Gastrointestinal involvement in polyarteritis nodosa carries a poor prognosis. A 1982 review from our institution reported acute abdominal syndromes in 31% of patients with polyarteritis nodosa, and that all 5 patients with acute surgical abdomens died. We reviewed our more recent experience to determine if outcomes have changed since.

We reviewed the records of all patients with polyarteritis nodosa in our vasculitis database between 1986 and 2000. Inclusion criteria were a diagnosis of polyarteritis nodosa, symptoms or signs of gastrointestinal involvement, and either a mesenteric angiogram consistent with polyarteritis nodosa or histopathologic proof of a medium-vessel vasculitis. We calculated a prognostic (5 factor) score for all patients.

We identified 24 patients with polyarteritis nodosa who had gastrointestinal involvement during their illness. Thirteen (54%) of the patients developed acute surgical abdomens, 3 of whom died (P = 0.02 by comparison with the historical cohort). Mean (± SD) prognostic scores were higher among patients in the acute abdomen group compared with those who did not have acute abdominal syndromes (1.7 ± 0.9 vs. 0.6 ± 0.7, P = 0.002), corresponding with the observed mortality in these groups.

Gastrointestinal involvement occurs commonly in polyarteritis nodosa and carries a poor prognosis. Compared with a historical cohort at our institution, mortality from this complication may have decreased, perhaps because of earlier diagnosis.