The cutaneous lupus erythematosus disease area and severity index: a responsive instrument to measure activity and damage in patients with cutaneous lupus erythematosus.

OBJECTIVE To assess the clinical responsiveness of the CLASI (Cutaneous Lupus Erythematosus [CLE] Disease Area and Severity Index). DESIGN Validation cohort. SETTING Tertiary referral center. Patients Eight patients with CLE. Intervention Assessment of patients with CLE from baseline until day 56 after starting a new standard of care therapy. MAIN OUTCOME MEASURES Correlation of the baseline to day-56 change in 2 CLASI scales (disease activity and damage), with baseline to day-56 change in the physicians' and patients' assessments of patient's global skin health scores, and the patients' assessments of pain and itch. RESULTS The change in CLASI activity score highly correlated with the changes in 3 clinical validation measures: physicians' assessment of skin health (r = 0.97; P = .003; n = 7), patients' global skin health score (r = 0.85; P = .007; n = 8), and pain (r = 0.98; P = .004; n = 5). Using the Wilcoxon signed-rank test, paired baseline to day-56 changes in CLASI activity and damage scores were analyzed for the 2 subgroups (meaningful change vs nonmeaningful change) composing each validation variable. Change in CLASI activity was significantly different for patients who had a meaningful change in their global skin self-ratings (Z = 1.07; P = .03) and approached statistical significance for patients who had a meaningful change in their level of itching (Z = 1.83; P = .06) and their physicians' global skin rating (Z = 1.84; P = .06). The CLASI activity score decreases after successful therapeutic intervention, whereas the damage score may increase in scarring forms of CLE. Conclusion The activity score of the CLASI correlates with the improvement of global skin health, pain, and itch and is thus a useful tool to measure clinical response.