Skin Reactions to Immune Checkpoint Inhibitors

Due to the novelty of immune checkpoint inhibitors, their cutaneous adverse events (AEs) have only been recently characterized. This, along with the substantial rate of cutaneous reactions, has left many clinicians without sufficient familiarity to diagnose and treat cutaneous AEs. Pruritus and rash are among the top five immune-related AEs reported in clinical trials for this class of therapy. Incidence varies between 35 and 60% for cutaneous AEs among the seven FDA-approved drugs used as monotherapy or combination therapy. Although only 2% are reported as grade 3 or 4 events with monotherapy, the incidence can be as high as 6-9% for combination therapy and the impact on quality of life can be significant for these patients. Of ipilimumab patients, 43.5% have a cutaneous AE, and, at our institution, 20% of them had a dose interruption as a result. This means potentially 9% of patients have dose interruption of ipilimumab because of their cutaneous AEs. In the following chapter, we review the categories of these drugs, common cutaneous effects, their grading, and management options.