Cutaneous autoimmune effects in the setting of therapeutic immune checkpoint inhibition for metastatic melanoma.

Therapeutic immune checkpoint blockade for metastatic melanoma has been associated with vitiligo, pruritus and morbilliform eruptions. Reports of other autoimmune skin disease in this setting are rare. We sought to expand the spectrum of cutaneous immune-mediated effects related to immune checkpoint inhibitor therapy. In this report, we describe two unusual cutaneous reactions related to checkpoint inhibitor therapy, namely bullous pemphigoid (BP) and dermatitis herpetiformis. The development of BP and dermatitis herpetiformis in the context of checkpoint inhibitor therapy is consistent with previous investigations supporting the importance of effector and regulatory T cells in the pathogenesis of these diseases.