title: Inter- and intra-variability of pigmented skin lesions: could the ABCD rule be influenced by host characteristics?
abstract: OBJECTIVE
  Many differences in color, shape and dimension exist between different moles even in the same individual. Major differences might be accounted for anatomical location, genetic factors and by environmental factors, mainly sunlight exposure. Therefore, it would be of great value, when evaluating skin lesions, to take into account the degree of intra- and inter-variability of several diagnostic parameters. In order to assess the morphologic and chromatic differences between lesions belonging to different patients and between lesions belonging to the same individual, we examined objective digital parameters obtained with dermatoscopic analysis, using the DBDermo MIPS system (BIO MIPS Engineering, S.R.L, siena, Italy).
  
  
  METHODS
  The automatic classifier inside the software is based on a 'match by similarity' algorithm, based on the measurement of the Euclidean distances of all variables considered from the reference image. Two-hundred and four clinically benign pigmented lesion, belonging to 18 patients were examined, stored and automatically processed. For each lesion objective parameters related to geometry, color and texture were automatically evaluated.
  
  
  RESULTS
  We found skin color (healthy skin) is objectively different from subject to subject and the lesion color is more similar among different lesions of the same patient than among lesions belonging to different individuals both in their darkest and slightly dark component. We also observed that lesion dimensions are individual correlates, i.e. the probability for a lesion to be large is higher when the other, in the same patient, is large.
  
  
  CONCLUSIONS
  Many parameters of pigmented skin lesions evaluated by digital dermoscopy analysis are similar in the same patient and different from those belonging to different individuals. This indicates that, when considering a lesion, we should take into account the peculiar patient's characteristics.
authors.affiliation: Department of Clinical Medicine and Immunological Sciences--Section of Dermatology, University of Siena, Siena, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Burroni
authors.forename: Giordana
authors.initials: G
authors.lastname: Dell'Eva
authors.forename: Rosamaria
authors.initials: R
authors.lastname: Corona
authors.forename: Francesco
authors.initials: F
authors.lastname: Sera
authors.forename: Riccardo
authors.initials: R
authors.lastname: Bono
authors.forename: Paolo
authors.initials: P
authors.lastname: Sbano
authors.forename: Lucio
authors.initials: L
authors.lastname: Andreassi
authors.forename: Pietro
authors.initials: P
authors.lastname: Rubegni
mesh_terms: D003936:Diagnosis, Computer-Assisted; D006801:Humans; D009508:Nevus, Pigmented / Q000473:pathology* / Q000503:physiopathology*; D012867:Skin / Q000473:pathology*; D012880:Skin Pigmentation