Utility of eosinophilia as a diagnostic clue in lower abdominal pain in northern Australia: a retrospective case-control study.

Acute eosinophilic enteritis is a difficult diagnosis to make. Insufficient consideration of eosinophilia may commit patients to surgical treatment when medical therapy may be appropriate. The aim of the study was to determine whether the eosinophil count was considered in the diagnostic evaluation of patients presenting with acute abdominal pain who subsequently underwent appendectomy and whether eosinophilia was related to subsequent histology. The method used in the study was retrospective case-control. None of three patients with increased eosinophil counts had histologically proven appendicitis (Fisher's exact test 0.025); worm segments were seen in two patients. None of 39 patients who had histologically proven appendicitis had increased eosinophil counts. Eosinophilia may be underutilized and helminth infection may not be considered in the differential diagnosis of abdominal pain. A normal eosinophil count in the setting of clinically suspected appendicitis may make the diagnosis of eosinophilic enteritis less likely, but does not exclude it. Patients with abdominal pain and peripheral eosinophilia appear less likely to have acute appendicitis on subsequent histology; however, further study is required to validate these findings. The decision to operate remains one of clinical judgement.