Small bowel anisakiasis with self-limiting clinical course.

A 54-year-old man complained of lower abdominal pain and diarrhea. Laboratory examinations revealed an elevated serum level of C-reactive protein (4.45 mg/dL) and an increased percentage of eosinophils (7.1%, normal; 3-5 %) whereas white blood cell count was normal. He had ingested raw fish one day before the onset of disease. Abdominal computed tomography (CT) showed wall-thickening of the ileum and accumulation of ascites (Picture 1A, B). He was diagnosed as small bowel anisakiasis due to marked elevations of serum total IgE (1,600 U/mL, normal<138) and Anisakis-specific IgE (>100 UA/mL, normal<0.7). His symptoms were self-limiting and the percentage of eosinophils was decreased (2.4%). Abnormal CT findings disappeared one week later (Picture 1C, D). Different from gastric anisakiasis, direct demonstration of Anisakis is difficult in most cases of enteric anisakiasis (1). Accumulation of ascites and bowel wall thickening are typical CT findings in enteric anisakiasis (2). Abdominal CT in combination with detection of serum Anisakis-specific IgE is useful for the diagnosis of enteric anisakiasis.