Background: The development of activity indices for skin lesions and damage in systemic lupus erythematosus (SLE) is essential for quantifying their changes. The Cutaneous Lupus Erythematosus Severity Index (CLASI) and its revised version (R-CLASI) are tools for the quantitative assessment of changes in the skin and mucous membranes in patients with cutaneous lupus erythematosus (CLE) and its systemic variant.

Objectives: To validate the CLASI and R-CLASI indices in a Latin American cohort of patients with systemic lupus erythematosus and compare their results with dermatological evaluations of quality of life.

Methods: The study included 100 patients diagnosed with SLE, presenting various types of skin and mucosal lesions. The mean age was 42 years, with an average disease duration of 8 years. The CLASI and R-CLASI indices were used to assess active (reversible) lesions and irreversible skin damage, respectively. Additionally, the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI) were utilized for a general evaluation of activity and damage in SLE.

Results: The most common type of skin lesion in patients with SLE was acute cutaneous lupus erythematosus (ACLE), observed in 50% of cases, along with alopecia, detected in 71% of patients. The median CLASI activity index (AI) was 6, while the median R-CLASI AI was 8 points. The median CLASI damage index (PI) was 6, and the median R-CLASI PI was 3 points. A statistically significant relationship was found between CLASI and R-CLASI scores and the degree of activity in the mucocutaneous domain according to SLEDAI-2K and PI in SLE. The ROC analysis demonstrated high sensitivity (CLASI AI - 96%, R-CLASI - 91%, CLASI and R-CLASI PI - 92%) and specificity (CLASI AI - 69%, R-CLASI - 75%, CLASI and R-CLASI PI - 90%) for both indices.

Conclusion: The CLASI and R-CLASI indices effectively reflect the level of activity and severity of skin lesions, with higher values corresponding to more severe skin damage and a significant impact on the overall well-being of patients with SLE. Patients exhibiting elevated values on these indices often experience feelings of shame, discomfort, difficulties in performing daily tasks, and restrictions in social life. The use of CLASI and R-CLASI is recommended for assessing the severity of skin and mucosal membrane lesions in patients with SLE in Latin America.

REFERENCES: [1] Jolly M, Kazmi N, Mikolaitis RA, Sequeira W, Block JA. Validation of the Cutaneous Lupus Disease Area and Severity Index (CLASI) using physician- and patient-assessed health outcome measures. J Am Acad Dermatol [Internet]. 2012;68(4):618–23. Disponible en: http://dx.doi.org/10.1016/j.jaad.2012.08.035 .

[2] Kuhn A, Meuth AM, Bein D, Amler S, Beissert S, Böhm M, et al. Revised Cutaneous Lupus Erythematosus Disease Area and Severity Index (RCLASI): a modified outcome instrument for cutaneous lupus erythematosus. Br J Dermatol [Internet]. 2010;163(1):83–92. Disponible en: http://dx.doi.org/10.1111/j.1365-2133.2010.09799.x .

Acknowledgements: NIL.

Disclosure of Interests: None declared.

© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.