Development of the CLASI as a Tool to Measure Disease Severity and Responsiveness to Therapy in Cutaneous Lupus Erythematosus

Abstract

The Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) is a clinical tool that quantifies disease activity and damage in cutaneous lupus erythematosus (CLE). The activity score is based on the degree of erythema, scale, mucous membrane lesions, and nonscarring alopecia.¹ Unlike other outcome measures in dermatology, CLASI scores are not based solely on the area of involved skin; rather, parts of the body that are most visible are weighted more heavily than those that are usually covered.¹ The CLASI has already been shown to have good content validity, addressing the most relevant aspects of CLE as determined by an expert panel of dermatorheumatologists.¹ It also has good interrater and intrarater reliability when used by either dermatologists or rheumatologists.^1,2 Early small clinical studies have demonstrated responsiveness in all subsets of CLE, including individual lesions, localized and generalized discoid lupus erythematosus (DLE), as well as subacute cutaneous lupus erythematosus (SCLE) and tumid lupus erythematosus.^3-7