INTRODUCTION: Acute appendicitis due to Enterobius vermicularis is very rare, affecting mostly children. Whether pinworms cause inflammation of the appendix or just appendiceal colic has been a matter of controversy.
CASE PRESENTATION: A Caucasian 52-year-old man was referred to our Emergency Department with acute abdominal pain in his right lower quadrant. The physical and laboratory examination revealed right iliac fossa tenderness and leukocytosis with neutrophilia. An open appendectomy was performed. The pathological examination showed the lumen containing pinworms. Two oral doses of mebendazole were administered postoperatively. The follow-up to date was without incident and he was free of symptoms one year after the operation.
CONCLUSION: The finding of E. vermicularis in appendectomy pathological specimens is infrequent. Parasitic infections rarely cause acute appendicitis, especially in adults.One should keep in mind that the clinical signs of intestinal parasite infection may mimic acute appendicitis, although rare. A careful evaluation of symptoms such as pruritus ani, or eosinophilia on laboratory examination, could prevent unnecessary appendectomies.