Severe Type of Erythema Multiforme (EM major) due to Administration of Anti-PD-1 Antibody Drug

Immune checkpoint inhibitors can sometimes cause unexpected skin side effects. Special attention should be paid to a severe form of erythema multiforme (EM), toxic epidermal necrolysis and Stevens-Johnson syndrome. We experienced a patient who took 10 weeks from drug discontinuation to the onset of EM major.