Cytokine release syndrome complicated with severe rashes induced by nivolumab plus ipilimumab therapy in a patient with non‐small cell lung cancer: A case report

Cytokine release syndrome (CRS) is a severe and life‐threatening toxicity typically reported in chimeric antigen receptor T cell therapy and is rarely reported in immune checkpoint inhibitor (ICI) therapy. This study reports the case of a 75‐year‐old Japanese woman who received nivolumab plus ipilimumab therapy for the postoperative recurrence of non‐small cell lung cancer. She was admitted to our hospital with fever, hypotension, hepatic disorder, and thrombocytopenia. We observed slight skin rashes on her neck on admission, which spread rapidly across her body within a few days. We diagnosed CRS complicated by severe rashes. CRS symptoms were resolved with corticosteroid therapy, and did not recur thereafter. CRS is a rare, but important, immune‐related adverse event associated with ICI therapy.