RESUMEN
Twenty-two prepubertal girls with hypertrichosis were studied and compared to 10 prepubertal normal girls. Hypertrichosis was assessed according to a score that considers the amount and the distribution of vellus hair in androgen- and non-androgen-sensitive areas. Serum androgen profile and free androgen index (FAI) were determined in both groups. The hypertrichosis score was higher in patients than in the normal girls. Testosterone levels and FAI were increased in patients when compared to control; 3alpha-androstanediol glucuronide levels above 2 SD from the control mean were found in 10 girls and all hormonal parameters falling in the normal range were found in 4 girls. The new score designed to assess the degree of hypertrichosis was useful to differentiate between normal and pathological hair growth. Although most of the girls with prepubertal hypertrichosis showed an increased androgen bio-availability, a slight increase in peripheral 5alpha-reductase activity and a completely normal androgen profile was also associated with a pathological hair growth.