Refractory urticarial vasculitis as a complication of ulcerative colitis successfully treated with rituximab.

Ulcerative colitis can be complicated by the development of leukocytoclastic vasculitis, a cutaneous vasculitis with the potential for systemic involvement. We present a man with a history of ulcerative colitis complicated by end-stage liver disease secondary to sclerosing cholangitis requiring a liver transplant. The patient developed new-onset vasculitis and diarrhea refractory to therapy with standard immunosuppression. He was treated with anti-CD20 therapy with a positive response. The basis of the vasculitis was likely one related to an underlying monoclonal paraprotein with cryoprecitable properties. Treatment with anti-B-cell therapy may be a new treatment option for patients with gammopathy-associated leukocytoclastic vasculitis.