title: Measurement of color parameters of psoriatic plaques by narrow-band reflectance spectrophotometry and tristimulus colorimetry.
abstract: Color parameters were measured on 50 psoriatic plaques in 10 patients, after scoring the amount of scales on them by inspection, with a narrow-band reflectance spectrophotometer (erythema/melanin index expression) and tristimulus colorimeter (CIE L*a*b* expression). Both erythema index a* (redness) were highest in the group of erythematous plaque with little scale (twice as high as in controls) and decreased significantly as the plaques were covered with thicker scale, while L* (brightness) changed in just the opposite fashion of a*. These portable 'color indicators' can be utilized to express the appearance of psoriatic plaques quantitatively, especially the extent of erythema and the amount of the scale on it.
authors.affiliation: Department of Dermatology, School of Medicine, University of Tokushima, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Takiwaki
authors.forename: J
authors.initials: J
authors.lastname: Serup
mesh_terms: D000328:Adult; D000368:Aged; D003116:Color; D003124:Colorimetry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000473:pathology*; D012867:Skin / Q000473:pathology*; D013053:Spectrophotometry