Two rare cases of bullous pemphigoid associated with immune checkpoint inhibitors

Bullous pemphigoid is a rare and severe adverse reaction to immune-checkpoint inhibitors that can be life-threatening. Here, we present two cases of bullous pemphigoid secondary to nivolumab and ipilimumab+nivolumab therapy, respectively. Both cases presented months after discontinuation of immunotherapy. Our first case highlights the life-threatening nature of bullous pemphigoid due to its potential to cause laryngeal oedema. Our second case illustrates that cytotoxic T-lymphocyte-associated protein-4 inhibitors can rarely lead to bullous pemphigoid, in addition to programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1) inhibitors. Both cases emphasise the importance of skin examinations and dermatological follow-up for patients during and even after discontinuation of immunotherapy.