A Case Report: Severe Bullous Skin Reaction Induced by Anti-PD-1 Antibody (Toripalimab) Therapy in a Patient with Thymic Carcinoma

The development of immune checkpoint inhibitors, such as those targeting programmed cell death protein 1 (PD-1), represents a major breakthrough in cancer therapy. Although immune checkpoint blockade therapy has a favorable risk/benefit ratio, it causes significant immune-related adverse events (irAEs), such as cutaneous reactions, in particular, severe bullous skin reactions and toxic epidermal necrolysis. Here, we report a case of a 51-year-old woman with malignant thymoma who developed a severe bullous skin reaction (characterized by a systemic rash, bullae, epidermal desquamation, and Stevens-Johnson syndrome) as a result of treatment with the PD-1 inhibitor toripalimab. The patient was treated with high doses of glucocorticoid, intravenous immunoglobulin, and intensive care, and eventually recovered from the severe irAEs. The intravenous injection of anti-PD-1 antibodies induces cutaneous reactions, which are associated with higher mortality rates. High doses of glucocorticoid combined with intravenous immunoglobulin are effective in alleviating such irAEs. Thus, improving the level of care and preventing skin infections can effectively reduce the risk of death.