A153 Recurrent Henoch-Schonlein Purpura Following Treatment With Adalimumab

Abstract

Background Anti Tumour Necrosis Factor-α agents have revolutionised the management of inflammatory bowel disease. Cutaneous adverse events complicate therapy in up to 20% of cases. Most reactions are mild and do not warrant a change of therapy. Henoch–Schönlein purpura (HSP) has rarely been associated with anti-TNFα therapy. It is an acute vasculitis of small vessels that presents with cutaneous purpura of the lower limb, arthritis, nephritis and gastrointestinal involvement. Aims To describe the clinical course of a 16-year-old male presenting with recurrent HSP secondary to adalimumab for treatment of inflammatory bowel disease Methods A retrospective chart review of the patient’s electronic medical record. A literature review of the relevant medical literature. Results History 16 year old boy with Crohn’s disease, initial induction with exclusive enteral nutrition and maintained on adalimumab monotherapy since May 2017. Adalimumab initially 40 mg every 2 weeks, increased to every 10 days in September 2019 due to loose stool and mild inflammation throughout the colon on reassessment colonoscopy. Four separate incidences of purpuric rashes occurring 2–3 days after receiving adalimumab between November 2019 and July 2020. Purpura and petechiae of the lower limb with associated swelling of the feet and heel pain consistent with HSP. Purpura resolved within 1 to 3 weeks, treated with oral steroids on 1 occasion. First episode occurred following increase in dose frequency to every 10 days. Adalimumab frequency was further increased to every 7 days in March 2020. Following this he had 3 further HSP episodes. There was no history of preceding illness or other clear inciting event for HSP. Physical Exam Scattered petechiae on the lower limb bilaterally with large palpable purpura to his feet. Mild swelling to the right foot with tenderness to heel on palpation. Nil other joint swelling. No petechiae elsewhere. Investigations Urinalysis showed trace blood, no proteinuria. Mildly elevated CRP and ESR. Fecal calprotectin elevated >1800. Clinical Progress Rheumatology and Dermatology were consulted. Due to recurrent HSP and active luminal Crohn’s disease on repeat colonoscopy, adalimumab was discontinued and he started Ustekinumab September 2020. There has been no recurrence of relapsing rash and joint pains. Conclusions Four previous cases of HSP associated with Adalimumab have been described, three with Crohn’s disease and 1 with Ulcerative Colitis. Cutaneous manifestations occurred within 18 months of treatment in all previously reported cases. Our patient was treated with Adalimumab for 30 months prior to his first episode of HSP. This association with HSP is not unique to adalimumab, extending to other members of the anti TNFα class including infliximab and etanercept. Hypothesized mechanisms include antibody production, eosinophil activation, shifts in T cell responses and direct drug toxicity to vessel walls. Funding Agencies None