title: Comparison of actual psoriasis surface area and the psoriasis area and severity index by the human eye and machine vision methods in following the treatment of psoriasis.
abstract: The lack of a quantitative method for assessing psoriasis severity poses a problem for quality control in dermatology. Quantitative estimation of involved surface area is important, as in the psoriasis area and severity index (PASI), but the reliability of many methods is poor. The purpose of this study was to assess the involved surface area of 15 psoriasis patients before and after different anti-psoriasis treatments using the human eye method and a computer image analysis (CIA) system based on colour segmentation. The human eye assessments were compared with the results of the CIA system and the resulting effects on the PASI score were also compared. The human eye estimates were higher than those obtained by the CIA method and, as a consequence, the values of the PASI by the human eye method were also higher than those by CIA. The human eye estimates differed most in cases where the PASI was under 15. The changes in the PASI by the human eye method before and after treatments differed significantly from those by CIA. The CIA system offers a possibility to quantify actual surface in patients with psoriasis, and will be an alternative for developing quality control when evaluating different treatment efficacies.
authors.affiliation: Department of Dermatology, University of Oulu, Finland.
authors.forename: L
authors.initials: L
authors.lastname: Savolainen
authors.forename: J
authors.initials: J
authors.lastname: Kontinen
authors.forename: E
authors.initials: E
authors.lastname: Alatalo
authors.forename: J
authors.initials: J
authors.lastname: Röning
authors.forename: A
authors.initials: A
authors.lastname: Oikarinen
mesh_terms: D017255:Acitretin / Q000627:therapeutic use; D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000875:Anthralin / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D002117:Calcitriol / Q000031:analogs & derivatives / Q000627:therapeutic use; D003116:Color; D003879:Dermatologic Agents / Q000627:therapeutic use; D005123:Eye; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007641:Keratolytic Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011701:PUVA Therapy; D010781:Photography; D011565:Psoriasis / Q000188:drug therapy / Q000473:pathology*; D011786:Quality Control; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D012867:Skin / Q000187:drug effects / Q000473:pathology*; D013638:Tars / Q000627:therapeutic use
chemical_list: D000893:Anti-Inflammatory Agents; D003879:Dermatologic Agents; D007641:Keratolytic Agents; D013638:Tars; C055085:calcipotriene; D002117:Calcitriol; D017255:Acitretin; D000875:Anthralin