Diagnosis of Adult IgA Vasculitis With Gastrointestinal Involvement

Immunoglobulin A vasculitis (IgAV) is challenging to diagnose in patients with isolated gastrointestinal (GI) manifestations, as clinical symptoms and endoscopic findings are variable, in addition to mimickers of the disease. Delayed diagnosis can lead to inadequate treatment and complications such as GI bleeding or bowel perforation. We present a case of IgAV in an older man with immunosuppression who presented with abdominal pain, vomiting, and hematochezia. Through serologic testing, radiographic imaging, and repeat endoscopies, the underlying diagnosis evolved from infectious enteritis to mesenteric ischemia, to inflammatory bowel disease, and colchicine toxicity before arriving at the final diagnosis of IgAV.