Immunotherapy-Related Cutaneous Leukocytoclastic Vasculitis in a Patient With Metastatic Renal Cell Carcinoma

Leukocytoclastic vasculitis (LCV) is a small-vessel vasculitis that presents as cutaneous palpable purpura. It is typically seen as a reaction to infection or certain drugs, most commonly nonsteroidal anti-inflammatory drugs or beta-lactams. Although less common, LCV can present as an adverse reaction to checkpoint inhibitor immunotherapy. Here, we present a rare case of an immunotherapy-induced LCV in a patient with metastatic renal cell carcinoma who was treated with nivolumab. This case highlights a rare side effect of a commonly used immunotherapy and highlights how quick recognition and initiation of treatment can easily improve clinical outcomes.