OG23.3 | Precocious Puberty — Summary & Reflection

KEY TAKEAWAYS

Precocious puberty: secondary sex characteristics before age 8 in girls. Classified as central (GnRH-dependent, HPO axis activated — LH/FSH elevated, GnRH stimulation test positive; 80–90% idiopathic in girls; pathological: hypothalamic hamartoma most common, then CNS tumours) or peripheral (GnRH-independent, autonomous sex steroids — LH/FSH suppressed; causes: McCune-Albright syndrome, granulosa cell tumour, CAH, exogenous steroids). Benign variants: premature thelarche (isolated breast bud, normal bone age, prepubertal gonadotrophins) and premature adrenarche (isolated pubic hair, adrenal DHEAS-driven) — both benign, monitor only. Investigation: bone age + basal LH/FSH → GnRH stimulation test (central if LH peak >5–8 IU/L, LH:FSH >1) → brain MRI for central; pelvic ultrasound + steroid profile for peripheral. Management: GnRH analogues (leuprolide, triptorelin depot) for central PP — suppress HPO axis, preserve adult height; cause-directed for peripheral (aromatase inhibitor/McCune-Albright; surgery/granulosa tumour; hydrocortisone/CAH). Brain MRI is mandatory in all confirmed central PP even if likely idiopathic.

REFLECT

A 7-year-old girl's parents are told their daughter has idiopathic central precocious puberty and needs monthly injections for the next 3–4 years. How do you explain this diagnosis, its implications, and the treatment to parents in a way that is reassuring but accurate? What are their likely concerns about monthly injections, fertility, and adult height — and how would you address each? Reflect on the ethical dimension of treating a condition that, if left alone, would 'resolve' at menarche but with a permanent cost to adult height.