The CLASI, a validated tool for the evaluation of skin disease in lupus erythematosus: a narrative review.

Cutaneous lupus erythematosus (CLE) can present with or without features of systemic lupus erythematosus (SLE), with estimates of the incidence of isolated skin disease almost equaling the incidence of those with systemic disease. However, despite the impact CLE has on a patient's quality of life (QoL), there has been no US Food and Drug Administration (FDA) approved treatment for the disease in the past 50 years. In addition, patients with skin predominant LE are often excluded from clinical SLE trials. In the rare trials that include patients with skin predominant LE, disease activity and progression in the skin are often difficult to evaluate using multi-organ outcome measures. The need for new therapies for CLE and the lack of focus on skin outcomes has led to the development of the Cutaneous Lupus Disease Area and Severity Index (CLASI), a validated organ-specific outcome measure that is not only responsive to change in disease activity and damage but also correlated to changes in a patient's QoL. This paper will emphasize the extensive validation studies performed in developing the CLASI, as well as the importance of clinical trials using the CLASI to address the need for improved therapies for patients with lupus skin manifestations.