A Unique Infusion Reaction to Vedolizumab: A Case of Henoch-Schonlein Purpura: 2017 ACG Case Reports Journal Award; 2017 Presidential Poster Award

Abstract

Vedolizumab is a novel monoclonal antibody against integrin α4β7 that was recently approved to treat moderate to severe inflammatory bowel disease (IBD). Side effects are thought to be similar to other biologics used to treat IBD and include infections and acute infusion reactions. However, given its relatively recent approval, few case reports on unique side effects have been published. We present the case of a 53 year old man with a history of Crohn's disease (CD) diagnosed 16 years prior and on vedolizumab as well as oral steroids with good control of his symptoms. The patient underwent his 14th vedolizumab infusion without incident. However, he noted an itchy rash on the dorsum of his feet and ankles roughly 5 hours after the infusion was completed. The rash spread cranially up to his buttocks and he concurrently developed bilateral ankle and knee pain. In addition, he noted significant fatigue. Given this, he presented to the emergency room and was found to have a purpuric rash on his lower extremities. Labs revealed an erythrocyte sedimentation rate of 67 mm/hr and a creatinine of 1.34mg/dL (baseline creatinine of 1.1). A skin biopsy was done, showing moderately severe IgA associated leukocytoclastic vasculitis without neutrophilia, consistent with a diagnosis of Henoch-Schonlein Purpura (HSP). Vedolizumab is a relatively novel agent being used to treat moderate to severe IBD and few side effects have been reported in the literature. HSP is an acute IgA mediated vasculitis of the small vessels that commonly causes symptoms in the skin, kidneys, lungs and central nervous system. Hallmark symptoms of HSP include a purpuric rash on the lower extremities with abdominal pain, bloody diarrhea, joint pain (often in the ankles and knees), and renal failure. While HSP often starts after an upper respiratory infection in young children, it can also be triggered by drugs such as Vancomycin, ACE inhibitors and ranitidine, likely through a type-three hypersensitivity reaction. However, this is the first case in the literature of a case of HSP secondary to a vedolizumab infusion. Clinicians who prescribe vedolizumab should be aware of this as a possible reaction, especially if patients develop a lower extremity rash in the immediate post infusion period.