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Presenting features of Enterobius vermicularis in the vermiform appendix.
Mikael H Sodergren1, Paras Jethwa, Simon Wilkinson
1Department of Surgery, Queen Mary's Hospital, Sidcup, Kent, UK. m.sodergren@imperial.ac.uk
Scandinavian Journal of Gastroenterology
|December 17, 2008
Summary
Pinworm (Enterobius vermicularis) infestation in the appendix can mimic appendicitis but often presents with lower white cell counts and Alvarado scores. Consider pinworms in patients with recurrent right iliac fossa pain and atypical appendicitis markers.
Area of Science:
- Gastroenterology
- Parasitology
- Surgical Pathology
Background:
- Enterobius vermicularis (pinworm) infestation can mimic acute appendicitis symptoms.
- Evidence suggests pinworms do not always cause acute appendicitis.
Purpose of the Study:
- To characterize clinical presentation of pinworm infestation in the vermiform appendix.
- To identify features suggestive of appendiceal pinworm infestation.
Main Methods:
- Retrospective analysis of patients undergoing appendicectomy with appendicular pinworms (1998-2003).
- Comparison with 54 controls with confirmed acute suppurative appendicitis.
- Analysis of presenting features, vital signs, and modified Alvarado scores.
Main Results:
- 1.5% (18/1150) of appendicectomies revealed pinworms; only 2/18 showed inflammation.
- Patients with pinworms had lower white cell counts (WCCs) and Alvarado scores than controls.
- Recurrent right iliac fossa (RIF) pain and prior admissions were more common in pinworm cases (p<0.001).
Conclusions:
- Appendiceal pinworm infestation should be considered in differential diagnosis for recurrent RIF pain without elevated WCCs or high Alvarado scores.
- Early fecal sampling, cellophane tape tests, and empirical antiparasitic treatment may benefit these patients.
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