Definition (Pediatrics 1999;104:936; Pediatr Ann 2006;35:916)
• Girls w/ thelarche (breast dev) or pubarche (pubic hair) before 7 yo in obese & before 8 yo in non-obese need eval. Obesity inc risk of early puberty in girls
• Girls w/ pubarche and no thelarche <8 yo usually dx’d w/ benign premature adrenarche
• Further eval if evid ↑ androgen (linear growth accelerated, clitoral enlargement, acne)—bone age >1–2 yr advanced looks for late-onset CAH
• Girls w/ thelarche after 7 yo need eval if:
• Rapid progression of puberty w/ adv bone age (>2 yr above chrono age) and/or predicted adult ht >2 SD below genetic target ht (father’s ht + mother’s ht − 5)/2)
• New CNS symptoms (headache, seizure, or focal neurologic deficits, underlying CNS disease including hydrocephalus, behavioral concerns)
• Boys <9 yo w/ signs of puberty other than pubic hair (e.g., penile and scrotal enlargement, acne, growth acceleration) w/ or w/o testicular enlargement need eval—if only hair, likely premature adrenarche and only bone age is needed
Pathophysiology
• In girls, breast tissue dev (thelarche) 1st signs of activation of pituitary–gonadal axis, testicular enlargement (gonadarche) in boys; pubic hair development (adrenarche) results from adrenal androgen production, different axis
• May be gonadotropin-releasing hormone (GnRH) dependent or independent
Etiology
• Majority of girls, central precocious puberty (CPP) is idiopathic
• Significant proportion of boys w/ CPP will have CNS disease
• Also consider obesity (girls), gonadal tumors, other sources of sex steroids
Diagnostic Evaluation
• Labs: Bone age, testosterone (males), estradiol (females), 8 am 17-OH progesterone, LH/FSH, hCG, DHEAS, and DHEA. GnRH stim test
• Eval may also include TFTs, MRI brain (depends on H&P)
• Consider exogenous exposure to estrogen/androgens
Complications
• Precoc puberty may cause bone age accel, premat growth plate closure & ↓ adult ht
• In girls w/ idiopathic CPP, puberty may be longer, thus adult height not significantly adversely affected (slowly progressive precoc puberty)
Therapy
• Rx w/ GnRH-agonists (inhibit gonadotropin and sex steroid secretion) may improve adult height. Benefit to height greatest if Rx started before 8 yo