Polyarthritis and Psoriasiform Skin Lesions following Pembrolizumab Therapy

A notable feature of immune checkpoint inhibitor (ICI) therapy in oncology patients is its association with increased frequency of immune related adverse reactions, directly associated with their unique mechanism of action. These adverse events are of great interest to rheumatologists, as not only do they commonly require immunosuppressive therapeutic intervention, but can also aid in unveiling important immunopathogenetic pathways that underlie autoimmune phenomena. Herein we describe a case of psoriasiform skin lesions and polyarthritis in a patient receiving ICI for lung cancer.