Precocious puberty A case Dóra Török MD, PhD

Parents bring their 5-year-old daughter to your clinic because she has developed breast and pubic hair over the past 3 months. Physical examination reveals a girl whose height and weight are above the 95th percentile, Tanner stage II breast and pubic hair development, oily skin, and facial acne.

Parents bring their 5-year-old daughter to your clinic because she has developed breast and pubic hair over the past 3 months. Physical examination reveals a girl whose height and weight are above the 95th percentile, Tanner stage II breast and pubic hair development, oily skin, and facial acne. * What is the most likely diagnosis? * What is the best next step in the evaluation?

* Most likely diagnosis: Idiopathic central precocious puberty. * Next step in the evaluation: Inquire about birth history, illnesses, hospitalizations, medications, siblings’ health status, and family history of early puberty and diseases. Serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels and bone age radiographs are helpful.

DELAYED PUBERTY: No signs of puberty in girls by age 13 years or in boys by age 14 years. May be caused by gonadal failure, chromosomal abnormalities (Turner syndrome, Klinefelter syndrome), hypopituitarism, chronic disease, or malnutrition. CLINICAL CASES 249 PRECOCIOUS PUBERTY: Secondary sexual characteristic onset before age 8 years in girls and 9 years in boys. Children in different ethnic groups undergo puberty differently; African-American girls often do so earlier than Caucasian girls. TRUE (CENTRAL) PRECOCIOUS PUBERTY: Gonadotropin-dependent. Hypothalamic-pituitary-gonadal activation leading to secondary sex characteristics. PRECOCIOUS PSEUDOPUBERTY: Gonadotropin-independent. No hypothalamic-pituitary-gonadal activation. Hormones usually are either exogenous (birth control pills, estrogen creams) or from adrenal/ovarian tumors. PREMATURE ADRENARCHE: Early activation of adrenal androgens (typically in girls ages 6 to 8 years), with gradually increasing pubic/axillary hair development and body odor. PREMATURE THELARCHE: Early breast development (typically in girls ages 1 to 4 years), without pubic/axillary hair development or linear growth acceleration.

Bone age

More common in girls, true precocious puberty stems from secretion of hypothalamic GnRH with normal-appearing, but early, progression of pubertal events. Sexual precocity is idiopathic in more than 90% of girls, whereas a structural CNS abnormality is present in 25% to 75% of boys.

GnRH stimulation LH peak in puberty (3-10x) FSH peak in prepuberty (3-5x) Therapy: monthly GnRH Depot injection