title: Computer-assisted alignment and tracking of acne lesions indicate that most inflammatory lesions arise from comedones and de novo.
abstract: BACKGROUND
  Inflammatory acne lesions are believed to derive from comedones; however, their evolution has not been rigorously studied.
  
  
  OBJECTIVE
  To examine the evolution of facial acne lesions using serial digital photographs and spatial alignment software.
  
  
  METHODS
  Six predefined lesion types, including inflammatory lesions, were counted and tracked from photographs taken every 2 weeks for 12 weeks from 25 individuals with untreated facial acne.
  
  
  RESULTS
  Closed comedones occurred most frequently (37%), followed by erythematous macules (26%), inflammatory papules (15%), open comedones (12%), pustules (2%), and nodules (1%). Inflammatory lesions were preceded by comedones (54%), normal-appearing skin (28%), erythematous macules (12%), and scars (6%).
  
  
  CONCLUSIONS
  Lesions could have appeared and resolved within the 2-week intervals and some comedones may have been too small to identify on digital photographs.
  
  
  CONCLUSIONS
  Our results confirm the comedonal origin of the majority of inflammatory acne lesions. However, a sizeable number (28%) appear to arise from normal skin.
authors.affiliation: Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA. thythydo@med.umich.edu
authors.forename: Thy Thy
authors.initials: TT
authors.lastname: Do
authors.forename: Semyon
authors.initials: S
authors.lastname: Zarkhin
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Orringer
authors.forename: Shari
authors.initials: S
authors.lastname: Nemeth
authors.forename: Ted
authors.initials: T
authors.lastname: Hamilton
authors.forename: Dana
authors.initials: D
authors.lastname: Sachs
authors.forename: John J
authors.initials: JJ
authors.lastname: Voorhees
authors.forename: Sewon
authors.initials: S
authors.lastname: Kang
mesh_terms: D000152:Acne Vulgaris / Q000209:etiology / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005145:Face; D005148:Facial Dermatoses / Q000209:etiology / Q000473:pathology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology; D008297:Male; D010781:Photography / Q000379:methods*