Objective: To evaluate the validity of the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) for use by rheumatologists via reliability testing, and to extend the validation for dermatologists.
Methods: Fourteen subjects with cutaneous lupus erythematosus (CLE; n = 10), a mimicker skin disease only (a cutaneous lesion that may appear clinically similar to CLE; n = 1), or both (n = 3) were rated with the CLASI by academic-based dermatologists (n = 5) and rheumatologists (n = 5).
Results: The dermatology intraclass correlation coefficient (ICC) was 0.92 for activity and 0.82 for damage; for rheumatology the ICC was 0.83 for activity and 0.86 for damage. For intrarater reliability, the dermatology Spearman's rho was 0.94 for activity and 0.97 for damage; for rheumatology the Spearman's rho was 0.91 for activity and 0.99 for damage.
Conclusion: Our data confirm the reliability of the CLASI when used by dermatologists and support the CLASI as a reliable instrument for use by rheumatologists.