The iso?oncotopic response: immunotherapy?associated bullous pemphigoid in tumour footprints

This case report describes a unique distribution of bullous pemphigoid induced by cemiplimab therapy. The patient preferentially developed bullae in the scar “footprints” of previous non-melanoma skin cancers, yet traumatic scars were spared. We propose to describe this distribution as an ‘iso-oncotopic response’.