Abdominal involvement as a primary manifestation of systemic or isolated gastrointestinal vasculitis

Systemic vasculitides can cause a wide variety of gastrointestinal manifestations (GI) ranging from mild and frequently nonspecific abdominal pains to potentially life-threatening bowel perforations. Vascular involvement in systemic vasculitides can affect any GI blood vessel, most commonly mesenteric, hepatic, or splenic arteries. Inflammatory changes affecting different layers of arterial vessel walls can lead to aneurysmatic dilatation or blood vessel occlusion with subsequent organ ischemia leading to mucosal ulcerations, GI bleeding, perforations, or bowel obstruction. While the presence of extraintestinal manifestations may aid in diagnosis, delays in making appropriate diagnoses and rapid initiation of glucocorticoid and immunosuppressive treatment can have detrimental consequences. Awareness of isolated gastrointestinal vasculitis is of particular importance as it frequently remains undiagnosed until end-stage organ damage becomes apparent. Vasculitis mimics such as vascular Ehlers-Danlos syndrome or fibromuscular dysplasia add another lay of complexity in approaching patients with suspected GI vasculitis and should always be carefully considered.