Toxic epidermal necrolysis‐like cutaneous toxicity following chimeric antigen receptor T‐cell therapy in recurrent large B‐cell lymphoma

Abstract Chimeric antigen receptor (CAR) T‐cell therapy has demonstrated remarkable success in treating various B‐cell malignancies, redirecting T‐cell cytotoxicity toward cancer cells. Despite its efficacy, CAR‐T therapy is associated with potential risks, including cytokine release syndrome (CRS) and cytopenia. We present a case of a 69‐year‐old man with diffuse large B‐cell lymphoma treated with axicabtagene‐ciloleucel CAR‐T therapy, who developed a rare and severe cutaneous toxicity resembling toxic epidermal necrolysis (TEN). The patient exhibited persistent fevers, CRS, and subsequent development of a widespread erythematous macular eruption, progressing to vesiculation with bullae. Notably, allopurinol‐induced TEN was considered with the patient's recent exposure to allopurinol, although the onset and minimal mucosal involvement did not align with typical presentations of allopurinol‐induced cases. The cutaneous reaction, distinct from typical SJS/TEN, showed minimal mucosal involvement and coincided with the cytokine release storm, differing from allopurinol‐induced TEN. Despite the absence of guidelines, the patient was managed with systemic steroids, achieving significant improvement. This case expands the spectrum of CAR‐T therapy‐related cutaneous toxicities, highlighting the need for early recognition of histopathology and tailored management by dermatologists. Further understanding of these reactions is crucial for optimizing the safety profile of this groundbreaking immunotherapy.