P027 Vedolizumab induced extensive purpuric dermatitis in patient with severe Crohn's disease: A case report
Authors: Glenn Harvin , Maliha Naseer 
Published: July 2019

INTRODUCTION:
Crohn's disease is an idiopathic and inflammatory disease of the intestinal tract associated with significant morbidity and mortality. Currently available treatment options for Crohn's disease includes anti-inflammatory drugs, immunosuppressant, biologic agents, antibiotics, and drugs for symptomatic relief. However, variety of dermatological side effects has been reported in literature associated with these modalities. Vedolizumab is approved to induce and maintain remission in moderate to severe Crohn's disease with relatively low side effect profile. Here we present the first reported case of extensive purpuric dermatitis associated with Vedolizumab.

CASE:
A 56-year-old African American male with history of severe Crohn's disease presented with the complains of extensive bilateral lower extremity rash. Crohn's disease was diagnosed in 2012 involving duodenum and terminal ileum. He was previously treated but failed to respond to 6 mercaptopurine (6-MP), mesalamine, steroids and infliximab infusions. Vedolizumab was started after he failed infliximab. According to patient he noticed rash first time 5 days after first dose of Vedolizumab. He received total of 4 biweekly doses of Vedolizumab before presentation to clinic with rash. Rash was pruritic in nature and started on ankle and progressively got worsened involving legs and thighs. Patient denied history of fever and chills. Review of system was negative. On physical examination well-demarcated, brownish pigmentation over the lower extremities were noticed. He denied use of any other newly prescribed or over the counter medications. Patient underwent a formal dermatologic evaluation. Shave biopsy was done that showed irritated hyper and parakeratotic skin with spongiosis, extravasated red blood cells and inflammatory infiltrate comprising of lymphocytes, histiocytes, neutrophils and eosinophils findings consistent with drug induced purpuric dermatitis. Patient was started on topical triamcinolone. He reported slight improvement in his rash one month after Vedolizumab infusion was discontinue.

DISCUSSION:
Vedolizumab is a humanized monoclonal antibody that selectively inhibits the binding of α4β7 integrin to intestinal mucosal cell adhesion molecule (MAdCAM-1) and has no effect on α4β1 integrin adhesion on the vascular cell adhesion molecule 1 (VCAM-1). As a result, cutaneous migration of lymphocytes including by VCAM-1 is unaffected. Cutaneous complications of Vedolizumab including rash and hypersensitivity reaction are reported in <1% of patient. Till date only one report of Vedolizumab associated paradoxical psoriasis has been reported. This is the first reported case of extensive purpuric dermatitis (PD) associated with Vedolizumab. Exact etiology of PD is unknown but cell-mediated immunity might play a role. This inflammatory infiltrate leads to vascular fragility and subsequent leakage of erythrocytes. Management of drug induced PD involves discontinuation of offending medication. Topical corticosteroid therapy may be of some help, especially for pruritus, but prolonged use should be avoided.

CONCLUSION:
Though dermatological complications associated with Vedolizumab are rare but can be potentially debilitating for our patients. Prompt identification and discontinuation of Vedolizumab is critical in preventing morbidity associated with these side effects.