Background: Yersiniosis due to Yersinia enterocolitica causes pseudoappendicitis syndrome presenting with right lower abdominal pain, fever and leukocytosis. Timely recognition of this entity is important as treatment with antibiotics leads to rapid recovery and can save patient from an unwarranted appendectomy.

Case discussion: A 35-year-old female presented with three day history of right lower quadrant abdominal pain, nausea and vomiting. No fevers or diarrhea were reported. She had food from vendors prior to these symptoms. She was afebrile and physical exam revealed exquisite tenderness upon palpation of the right side of the abdomen, without rebound or rigidity. Laboratory data identified white blood cell count of 12,100/ul and normal amylase, lipase and liver enzymes. Computerized tomography scan of the abdomen discovered marginal proximal appendiceal wall thickening and inflammation of the ascending colon. The overall clinical picture was consistent with acute yersiniosis mimicking appendicitis and hence patient was started on IV ampicillin-sulbactam, pending stool culture and PCR results. At 24 hours, patient reported significant improvement with normalization of leukocyte count. She was discharged on oral ciprofloxacin and metronidazole for a total duration of 7 days. Her stool culture returned negative while the PCR returned positive for Y. enterocolitica, thus confirming the diagnosis.

Conclusion: Current CDC estimates suggest that Yersinia enterocolitica causes almost 640 hospitalizations in the United States every year. Recognizing pseudoappendicitis with history indicative of foodborne illness as a presentation of this uncommon infection is crucial, as treatment with antibiotics leads to prompt recovery.