Remote presentation of nivolumab-induced bullous pemphigoid in hepatocellular carcinoma

A man in his 70s with a history of unresectable hepatocellular carcinoma (HCC) treated with nivolumab presented with a blistering rash 14 months after nivolumab initiation. Biopsies and direct immunofluorescence confirmed the diagnosis of bullous pemphigoid (BP). BP is an autoimmune skin disorder in which autoantibodies bind to the dermal-epidermal junction. It is a rare sequela of programmed cell death protein-1 (PD-1) inhibitors that can develop after treatment initiation and typically resolve soon after discontinuation. Most cases are reported in melanoma and non-small cell lung cancers, and rarely in HCC irrespective of the timing of onset. We describe a rare presentation of remote BP with PD-1 inhibitor use in HCC. PD-1 inhibitor-induced BP is a rare cutaneous immune-related adverse event, and this case highlights the variability in onset and chronicity.