Pseudoappendicitis

Excerpt

Pseudoappendicitis describes any condition that mimics acute appendicitis. The characteristic signs and symptoms of acute appendicitis are acute right lower quadrant abdominal pain, anorexia, and point tenderness of the right lower abdominal quadrant.

Typically, pseudoappendicitis syndrome is due to acute yersiniosis, a zoonotic disease caused by Yersinia enterocolitica. Y enterocolitica is a gram-negative coccobacillus of the family Enterobacteriaceae. However, in rare cases, pseudoappendicitis may be due to Campylobacter infection.

Acute yersiniosis and Campylobacter infection can present with symptoms such as right lower quadrant abdominal pain, fever, vomiting, leukocytosis, and mild diarrhea, thus mimicking the typical signs of appendicitis. More severe cases may present with mesenteric adenitis or terminal ileitis. However, most cases of acute yersiniosis are mild and self-limiting.

Immunocompromised patients are more susceptible to infections from Y enterocolitica and prone to developing more severe sequelae of the disease, including sepsis and splenic or hepatic abscesses from bacterial dissemination. Individuals with hereditary hemochromatosis are also prone to Y enterocolitica infections. The higher-than-normal total body iron of patients with hereditary hemochromatosis proves a hospitable environment for the siderophilic Y enterocolitica.

Y enterocolitica is the most common bacterial contaminant in packed red blood cells. While most patients with acute yersiniosis will experience mild and self-limited disease, older persons and those with underlying comorbidities are at increased risk of infection and severe symptomatology. Patients who have recently received a blood transfusion and subsequently develop symptoms inconsistent with transfusion reactions, such as generalized malaise, gastrointestinal symptoms, and abdominal pain, should be evaluated for Y enterocolitica bacteremia.