We have found mucosal eosinophilia in 71% of children undergoing endoscopy with mucosal biopsy for dyspepsia. However, eosinophil density does not necessarily correlate with eosinophil activation and many eosinophil-derived mediators are bioactive in a concentration-dependent fashion. (3) In previous investigations, we have found evidence of moderate to extensive eosinophil degranulation in the biopsies of dyspeptic children who had normal mucosal eosinophil densities. (4)