Intermittent Purpura Development Associated with Leukocytoclastic Vasculitis Induced by Infliximab for Crohn's Disease.

Anti-tumor necrosis factor (TNF) α agents, widely used for the treatment of Crohn's disease (CD), can sometimes induce skin-associated adverse events, which mainly include psoriasis-like eruptions, eczema, and cutaneous infections. In contrast, purpura caused by vasculitis is rarely seen. We herein report a unique case of leukocytoclastic vasculitis induced by infliximab administered for CD in which intermittent purpura development was noted. Fluorescent immunostaining showed no immunoglobulin A deposition on the vessel walls. No purpura was initially seen after starting infliximab, but it appeared approximately 10 months later; however, administration did not have to be discontinued, and the condition was later resolved. The present findings provide important details regarding vasculitis induced by anti-tumor necrosis factor-α agent administration.