Endocrine Abstracts

Background: Premature pubic hair development, with or without manifestations of androgen production, is a common clinical presentation. Premature adrenarche (PA) needs to be differentially diagnosed from congenital adrenal hyperplasia (CAH) and may be associated with early development of puberty.

Aim: To study the characteristics at presentation, endocrine profile and outcome of patients who presented with premature pubic hair development. We studied retrospectively case notes of 64 patients [49 female (76.6%), 15 male (23.4%)] who have been referred for investigation over the last five years.

Results: Patients presented at a mean age of 7.2±2.09 years with a mean height SDS of 1.57±1.35 (range −1.62–5.22). Apart from premature development of pubic hair, other symptoms included increased body odour (50.0%), acneiform changes (25.0%), accelerated growth (18.8%) and mood changes (10.9%). PA was confirmed in 79.7% (n=51), virilising CAH due to CYP21 mutations was diagnosed in 14.1% (n=9) and CAH due to CYP11B1 mutations in 6.2% (n=4). Children with CAH were taller at presentation compared to those with PA (height SDS 2.5±1.4 vs 1.3±1.2, P<0.05) but there was no significant difference in the age, weight or BMI SDS at presentation. Compared to children diagnosed with PA, those with CAH had significantly higher DHEAS (4.5±2.5 vs 2.6±1.6 μmol/l), A4 (11.8±10.9 vs 2.9±1.9 nmol/l) and testosterone (2.27±2.3 vs 0.79±0.24 nmol/l). ROC curve analysis showed that a basal 17OHP greater than 4.9 nmol/l has a 77% sensitivity and 95.8% specificity in diagnosing CAH. Although long term data are not complete, 9.8% of patients with PA developed early puberty and in 3.9% there was evidence of PCOS on ultrasound.

Conclusion: The increased percentage of CAH may result from selection bias. Although rare, CAH due to CYP11B1 mutations should be suspected. Long term follow up will elucidate the natural history of PA.