A 7-year-old girl is brought with pubic hair development (Tanner stage 2) for 3 months. Breast development is absent. Bone age is 8 years. Serum DHEAS is elevated; LH/FSH are prepubertal. She is otherwise healthy with normal height velocity. The MOST likely diagnosis is:

• A Central (true) precocious puberty — gonadotropin-dependent
• B Non-classical congenital adrenal hyperplasia (late-onset 21-OHD)
• C Exogenous androgen exposure (e.g., from topical steroid cream)
• D Premature pubarche due to early adrenarche — a benign variant ✓

Explanation

Premature pubarche (isolated pubic/axillary hair before age 8 in girls) is most commonly caused by premature adrenarche — early activation of adrenal androgen (DHEAS) production without gonadotropin axis activation. Key features that support benign premature adrenarche: isolated pubic hair without breast development, prepubertal LH/FSH, mildly elevated DHEAS for age, bone age slightly advanced but <2 years ahead, and normal height velocity. Non-classical CAH can mimic this but typically shows more markedly elevated DHEAS and 17-OHP after ACTH stimulation. Central precocious puberty involves gonadotropin-driven breast and pubic hair development together. Isolated pubarche requires monitoring but is usually benign.

Reference: Ghai Essential Pediatrics, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.