The comparison of Nail Psoriasis Severity Index with a less time-consuming qualitative system

Objective Reliable assessment of severity in nail psoriasis is essential to document treatment responses in clinical trials and routine clinical usage. In this study the correlation between Nail Psoriasis Severity Index (NAPSI) and Cannavo's scoring system was assessed, and inter‐rater correlation of NAPSI scores were evaluated. Materials and Methods Forty‐five patients with nail psoriasis were included. Target nails were selected and graded by the first dermatologist with both scoring systems. The nails were reevaluated by the second dermatologist with NAPSI. Results The two systems were highly correlated (P < 0.001). For NAPSI inter‐rater correlation was also significant (P < 0.001). Conclusion Our results showed that the qualitative and quantitative evaluations of the same rater were similar. Although the qualitative scoring system of Cannavo's is less time consuming than NAPSI, to suggest this system inter‐rater correlations should be evaluated.