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Precocious and delayed puberty
Precocious puberty is the appearance of secondary sexual characteristics before age 8 in a girl or age 9 in a boy; the first question is whether it is central (GnRH-dependent) or peripheral, and the second — whether it is a benign variant at all.
Why it matters in the exam
Questions present a 7-year-old girl with breast development and a growth spurt, or a 6-year-old boy with pubic hair. The candidate must know that central precocious puberty in girls is usually idiopathic, whereas in boys there is often a structural cause, so a brain MRI is mandatory. The treatment of central puberty is a GnRH analogue. In peripheral puberty, look for CAH, tumours, McCune-Albright syndrome and hormone exposure (a parent's testosterone gel).
It is important to recognise benign variants that need no treatment: isolated breast development in toddlers (premature thelarche) — without a growth spurt and with a normal bone age; and isolated pubic hair or body odour (premature adrenarche) with a mildly raised DHEAS. Delayed puberty is the absence of breast development by 13 in girls or of testicular enlargement by 14 in boys; the common cause is constitutional delay, but Turner, Klinefelter and Kallmann (with a disordered sense of smell) must be excluded.
Key points
- Precocious: girls before 8, boys before 9.
- Central: raised LH, treated with a GnRH analogue; MRI always in boys.
- Peripheral: suppressed LH and FSH; CAH, tumours, McCune-Albright, exogenous hormones.
- Benign variants: premature thelarche and premature adrenarche, without a growth spurt.
- Delayed: no breasts by 13 or no testicular enlargement by 14; the common cause — constitutional delay.
Summary table
| Condition | Definition or feature | Tests | Treatment |
|---|---|---|---|
| Central precocious puberty | Before age 8 (girls) or 9 (boys), normal pubertal sequence, growth spurt | Raised basal LH or a high stimulated LH; advanced bone age; MRI | GnRH analogue |
| Peripheral precocious puberty | Suppressed LH and FSH | 17-OHP (CAH), hCG, ovarian and adrenal ultrasound | Treat the cause |
| McCune-Albright | Irregular café-au-lait spots, fibrous dysplasia of bone, peripheral precocious puberty | Skeletal imaging | Treat the cause and endocrine follow-up |
| Premature thelarche | Breasts only, usually under 2, no growth spurt | Normal bone age | Follow-up |
| Premature adrenarche | Pubic hair or body odour only | Mildly raised DHEAS, near-normal bone age | Follow-up |
| Delayed puberty | No breasts by 13 (girls) or no testicular enlargement by 14 (boys) | LH, FSH, karyotype, sense of smell | By cause; constitutional delay — follow-up or a short hormonal course |
Free exam questions
בת 6 חדשים אשר ניזונה מהנקה, הופנתה למרפאה בשל הגדלת שד חד צדדית, ללא תשעורת מינית, ללא הפרשה נרתיקית. צילום כף יד לגיל עצמות.תואם גיל כרונולוגי מה האבחנה הסבירה ביותר? (the question as examined, in Hebrew)
- א. Premature telarche
- ב. Central precocious puberty
- ג. Ovarian tumor
- ד. Estrogens from mother's breast milk
A 16-year-old girl, with overweight and hirsutism, complains of irregular menstruation. Investigation that included prolactin levels, thyroid function, ACTH test, and urine collection for cortisol was normal. Which of the following findings would support the most likely diagnosis?
- A. Multiple follicles in the ovaries on an US
- B. Low levels of androstenedione in the blood
- C. Low LH levels relative to FSH levels in the blood
- D. Low levels of estrogen in the blood
In the full version for subscribers
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Sources
- Nelson Textbook of Pediatrics, 22nd edition (2024) — Disorders of Pubertal Development
- Endocrine Society and Pediatric Endocrine Society consensus: Use of GnRH analogs in children, 2009, with the international update 2019 — Central precocious puberty
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.