Introduction:
Precocious puberty in girls is defined as the development of secondary sexual characteristics before 8 years of age. Early puberty can be a normal variant or indicate an underlying pathological cause. Timely diagnosis is crucial to prevent compromised adult height and identify treatable conditions like CNS lesions or hormone-secreting tumors.
Clinical Evaluation: Recognizing the Early Signs
Breast development (Thelarche) before 8 years
Pubic/axillary hair (Pubarche) before 8 years
Menarche before 9.5 years
Growth spurt (often missed unless plotted properly)
Acne or body odor
Types of Precocious Puberty
Central (Gonadotropin-dependent): Early activation of the hypothalamic-pituitary-gonadal (HPG) axis
Peripheral (Gonadotropin-independent): Excess sex hormones from adrenal, gonadal, or exogenous sources
Variants: Premature thelarche or adrenarche (often benign)
Step-by-Step Diagnostic Approach
1. History & Physical Exam
Onset and progression of symptoms
Neurological symptoms: headache, seizures (suggest CNS pathology)
Family history
Height and weight velocity
Tanner staging
2. Bone Age Assessment
X-ray of the left hand and wrist
Advanced bone age supports true puberty
Normal bone age suggests benign variant
3. Hormonal Tests
Basal LH, FSH, and Estradiol:
LH >0.3–0.6 IU/L is suggestive of central puberty
GnRH Stimulation Test (if needed):
Peak LH >5–8 IU/L confirms central puberty
DHEAS, 17-OHP, Testosterone: For peripheral causes
TSH, Prolactin: Rule out hypothyroidism and prolactinomas
4. Imaging Studies
MRI Brain: In all girls <6 years or with neurological signs (rule out hypothalamic hamartoma, glioma, etc.)
Pelvic Ultrasound: Assess uterine and ovarian size/morphology
Adrenal Imaging: If suspecting adrenal tumor or CAH
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Red Flags Indicating Pathological Puberty
Onset before 6 years
Rapid progression of puberty
Neurological signs
Very high hormone levels
Androgenic features (e.g., clitoromegaly)
