Immune checkpoint inhibitor-induced bullous pemphigoid: A clinical review

Immune checkpoint inhibitor-induced bullous pemphigoid (ICI-BP) is a rare yet debilitating cutaneous immune-related adverse event characterized by auto-antibody attachment to subepidermal anchoring proteins causing tense bullae and pruritus. Clinical presentation of ICI-BP is variable and may be characterized by extended latent periods or prolonged periods of rash-free pruritus, often hindering prompt diagnosis. Accurate diagnosis of ICI-BP may warrant both tissue and serum analysis with direct immunofluorescence, enzyme-linked immunosorbent assay and/or indirect immunofluorescence. Currently, a standardized treatment approach is lacking; however, the advent of biologics, including dupilumab, omalizumab, and rituximab, and Janus kinase inhibitors targeting the underlying immunopathogenesis of ICI-BP may provide more targeted therapeutic options and reduce the need for suppressive therapies and/or cessation of immunotherapy. In this article, we provide a comprehensive review of the existing literature detailing the clinical presentation, diagnosis, management, and prognosis of ICI-BP, highlighting our own clinical experience and recommendations.