Clinical characteristics, treatment and outcome of subacute cutaneous lupus erythematosus induced by PD-1/PD-L1 inhibitors.

PD-1/PD-L1 inhibitors have increasingly been associated with the occurrence of subacute cutaneous lupus erythematosus (SCLE), but the clinical characteristics and outcomes remain under-explored. Literature on PD-1/PD-L1 inhibitors induced SCLE was retrieved from Chinese and English databases until June 31, 2024, and clinical data of patients were extracted for retrospective analysis. Twenty-nine patients participated, with a median age of 63 years (range 43, 80). The most frequently reported drugs were Nivolumab (51.7%) and pembrolizumab (31.0%). The median time from treatment initiation to SCLE onset was 3 months (range 0.5, 47). Cutaneous manifestations presented primarily as papulosquamous lesions (65.5%) and erythema annulare (31.0%), predominantly occurring on the trunk (51.7%) and arms (51.7%). Serological analysis revealed positive anti-Ro antibodies in 91.7% of patients, positive antinuclear antibodies in 75.0%, and positive anti-La antibodies in 50.0%. Skin biopsies showed interface dermatitis in 65.5% of cases and lymphocyte infiltration in 82.8%. Treatment with topical corticosteroids, systemic corticosteroids, and hydroxychloroquine led to gradual improvement or resolution of the rash, with a median recovery time of 1 month (range 0.5, 11). As the use of PD-1/PD-L1 inhibitors in oncology increases, SCLE should be recognized as a rare cutaneous adverse effect. Histological and serological evaluations play a critical role in diagnosing SCLE. Typically, SCLE resolves on its own with appropriate local and systemic treatment.