Cutaneous lupus erythematosus: insights from molecular pathogenesis to targeted therapies

Cutaneous lupus erythematosus (CLE) is the most common organ manifestation in individuals diagnosed with systemic lupus erythematosus (SLE). CLE can occur either alone or in association with SLE; in the latter case, it substantially increases the occurrence of disease flares and can cause disfigurement. The clinical pathogenesis of CLE is well established, as exposure to ultraviolet (UV) light and/or other environmental triggers, such as smoking or drug use, can lead to keratinocyte death in genetically susceptible individuals. This in turn activates cytotoxic T cells, plasmacytoid dendritic cells (pDCs), and B cells, creating a continuous interaction between the innate and adaptive immune systems. This interaction plays a pivotal role in CLE development, driving the formation of skin lesions. However, the molecular mechanisms underlying these cutaneous manifestations are not yet fully understood. While significant advances have been made in SLE treatment over the past few decades, U.S. Food and Drug Administration (FDA)-approved therapies remain limited to hydroxychloroquine, glucocorticoids, belimumab, and anifrolumab. Although new therapies for CLE have emerged, given the highly heterogeneous nature of the condition, personalized medicine is essential to prevent disfigurement and systemic disease flares. Understanding the molecular pathogenesis of CLE is crucial for developing targeted therapies and improving patient outcomes. This review presents current insights into CLE pathogenesis, highlighting key mechanisms driving the disease and exploring recent advances in treatments that have shown promise in clinical practice.