title: African hair length in a school population: a clue to disease pathogenesis?
abstract: BACKGROUND
  Anecdotal data suggest that combed natural African hair reaches a length steady state. Easier grooming and anticipated long hair have made relaxers popular.
  
  
  OBJECTIVE
  These hypotheses were tested in a cross-sectional survey of 1042 school children using a piloted questionnaire and hair length measurements done on four scalp regions.
  
  
  RESULTS
  Participants included 45% boys and 55% girls. Girls consider length important for hairstyle choice (P < 0.0001). There was no difference in mean length at 2 to 5 vs. > 5 years (P = 0.3) and at 1 to < 2 vs. 2 to 5 years (P = 0.99), suggesting that a steady state is reached within 1 year after a hair cut for combed natural hair [mean, 5.1 cm (4.3)]. Relaxed hair reached length steady state > 2 years after a haircut [mean, 10.9 cm (3.6)], was longer than natural hair (P < 0.0001), shorter than expected, and significantly shorter on the occiput than the rest of the scalp (P < 0.0001).
  
  
  CONCLUSIONS
  Persistently short combed natural hair years after a hair cut suggests that breakage eventually equals new growth (i.e., steady state), which is likely to be variable. Relaxed hair, irrespective of last haircut, is also short; chemical damage as a limit to potential lengths needs confirmation. Relatively short occipital relaxed hair could be a clue to disease pathogenesis.
authors.affiliation: Division of Dermatology, Groote Schuur Hospital, South Africa. nonhlanhla.khumalo@uct.ac.za
authors.forename: N P
authors.initials: NP
authors.lastname: Khumalo
authors.forename: F
authors.initials: F
authors.lastname: Gumedze
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D044383:Black People; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006197:Hair / Q000033:anatomy & histology / Q000187:drug effects / Q000254:growth & development*; D006201:Hair Diseases / Q000139:chemically induced / Q000208:ethnology; D006203:Hair Preparations / Q000009:adverse effects / Q000494:pharmacology*; D006801:Humans; D006920:Hygiene; D008297:Male; D008855:Microscopy, Electron, Scanning; D012535:Scalp / Q000033:anatomy & histology; D012737:Sex Factors; D013019:South Africa; D011795:Surveys and Questionnaires
chemical_list: D006203:Hair Preparations