Nivolumab Bullous Pemphigoid: Case Description and Literature Review

Nivolumab is a monoclonal antibody, belonging to the checkpoint inhibitors, recently approved for treatment of recurrent or metastatic non-small cell lung cancer, melanoma, and renal cell carcinoma. Although very efficacious, oncologic immunotherapy is associated with a new spectrum of dermatological adverse events, and spontaneous reporting is advisable to define presentation, prognosis and real-life management. In particular, development of bullous pemphigoid (BP), characterized by pathologic autoantibody formation and complement deposition in the skin. is a rare, but severe event, potentially life-threatening, which requires high doses corticosteroids, or even more aggressive immunosuppression. We describe a 73-year-old Caucasian man, under nivolumab therapy for metastatic renal carcinoma, with 2-month-history of a bullous itching eruption on the trunk and arms, rapidly responding to standard corticosteroids treatment and nivolumab dismission, supporting the decision to taper and completely interrupt steroids. Unfortunately, 3 weeks after complete steroidal washout, the itching bullous eruption relapsed, confirming that the autoimmune disease, once aroused by the drug-induced immune unbalance, has a clinical course superimposable to the idiopathic disease. Prompt referral to the dermatologist is advisable in patients under oncologic immunotherapy, developing pruritus and skin eruptions to address the correct diagnostic workup and management.