Immune-related adverse events (irAEs) are a class-effect of checkpoint inhibitors (CIs). The development of a Bullous pemphigoid (BP)-like blistering disease, driven by autoantibodies against the hemidesmosomal protein BP180, is a potentially serious irAE whose incidence seems to be increasing. We therefore set out to characterize the clinical and (immuno)histopathological features and treatment responses of cases of BP which developed during or after CI therapy collated in six German tertiary referral centers between 2014 and 2018. We identified twelve cases of BP which emerged during and/or after CI therapy. The time interval between the initiation of CI therapy and the diagnosis of BP was 3-74 weeks (median: 23 weeks). Age at the time of diagnosis of BP varied between 62 and 80 years (median: 76 years). The clinical presentation of the patients was diverse but the severity was relatively mild when compared to that seen in most cases of spontaneous BP. Only four patients met all of the immunopathological criteria recommended in the European guidelines for the diagnosis of BP. Topical corticosteroid treatment was sufficient to achieve disease control in most patients. CI therapy could be continued in 8 out of 12 patients. In summary, our study indicates that cases of BP during or after CI therapy bear several peculiarities distinguishing them from spontaneous BP. Given the diversity of the clinical presentation of CI-induced BP the application of existing diagnostic algorithms developed for spontaneous BP can be utilized to uncover the frequency and features of CI-induced BP and to develop and optimize management algorithms., Competing Interests: DG reports personal fees and other from Pierre Fabre Pharma Gmbh, personal fees and other from Roche Pharma AG, personal fees and other from Bristol-Myers Squibb GmbH & Co. KGaA, personal fees and other from Novartis Pharma GmbH, personal fees and other from Sanofi-Aventis GmbH, during the conduct of the study; other from Amgen GmbH, other from Janssen-Cilag GmbH, other from Galderma Laberatorium GmbH, outside the submitted work. RG reports personal fees and non-financial support from BristolMyersSquibb, personal fees and non-financial support from Roche Pharma, grants, personal fees and non-financial support from Merck Serono, grants, personal fees and non-financial support from Amgen, personal fees and non-financial support from Pierre Fabre, grants, personal fees and non-financial support from Sanofi Regeneron, personal fees from MerckSharpDohme, grants, personal fees and non-financial support from Novartis, personal fees from Almirall Hermal, grants and personal fees from Pfizer, personal fees from SUN Pharma, personal fees from 4SC, grants from Johnson&Johnson outside the submitted work. RH reports personal fees from ROCHE, personal fees from BMS, personal fees from MSD, personal fees from Novartis, personal fees from Pierre-Fabre, outside the submitted work. EL reports personal fees and non-financial support from BristolMyersSquibb, personal fees and non-financial support from Novartis, Meeting and travel support from Curevac and advisory board fees from Sun Pharma. CL reports personal fees from BMS, personal fees from MSD, personal fees from Sanofi, personal fees from Novartis, personal fees from Roche, personal fees from Pierre Fabre, personal fees from Amgen, personal fees from Kyowa Kirin, personal fees from Biontech, personal fees from Almiral Hermal, personal fees from Sun Pharma, personal fees from Merck, outside the submitted work. PT: speaker´s honoraria from BMS, Novartis, MSD, Pierre-Fabre, CureVac and Roche, consultant´s honoraria from BMS, Novartis, Pierre-Fabre, Merck Serono, Sanofi und Roche and travel support fom BMS, Pierre-Fabre and Roche. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Sadik, Langan, Gutzmer, Fleischer, Loquai, Reinhardt, Meier, Göppner, Herbst, Zillikens and Terheyden.)