonomous hormone source's negative feedback on the axis

Gonadotrophin levels (basal or GnRH-stimulated) are the key discriminating test - elevated/pubertal-range gonadotrophins support central precocious puberty, while suppressed gonadotrophins with elevated sex hormone support a peripheral cause
Neuroimaging (MRI brain/pituitary) is indicated for confirmed central precocious puberty, particularly in boys (higher structural lesion likelihood) or with any atypical/rapidly progressive features, to exclude an underlying CNS lesion

Central precocious puberty: GnRH agonist therapy suppresses the prematurely activated axis, halting further pubertal progression and preserving growth potential/final adult height, alongside treatment of any identified underlying structural cause
Peripheral precocious puberty: treatment targets the specific autonomous hormone source (e.g. tumour resection, or specific medical therapy for McCune-Albright syndrome)

Central vs peripheral distinction (gonadotrophin level as the key discriminator), sex difference in idiopathic vs structural cause likelihood, final adult height preservation as a treatment goal, McCune-Albright syndrome (peripheral cause with characteristic additional features)

Central precocious puberty in boys has a meaningfully higher likelihood of an underlying structural CNS lesion than in girls (where idiopathic disease dominates) - this sex difference lowers the threshold for neuroimaging in male presentations, even when the clinical picture otherwise appears straightforward

6 more sections, plus exam facts

Premium unlocks every note across every specialty, and the full exam fact library behind it.