Purpose: A 28-year-old male with a past medical history of Crohn's colitis presents with worsening abdominal pain and diarrhea. His index colonoscopy revealed pancolitis but later showed patchy colitis with sparing of the rectum and ileum. His symptoms were refractory to adalimumab and infliximab with low-dose 6-MP. The patient was positive for JC virus antibody, so natalizumab was deferred. He was started on ustekinumab and low-dose methotrexate with minimal response and developed weekly muscle swelling with associated pain and redness. Symptoms did not improve with prednisone taper. The patient was admitted for expedited management. Exam revealed abdominal tenderness without rebound as well as painful left forearm and right leg swelling. Initial labs yielded a normal WBC, mild microcytic anemia, and elevated inflammatory markers (CRP 72.5, ESR 40). Metabolic and liver panels and albumin were normal. Infectious stool studies were negative. Flexible sigmoidoscopy biopsies showed inflammation but no CMV infection. The patient was started on methylprednisolone 40mg IV daily and natalizumab 300 mg IV q4 weeks and placed on parenteral nutrition. Dermatology performed punch biopsy of a cellulitic plaque on the left forearm which revealed subcutaneous septal leukocytoclastic vasculitis (LCV). A subsequent painless rash developed, which demonstrated LCV on biopsy. Lyme, parvovirus, and hepatitis serologies; anti-Streptolysin O titers; ANCA and complements C3 and C4 were all unremarkable. Urine protein-to-creatinine ratio was normal. The patient was referred for subtotal colectomy with end ileostomy, but he wished to defer surgery. His symptoms gradually improved, and he was transitioned to an oral diet and prednisone and discharged home on natalizumab. Conclusion: LCV is believed to be an immune complex disorder that can be triggered by various drugs, infections, malignancies, and systemic and autoimmune disorders. In this case, the patient's LCV was felt likely due to his inflammatory bowel disease or possibly medication (e.g., methotrexate). The atypical appearance of his initial rash was felt due to the subcutaneous location of his LCV. LCV is less frequently seen in IBD compared to other skin manifestations such as erythema nodosum or pyoderma gangrenosum. Skin lesions of LCV usually spontaneous self-resolve or can be treated with corticosteroids, dapsone, colchicine, or immunosuppressive agents.
Read full abstract