Abstract: We reported a psoriasiform eruption after immunotherapy with a PD-1 inhibitor (tirelizumab) in a 75-year-old man with advanced lung cancer and reviewed the literature. The patient presented with scaly rash on the nail bed, then spread to the whole body, with itching and swelling of both legs after one week of treated with tirelizumab. Histopathology of the lesion showed no characteristic features of psoriasis. The diagnosis of psoriasiform eruption was made and, then the patient treated with glucocorticoid, the patient gradually improved.

Key words: tirelizumab, psoriasiform drug eruption