Intestinal anisakiasis as a rare cause of small bowel obstruction

Anisakiasis presenting to the ED: clinical manifestations, time course, hematologic tests, computed tomographic findings, and treatment

“…Direct tissue damage due to the invasion of Anisakis larvae involves the development of eosinophilic granulomas or perforations. A pathologic examination of the resected small intestine from a patient with small intestinal anisakiaisis who underwent surgery for a suspected acute abdomen showed transmural edema, congestion, and diffuse infiltration of neutrophils and eosinophils [2,13]. Because a gastric or intestinal endoscopic biopsy is not painful, the pain of anisakiasis may be caused by an allergic reaction rather than by direct tissue damage.…”

“…Previous reports have revealed that the radiologic features of gastric and intestinal anisakiasis included the following findings: the presence of submucosal edema of the stomach and intestine (edematous wall thickening), fat infiltration of the mesentery around the involved stomach and intestine, dilatation, fluid collection in the involved stomach and intestine, abdominal lymphadenopathy, and the presence of ascites [2,[10][11][12].…”

“…The larvae can penetrate the gastrointestinal tract and cause gastric or small intestinal anisakiasis. Every year, approximately 20 000 cases of anisakiasis are reported worldwide, with more than 90% from Japan and most of the other cases from Spain, the Netherlands, and Germany, depending on the habits of fish consumption; however, anisakiasis remains a rare disease [1][2][3]. Although the prevalence of anisakiasis is rare in the United States and European Union, particularly in inland areas, compared with that in Japan [2,3], the incidence is expected to increase, given the growing popularity of Japanese cuisine, such as sushi or sashimi.…”

“…Although the clinical symptom of anisakiasis is abdominal pain, this clinical finding is nonspecific, and the patient may be misdiagnosed or may unnecessarily undergo surgery for different ailments, including appendicitis, ileus, and peritonitis [2,4,5]. In the emergency department (ED), we examine several patients with acute abdominal pain; therefore, we should consider anisakiasis when the cause of abdominal pain cannot be determined by initial assessment [2,6,7].…”

“…In the emergency department (ED), we examine several patients with acute abdominal pain; therefore, we should consider anisakiasis when the cause of abdominal pain cannot be determined by initial assessment [2,6,7]. However, few case reports have described the precise clinical manifestations, time course, hematologic test results, and computed tomographic (CT) findings of patients with anisakiasis; and this information would aid in the early and definitive diagnosis of anisakiasis in emergency settings.…”