Abstract: Immune checkpoint inhibitors are a new type of anti-tumor immunodrugs, but due to the activation of the immune system, it can cause immune-related adverse events (irAEs). The incidence of irAEs in dermatology is about 40%, including psoriasis, eczema, vitiligo, bullous diseases, severe drug eruptions and alopecia. This patient had a 22-year history of psoriasis and recurred after 6 weeks of treatment with tislelizumab for ureteral cancer. Tislelizumab was discontinued, and the patient was treated with oral methotrexate, topical corticosteroid cream, and UVB phototherapy. Most of the lesions subsided after treatment for 1 month. During 1 year follow-up, psoriasis lesions were well controlled with topical medication, and no tumor progression was observed.

Key words: PD-1 inhibitor, tislelizumab, plaque psoriasis, immune-related adverse