Are pubertal changes in girls before age 8 benign?

Objective. The Lawson Wilkins Pediatric Endocrine Society recently issued new recommendations for the age at which puberty should be considered precocious, lowering the prevailing standards from 8 years to 7 years for white girls and to 6 years for black girls. The new recommendations were based on a single epidemiologic study that focused on the conditions of premature thelarche and premature adrenarche (both characterized by a single sign of puberty). Although the data were available, the authors did not comment on the low incidence of true precocious puberty (characterized by breast and pubic hair development) in their population. The hypothesis for the present study is that the new recommendations lead to underdiagnosis of endocrine pathology. Methods. Using 29 International Classification of Diseases, Ninth Revision codes for diagnoses known to be associated with precocious puberty, we identified 1570 patient visits to our outpatient pediatric endocrinology clinic of white girls aged 7 to 8 and black girls aged 6 to 8 during a 5-year period. Results. Of the 1570 patient visits, 223 unique patients were identified as having been referred for the sole finding of precocious pubertal development. These 223 patients carried no other endocrine diagnoses. Eleven patients (4.9%) were found to have no true breast buds and no terminally differentiated pubic hair. A total of 105 (47.1%) of 223 patients were found to have 2 signs of puberty, consistent with true precocious puberty according to the conventional guidelines of precocity of 8 years in girls. Overall, 12.3% of patients also had diagnoses of other endocrine conditions that included congenital adrenal hyperplasia, McCune-Albright syndrome, growth hormone deficiency, hypothyroidism, hyperinsulinism, pituitary adenoma, and neurofibromatosis. A total of 35.2% of girls with true precocious puberty exhibited bone ages >3 standard deviations above the mean, indicating markedly diminished growth potential. Conclusions. We conclude that signs of puberty in 6- to 8-year-old girls should not be considered normal or benign. Implementation of the new guidelines for the evaluation of puberty will result in failure to identify conditions that respond to early intervention.