Open AccessObjective measurement of erythema in psoriasis using digital color photography with color calibration
Author(s) -
Raina A.,
Hennessy R.,
Rains M.,
Allred J.,
Hirshburg J. M.,
Diven D. G.,
Markey M. K.
Publication year - 2016
Publication title -
skin research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.521
H-Index - 69
eISSN - 1600-0846
pISSN - 0909-752X
DOI - 10.1111/srt.12276
Subject(s) - erythema , psoriasis , medicine , dermatology , artificial intelligence , linear discriminant analysis , calibration , photography , computer science , mathematics , statistics , art , visual arts
Background Traditional metrics for evaluating the severity of psoriasis are subjective, which complicates efforts to measure effective treatments in clinical trials. Methods We collected images of psoriasis plaques and calibrated the coloration of the images according to an included color card. Features were extracted from the images and used to train a linear discriminant analysis classifier with cross‐validation to automatically classify the degree of erythema. The results were tested against numerical scores obtained by a panel of dermatologists using a standard rating system. Results Quantitative measures of erythema based on the digital color images showed good agreement with subjective assessment of erythema severity (κ = 0.4203). The color calibration process improved the agreement from κ = 0.2364 to κ = 0.4203. Conclusion We propose a method for the objective measurement of the psoriasis severity parameter of erythema and show that the calibration process improved the results.