Isolated eosinophilic mesenteric vasculitis with extensive thrombosis and splenic infarction in a 13-year-old boy.

There are no generally accepted diagnostic criteria for primary systemic vasculitis, and the application of classification as diagnostic criteria is not feasible and may even be misleading. We report a case of a 13-year-old boy with acute abdomen who was found to have isolated eosinophilic mesenteric vasculitis with extensive thrombosis and splenic infarction. All serological tests were negative, including antineutrophil cytoplasmic antibody. The vasculitis had been successfully controlled with surgical intervention, steroid, and cyclophosphamide therapy. This may be an atypical presentation of Churg-Strauss syndrome.