title: Delayed telogen replacement in a boy's scalp.
abstract: 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% of all studied hairs were terminal anagen hairs throughout the study and additionally 22% were in a regular hair cycle. Vellus hairs and empty spaces were observed in 18 and 8% of follicles, respectively. In 2% of hairs, vellus hairs and empty spaces were associated.
  
  
  CONCLUSIONS
  Vellus hairs and empty spaces are present even in children. Without gonadal androgens and expression or induction of 5alpha-reductase in the prepubertal scalp, they are unlikely to herald androgenetic alopecia (AGA) but could reflect a physiological phenomenon of 'true resting' of a small proportion of scalp hair. Androgens may increase the phenomenon which may account in part for AGA development.
authors.affiliation: Department of Dermatology, University of Genoa, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Guarrera
authors.forename: C
authors.initials: C
authors.lastname: Cipriani
authors.forename: A
authors.initials: A
authors.lastname: Rebora
mesh_terms: D000505:Alopecia / Q000097:blood / Q000473:pathology / Q000503:physiopathology*; D000728:Androgens / Q000097:blood; D002648:Child; D018859:Hair Follicle / Q000254:growth & development* / Q000473:pathology; D006801:Humans; D008297:Male; D012536:Scalp Dermatoses / Q000097:blood / Q000473:pathology / Q000503:physiopathology*
chemical_list: D000728:Androgens