Endocrine Abstracts (2013) 32 P796 | DOI: 10.1530/endoabs.32.P796

Premature pubarche: distinguishing between nonclassic congenital adrenal hyperplasia and idiopathic premature adrenarche

Ester Pereira, Joana Caetano, Rita Cardoso, Sara Ferreira, Sónia Santos, Marta Ferreira, Beatriz Vale, Isabel Dinis & Alice Mirante

Unit of Endocrinology, Diabetes and Growth, Hospital Pediátrico do Centro Hospitalar e Universitário de Coimbra, EPE, Coimbra, Portugal.

Introduction: Premature pubarche (PP) is most often related to idiopathic premature adrenarche (IPA). However, it is a diagnosis of exclusion and differential diagnosis must include milder and nonclassic variants of congenital adrenal hyperplasia (CAH).

Purpose: To identify clinical predictors of CAH and IPA in children with PP.

Materials and methods: A retrospective study was conducted including children seen for PP between 2001 and 2011 with baseline blood sampling for DHEAS, androstenedione, 17OHP and free testosterone and a follow up of at least 1 year. Patients were considered to have CAH if their 17OHP level was ≥2.0 ng/ml and CAH was confirmed by mutational analysis of the CYP21 gene. Exclusion criteria were: neonatal onset, concomitant clinical signs of central puberty and genetic syndromes. Statistical analysis was done using SPSS 19th (P<0.05).

Results: Fifty-three children with PP were included: 6 had CAH (11.3%) and 47 were classified as IPA (88.7%). Pubic hair onset was reported by the parents at 4.9 ±2.2 and 4.9±1.6 years (P=0.940) and age at the first appointment was 7.1±1.0 years and 6.9±1.5 (P=0.692) in CAH and IPA respectively. There was no difference on stature SDS and BMI–SDS at the first appointment and after one year. Progression of pubic hair Tanner stage in the first year also didn’t differ between the two groups. Growth velocity SDS was 1.34±0.76 in CAH and 0.75±1.06 in IPA (P=0.195). Bone age was advanced 1.9±1.3 years in CAH and 1.1±1.3 years in IPA (P=0.175). Besides 17OHP, also free testosterone was higher in the CAH group (P=0.005).

Conclusions: CAH cannot be distinguished from IPA on a clinical basis. Evaluation of androgens is essential to make the differential diagnosis in a child with PP.