Necrosis of the small intestine leading to a diagnosis of polyarteritis nodosa: a case report.

Polyarteritis nodosa is a disease that presents with necrotizing vasculitis in small and medium-sized arteries. It may occur in various organs, but approximately half of cases have gastrointestinal involvement. Prognosis is not favorable once organ dysfunction begins as evidenced by gastrointestinal symptoms; thus, treatment with steroids should be promptly initiated. We report the case of a patient who presented with necrosis of the small intestine, which was pathologically diagnosed as polyarteritis nodosa and treated successfully with steroids.An 18-year-old Japanese woman reported a sudden onset of abdominal pain and vomiting that led her to visit our emergency department, where she was evaluated by a physician. On physical examination, tenderness to palpation in the upper umbilical region was noted, and diagnostic imaging with computed tomography showed emphysema of the wall of her small intestine. She was diagnosed as having necrosis of the small intestine requiring urgent surgery. No strangulations were noted intraoperatively but approximately 20 cm of her small intestine was necrotized. The surrounding arteries were examined and no palpable pulse was observed; therefore, segmentectomy of the necrotized regions was performed. Pathological findings revealed active vasculitis with fibrinoid necrosis, as well as destruction, fibrogenesis, and luminal stenosis of the elastic lamina found in the muscular arteries. A diagnosis of polyarteritis nodosa was confirmed as the cause of the necrosis of her small intestine. No recurrence of polyarteritis nodosa symptoms was observed when she was administered 40 mg of prednisolone daily.In cases of idiopathic intestinal necrosis or perforation, systemic diseases such as polyarteritis nodosa should be considered in the differential diagnosis.