Central America, Diarrhea, and Eosinophilia: Parasites or Worse?

First Author: Jordan Krieger, B.S. Second Author: Jonathan Lim, M.D. Third Author: Youshi Yin, M.D.

Introduction: A common presentation for gastrointestinal parasitic infection is peripheral eosinophilia. However, inflammatory bowel disease (IBD) can lead to significant and severe complications if left untreated, so physicians should maintain a high index of suspicion of IBD to prevent morbidity and mortality in these patients.

Case Description: A 63-year-old female immigrant from Honduras with no significant past medical history was admitted with one month of watery, non-bloody diarrhea occurring multiple times per hour. Symptoms were not associated with food consumption, sick contacts, or recent travel. She experienced temporary relief with ciprofloxacin and metronidazole, but the symptoms returned after completing antibiotics. Nine years prior to presentation, she had experienced similar symptoms, and colonoscopy revealed recto-sigmoid inflammation and eosinophils in the lamina propria. At that time, she was lost to follow-up.

On admission, her vitals were a temperature of 99.2 Fahrenheit, heart rate 113, blood pressure 139/110, respiratory rate 18, and oxygen saturation of 100% on room air. The physical exam revealed diffuse abdominal tenderness to deep palpation. Her labs were significant for a white blood cell count of 9.3 with 8.4% eosinophils. She had negative Clostridium difficile stool antigen, ova and parasites x3, enteric cultures, and Strongyloides IgG antibodies. Her fecal calprotectin was 207, C-reactive protein was >19, and erythrocyte sedimentation rate was 75. CT imaging of the abdomen was consistent with pancolitis.

Despite empiric ivermectin therapy, the patient's symptoms persisted with intermittent fevers. Colonoscopy showed diffuse inflammation, and biopsies revealed crypt abscesses with neutrophilic infiltration. She was diagnosed with ulcerative colitis and started on daily oral mesalamine. Two months later at her GI clinic follow-up, she reported only one bowel movement per day.

Discussion: For a Central American patient presenting with diarrhea and eosinophilia, an infection with a parasitic organism like Strongyloides, Ascaris, or Trichuris was high on our differential, which also included eosinophilic gastroenteritis, malignancy, and gastrointestinal vasculitis. Keeping a broader differential for peripheral eosinophilia was essential to reaching an accurate diagnosis. The pathogenesis of ulcerative colitis (UC) has been attributed to a dysfunctional reaction of the innate and adaptive immune systems against intestinal bacterial flora. Proliferation of eosinophils in the colon may be a contributing factor due to this increased cellular activation. Antibiotics can have a temporary suppressing effect on mucosal flora that is followed by massive proliferation after cessation of therapy, which may be why our patient experienced transient relief with antibiotics. Key learning points from this case included the clinical presentation and workup for IBD, keeping a broad differential for eosinophilia with diarrhea, and the contribution of eosinophils to the pathogenesis of UC.

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Back to the August 2017 issue of ACP IMpact