Aikaterini Tsiogka, Johann W. Bauer, Aikaterini Patsatsi
DOI: 10.2340/00015555-3740

Bullous pemphigoid constitutes a rare dermatological immune-related adverse event of programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors. Herein, we review all published cases of anti-PD-1/PD-L1 related bullous pemphigoid and discuss current knowledge on this condition. Clinical and diagnostic findings were found to resemble those of classic bullous pemphigoid. A delayed onset of bullous pemphigoid after commencement of immunotherapy as well as a frequent precendence of a refractory pruritic eruption prior to blister development was oberved, both posing diagnostic challenges. In addition to topical and systemic treatment, most patients required either discontinuation or permanent interruption of immunotherapy. Assessment of tumour outcome did not reveal improved survival in patients developing bullous pemphigoid during immunotherapy, as suggested for other types of skin toxicity, including vitiligo. Better understanding of the pathogenetic mechanism and prognostic implications of this increasingly-reported adverse event is essential in order to establish optimal diagnostic and therapeutic management of these patients.

Bullous pemphigoid has gained increasing recognition among cutaneous adverse events of programmed cell death protein 1/programmed cell death ligand 1 inhibitors. Its clinical presentation may vary. It is mainly characterized by the development of atypical pruritic eruption prior to blistering. Therapeutic management of bullous pemphigoid may pose challenges and may negatively affect ongoing oncological treatment. Dermatological referral, correct grading and establishment of an appropriate therapeutic algorithm may limit the unnecessary modifications of immunotherapy. Further studies may elucidate the underlying immunogenetic mechanisms of this condition and ascertain efficacy and safety of existing therapeutic agents in terms of their potential to control symptoms without affecting the antitumour effect of immunotherapy.

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