Lichenoid dermatitis preceding Stevens-Johnson syndrome in a patient treated with nivolumab.

Nivolumab is an immune checkpoint inhibitor acting on programmed cell death protein 1 (PD-1) that has been used to treat a growing number of malignancies. Cutaneous side effects are common with nivolumab treatment, though they are typically self-limited. Here we present a case of persistent lichenoid dermatitis in a patient treated with nivolumab for renal cell cancer. The patient then developed Stevens-Johnson syndrome 9 months after initiation of nivolumab, with no other identifiable offending medication in the interim. Although an unusual presentation, a growing number of cases have reported delayed Stevens-Johnson syndrome/toxic epidermolytic necrosis-like reactions to immune checkpoint inhibitors. Awareness of this phenomenon is imperative for prompt recognition and treatment of potentially life-threatening cutaneous side effects.