Polyarteritis nodosa diagnosed by surgically resected jejunal necrosis following acute abdomen

The differential diagnosis of acute abdomen is typically extremely broad in range, with vasculitis posing a rare but potentially life-threatening cause of acute abdomen. Here, we report a case of acute abdomen with bowel wall thickening limited to jejunum, accompanied by unexplained renal dysfunction. Later, the patient was diagnosed as having polyarteritis nodosa based on surgically resected jejunal necrosis. Despite aggressive treatment, including the use of steroid pulse therapy and continuous hemodiafiltration, the patient died. Although polyarteritis nodosa is extremely rare in patients with acute abdomen, acute abdomen is relatively common manifestation of that. And it is reported that involvement of small intestine suggests poorer prognosis. Our case highlights the importance of vasculitis as a differential diagnosis of patients with atypical acute abdomen. In this report, we not only review possible clues that might have led to an earlier diagnosis in this case, but also attempt to draw some lessons for treating similar cases in the future.