Objective assessment of involved surface area in patients with psoriasis.
OBJECTIVE
Although difficult, it is essential to assess the disease severity of psoriasis objectively. The visual grading method currently used for assessing the involved surface area in patients with psoriasis, which is included on the Psoriasis Area and Severity Index (PASI) scoring system, is a subjective method. The aim of this study was to establish the reliable objective method, in estimating the involved surface area in patients with psoriasis.


METHODS
Thirty patients with psoriasis participated in this study. The skin lesions of each patient were estimated using the visual grading method and an image analysis system.


RESULTS
The differences between five dermatologists' estimates of the involved surface area obtained from the visual grading method were highly significant (P<0.05, Kruskal-Wallis test). The comparison between the visual grading method and the image analysis system showed that the involved areas measured by the visual grading method were significantly higher than those from the image analysis (P<0.05, Wilcoxon signed rank test).


CONCLUSIONS
The visual grading method was neither objective nor reproducible. On the other hand, the image analysis system can be used as an objective method of measuring the involved surface area of patients with psoriasis. Therefore, the image analysis system can be used as a standard for the assessment of the involved area of patients with psoriasis.
Yune
Young-Min
YM
Department of Dermatology, College of Medicine, Korea University, Seoul, Korea.
Park
Sang Yong
SY
Oh
Hyun Sook
HS
Kim
Dong-Jun
DJ
Yoo
Dong-Su
DS
Kim
Il-Hwan
IH
Moon
Jong-Sub
JS
Kim
Min-Ki
MK
Oh
Chil-Hwan
CH
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010147:Pain Measurement / Q000592:standards*; D011565:Psoriasis / Q000473:pathology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index