title: Prevalence of acne keloidalis nuchae in football players.
abstract: BACKGROUND
  Acne mechanica (AM) is common in football players. Severe cases of nuchal AM may precede acne keloidalis nuchae (AKN). Factors that may be associated with the progression of nuchal AM to AKN are unknown. The prevalence of AKN in football players has not been reported.
  
  
  OBJECTIVE
  We investigated the frequency of nuchal AM and AKN within a susceptible population and attempted to identify factors that may be associated with AKN.
  
  
  METHODS
  Four hundred fifty-three high school, collegiate, and professional football players were examined for the presence of nuchal AM or AKN. Those with positive findings completed a questionnaire regarding their disease.
  
  
  RESULTS
  Nuchal AM was more prevalent in high school players (15.5%) than older players (1.2%). AKN was more frequent in players beyond the high school level and was found exclusively in blacks. AKN was not associated with a positive family history of AKN nor a positive personal or family history of keloid formation.
  
  
  CONCLUSIONS
  AKN occurs almost exclusively in blacks. The level of football play may be associated with the development of AKN. Positive family history of AKN and positive family or personal history of keloids is not associated with AKN development.
authors.affiliation: Department of Dermatology, Indiana University, Indianapolis, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Knable
authors.forename: C W
authors.initials: CW
authors.lastname: Hanke
authors.forename: R
authors.initials: R
authors.lastname: Gonin
mesh_terms: D000153:Acne Keloid / Q000453:epidemiology* / Q000235:genetics; D000152:Acne Vulgaris / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D044383:Black People; D016001:Confidence Intervals; D018450:Disease Progression; D004198:Disease Susceptibility; D005538:Football / Q000706:statistics & numerical data*; D006801:Humans; D007196:Indiana / Q000453:epidemiology; D007627:Keloid / Q000453:epidemiology / Q000235:genetics; D016015:Logistic Models; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012536:Scalp Dermatoses / Q000453:epidemiology* / Q000235:genetics; D011795:Surveys and Questionnaires; D044465:White People; D001741:Black or African American