Isolated scrotal hair in infancy.

Nine male infants who developed scrotal hair with no other signs of virilization were evaluated. Median age for the development of scrotal hair was 4.5 months, and median age at presentation was 7.5 months. Endocrinologic investigations performed in 6 of the infants yielded normal findings. The scrotal hair receded at a mean age of 12 months, suggesting a transient benign event. The development of genital hair in boys under age 9 years is considered precocious, suggesting a possible pathological condition (eg, precocious puberty, congenital adrenal hyperplasia, adrenal or genital tumors), or may be due to premature adrenarche.