Trichinosis-related polyarteritis nodosa.

During an outbreak of trichinosis, two young men--one with established trichinosis and the other with suspected infection--were found to have clinical, radiologic and histologic stigmata of a systemic necrotizing vasculopathy equivalent to classic polyarteritis nodosa. The parasitosis manifested as a pentad of fever, myalgias, facial edema, eosinophilia and hyperimmunoglobulinemia E. Features of the arteritis included mononeuritis multiplex, pain in the abdomen and joints, weight loss, hypertension, leukocytosis, thrombocytosis, microhematuria and raised alkaline phosphatase levels. A sustained remission was achieved by the administration of thiabendazole, prednisone and cyclophosphamide. Pathogenetic links between the two diseases are presented: (1) deposition of circulating immune complexes in the vessel wall; (2) adjuvant activity with cross reaction between parasitic antigen and human vessel wall; (3) immunoglobulin E (IgE) aggregates and soluble antigen IgE complexes precipitation in vessel wall; and (4) hypereosinophilia-induced tissue damage. A causal relationship of trichinosis to polyarteritis nodosa is persuasive, and we suggest that cases of hepatitis B surface antigen (HBsAg) negative polyarteritis nodosa, especially those in which myalgias and eosinophilia are prominent, may be related to trichinosis and that, conversely, patients with trichinosis and multiorgan disease should be studied for polyarteritis nodosa.