Emergence of Takayasu Arteritis and Chronic Recurrent Multifocal Osteomyelitis during Maintenance Therapy in Remission 13 Years after the Diagnosis of Very Early-Onset Ulcerative Colitis: A Case Report.

Introduction: Inflammatory bowel disease (IBD) is associated with Takayasu arteritis (TAK). Chronic recurrent multifocal osteomyelitis (CRMO) is a nonbacterial osteomyelitis that occurs at multiple sites, some of which are associated with IBD. We herein report a pediatric patient diagnosed with CRMO and TAK 13 years after the onset of very early-onset ulcerative colitis (VEO-UC). Concurrent presentations of UC, TAK, and CRMO are extremely rare. Case Presentation: A 15-year-old female diagnosed with VEO-UC at 22 months developed CRMO and TAK 13 years later despite maintained remission on infliximab. The patient was presented with knee pain and fever. 18-fluorodeoxyglucose positron emission tomography revealed not only multiple bone uptake but also arterial wall thickening. Contrast-enhanced magnetic resonance imaging showed circumferential wall thickening from distal aortic arch to descending aorta. Bone biopsy confirmed chronic osteomyelitis without infection. TAK (type IIb) and CRMO were diagnosed. Methylprednisolone pulse therapy was administered for induction. Treatment was switched to adalimumab (ADA), which has reported efficacies for all three conditions. However, only TAK did not achieve remission. ADA was switched to tocilizumab (TCZ) without changing other medications to treat TAK, successfully achieving remission of all three diseases and allowing steroid reduction. Conclusion: Clinicians should consider concurrent vasculitis and CRMO when IBD patients present with unexplained inflammatory responses. TCZ may effectively treat TAK developing in anti-tumor necrosis factor-treated UC patients.