Question 32

Question:

A 4-year-old boy presents himself to the emergency room after two days of a steadily worsening right lower quadrant pain and occasionally bloody diarrhea. On careful questioning, the patient’s father thinks that there was another child in his day care center that had a similar condition. Physical exam does not show rebound tenderness but a CT exam shows signs of diffuse lymphadenitis. The patient’s father is nervous because he has ulcerative colitis and is wondering if his son is developing it as well. What is the most likely cause of this patient’s condition?

Correct Answer: E.  Yersinia infection

This patient likely has an infection of Yersinia enterocolitica. It frequently presents with bloody diarrhea and right lower quadrant pain which can mimic Crohn’s disease and appendicitis. Peritoneal signs are not present, which can help distinguish it from appendicitis. In some patients, mesenteric lymphadenitis is present. Furthermore, in some patients with the HLA-B27 serotype, this infection can result in seronegative arthritis.
While both E. coli O157:H7 and shigella infection can result in bloody diarrhea, they would not normally present with diffuse lymphadenopathy.