Lichen planus pemphigoides after pembrolizumab immunotherapy in an older man

An 84-year-old Chinese man with stage IV non-small cell lung cancer was initiated on pembrolizumab, an anti-programmed cell death (PD)-1 monoclonal antibody, 4 times per week. Seven weeks later, on the day of his third cycle, he developed a rash on his chest and right axilla, which subsequently resolved with 1% hydrocortisone cream, and there