title: Melanocytic nevus development in Colorado children born in 1998: a longitudinal study.
abstract: OBJECTIVE
  To describe the development of nevi from 3 to 8 years of age in a birth cohort of children in Colorado.
  
  
  METHODS
  Longitudinal observational study.
  
  
  METHODS
  Large managed care organization and university and private primary care practices.
  
  
  METHODS
  Annual convenience samples of children born in 1998 (range, n = 137 to n = 870) (participation rates, 18.8%-76.0%). We recruited children through the managed care organization, private primary care practices, and community settings.
  
  
  METHODS
  Total whole body nevus counts, counts by nevus diameter (< 2, 2 to < 5, or > or = 5 mm), and counts for chronically and intermittently exposed body sites.
  
  
  RESULTS
  Non-Hispanic white children had significantly more nevi than did other racial/ethnic groups and developed an average of 4 to 6 new nevi per year from 3 to 8 years of age. Non-Hispanic white boys had significantly more nevi than did girls beginning at 6 years of age (median, 21 [interquartile range, 28] vs 17 [17]; P = .002). This difference was due to nevi of less than 2 mm and nevi in chronically exposed body sites. Development of new nevi leveled off in chronically exposed body sites at 7 years of age and at a higher level for boys than girls.
  
  
  CONCLUSIONS
  Children in Colorado developed more small nevi and fewer large nevi compared with children in other regions of the world, highlighting the importance of studying nevus development in various locations where sun exposure patterns and behavioral norms vary. The sex difference in nevus development could be owing to variation in sun exposure and/or a biological predisposition of boys to develop more nevi. Studies of nevus development can aid in the understanding of the complicated relationship between nevus development and malignant melanoma.
authors.affiliation: Department of Community and Behavioral Health, Colorado School of Public Health, University of Colorado Denver, 13001 E 17th Pl, Campus Box B119, Aurora, CO 80045, USA. lori.crane@ucdenver.edu
authors.forename: Lori A
authors.initials: LA
authors.lastname: Crane
authors.forename: Stefan T
authors.initials: ST
authors.lastname: Mokrohisky
authors.forename: Robert P
authors.initials: RP
authors.lastname: Dellavalle
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Asdigian
authors.forename: Jenny
authors.initials: J
authors.lastname: Aalborg
authors.forename: Tim E
authors.initials: TE
authors.lastname: Byers
authors.forename: Chan
authors.initials: C
authors.lastname: Zeng
authors.forename: Anna E
authors.initials: AE
authors.lastname: Barón
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Burch
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Morelli
mesh_terms: D002648:Child; D002675:Child, Preschool; D003120:Colorado / Q000453:epidemiology; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data; D008137:Longitudinal Studies; D008297:Male; D009508:Nevus, Pigmented / Q000453:epidemiology* / Q000473:pathology*; D010858:Pigmentation; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D044465:White People / Q000706:statistics & numerical data