Case Report: Blister formation with transient drug hypersensitivity following CAR-T-cell therapy

We present a rare case of a 70-year-old male who developed multiple tense bullae with minimal inflammation after receiving CD19-directed chimeric antigen receptor (CAR)-T-cell therapy for diffuse large B-cell lymphoma. Although strong drug-induced lymphocyte stimulation test positivity was observed initially for multiple drugs, the reactions faded over time. Histopathology revealed subepidermal blistering with minimal inflammatory infiltration, including a mild perivascular infiltration of T lymphocytes, predominantly CD4 + cells rather than CD8 + cells. All of the previously-reported cases with CAR-T-related cutaneous eruptions involve marked inflammation. In contrast, this case may represent a unique blister formation with T-cell hyperreactivity associated with post-CAR-T immune reconstitution. A comparative analysis of previously published cases is provided.