Small bowel perforation by Anisakis infection due to raw fish consumption: a rare entity to consider

Anisakidosis is a parasitic infection caused by ingesting the third-stage larvae of the Anisakidae family, a group of nematode parasites found in raw or undercooked aquatic animals including fish. The incidence of this zoonosis is increasing in Western countries, driven by the growing consumption of seafood, especially Japanese cuisine, and influenced by climate change, which is altering the distribution of parasites and the availability of their hosts. Intestinal manifestations are uncommon compared to gastric involvement, and the diagnosis remains difficult. Treatment is conservative in most cases, but some complications will require surgical intervention. We report here un uncommon case of anisakidosis in a young woman who consumed raw fish, complicated by intestinal perforation causing symptoms and radiological images of intestinal obstruction. Diagnostic laparoscopy converted to laparotomy was performed which revealed a covered perforation close to the ileocaecal valve. Small bowel resection and excision of a nodule located close to the perforation were performed. Granulomatous tissue, necrosis in the epiploic nodule with an eosinophilic infiltration and a remnant of an Anisakis larva in its center, were found by pathology. The clinical course was favorable, and no further medication was administrated. Despite this, anisakidosis remains a challenging diagnosis with neither specific laboratory nor radiological findings, and medical history remains a key to guide the diagnosis. The present case is a reminder that, in rare occasions, intestinal anisakidosis may cause serious life-threatening complications requiring surgical intervention for both early definite diagnosis and decision of therapeutic intervention.