title: A pilot study on the Psoriasis Area and Severity Index (PASI) for small areas: Presentation and implications of the Low PASI score.
abstract: BACKGROUND
  The Psoriasis Area and Severity Index (PASI) is not able to measure small affected areas in a body region which is important for assessing the performance of high-effective treatment.
  
  
  OBJECTIVE
  To present the Low PASI score, show the difference between the classic PASI and the Low PASI, evaluate the inter-observer agreement of both scores, and compare the two scores within investigators.
  
  
  METHODS
  Cross-sectional study. Two investigators independently assessed the classic PASI and the Low PASI in 10 patients with mild-to-moderate plaque psoriasis. Differences in outcome between the two scores were calculated. Intra-class correlation coefficients (ICC) were used to determine the inter-observer agreement and to compare measurements of the two scores within both investigators. Prediction limits of 95% for the errors in measurements were provided.
  
  
  RESULTS
  In both investigators, Low PASI was mean 1.71 and 1.76, whereas the classic PASI was mean 4.14 and 4.33. The inter-observer agreement (ICC) was excellent for both investigators in both scores (ICC classic PASI = 0.95 and Low PASI = 0.87).
  
  
  CONCLUSIONS
  The Low PASI score allows more possible scores at lower levels of psoriasis extent (affected areas lower than 10% in a body region) compared to the classic PASI. This new score may lead to a more precise analysis of treatment responses and may have important clinical implications.
authors.affiliation: Department of Dermatology and.
authors.forename: M E
authors.initials: ME
authors.lastname: Otero
authors.forename: M J
authors.initials: MJ
authors.lastname: van Geel
authors.forename: J C M
authors.initials: JC
authors.lastname: Hendriks
authors.forename: P C M
authors.initials: PC
authors.lastname: van de Kerkhof
authors.forename: M M B
authors.initials: MM
authors.lastname: Seyger
authors.forename: E M G J
authors.initials: EM
authors.lastname: de Jong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011565:Psoriasis / Q000473:pathology* / Q000628:therapy; D012720:Severity of Illness Index; D055815:Young Adult
keywords: Body surface area; PASI; Psoriasis Area and Severity Index; psoriasis