title: A proposed scoring system for assessing the severity of actinic keratosis on the head: actinic keratosis area and severity index.
abstract: BACKGROUND
  Actinic keratosis (AK) severity is currently evaluated by subjective assessment of patients.
  
  
  OBJECTIVE
  To develop and perform an initial pilot validation of a new easy-to-use quantitative tool for assessing AK severity on the head.
  
  
  METHODS
  The actinic keratosis area and severity index (AKASI) for the head was developed based on a review of other severity scoring systems in dermatology, in particular the psoriasis area and severity index (PASI). Initial validation was performed by 13 physicians assessing AK severity in 18 AK patients and two controls using a physician global assessment (PGA) and AKASI. To determine an AKASI score, the head was divided into four regions (scalp, forehead, left/right cheek ear, chin and nose). In each region, the percentage of the area affected by AKs was estimated, and the severities of three clinical signs of AK were assessed: distribution, erythema and thickness.
  
  
  RESULTS
  There was a strong correlation between AKASI and PGA scores (Pearson correlation coefficient: 0.86). AKASI was able to discriminate between different PGA categories: mean (SD) AKASI increased from 2.88 (1.18) for 'light' to 5.33 (1.48) for 'moderate', 8.28 (1.89) for 'severe', and 8.73 (3.03) for 'very severe' PGA classification. The coefficient of variation for AKASI scores was low and relatively constant across all PGA categories.
  
  
  CONCLUSIONS
  Actinic keratosis area and severity index is proposed as a new quantitative tool for assessing AK severity on the head. It may be useful in the future evaluation of new AK treatments in clinical studies and the management of AK in daily practice.
authors.affiliation: Centroderm Clinic, Wuppertal, Germany.|Faculty of Health, University Witten-Herdecke, Witten, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Dirschka
authors.affiliation: Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Pellacani
authors.affiliation: Dermatology Clinic, University of Catania, Catania, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Micali
authors.affiliation: Melanoma Unit, Dermatology Department, Hospital Clínic de Barcelona, IDIBAPS, Universitat de Barcelona, Barcelona, Spain.|Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Valencia, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Malvehy
authors.affiliation: First Department of Dermatology, Andreas Sygros Hospital, University of Athens Medical School, Athens, Greece.
authors.forename: A J
authors.initials: AJ
authors.lastname: Stratigos
authors.affiliation: Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Casari
authors.affiliation: Centroderm Clinic, Wuppertal, Germany.|Department of Dermatology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Schmitz
authors.affiliation: Department of Dermatology, Monklands Hospital, Lanarkshire, UK.|University of Glasgow, Glasgow, UK.
authors.forename: G
authors.initials: G
authors.lastname: Gupta
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006257:Head; D006801:Humans; D055623:Keratosis, Actinic / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index