Delayed telogen replacement in a boy's scalp

Background: In case the shedding telogen hair is not replaced in time by a terminal anagen hair, an empty space results. Objective: To verify whether the phenomenon is present in prepubertal subjects. Methods: From July 1996 to May 1997, an 8-year-old boy was submitted monthly to the phototrichogram technique. Sixty hairs were monitored throughout the study. Results: 52% o f all studied hairs were terminal anagen hairs throughout the study and add itionally 22% were in a regular hair cycle. Vellus hairs and empty spaces w ere observed in 18 and 8% of follicles, respectively. In 2% of hairs, vellu s hairs and empty spaces were associated. Conclusions: Vellus hairs and emp ty spaces are present even in children. Without gonadal androgens and expre ssion or induction of Sa-reductase in the prepubertal scalp, they are unlik ely to herald androgenetic alopecia (AGA) but could reflect a physiological phenomenon of 'true resting' of a small proportion of scalp hair. Androgen s may increase the phenomenon which may account in part for AGA development .