Computed tomographic and endoscopic findings of multiple gastric anisakiasis

A 36-year-old man presented with sudden onset of severe abdominal pain. A CT scan was performed first, which showed marked thickening of the gastric wall. Gastric anisakiasis was suspected because he had eaten sashimi (a raw fish dish), including salmon and tuna, the night before. An upper gastrointestinal endoscopy revealed three Anisakis larvae invading the gastric wall. All larvae were removed by the biopsy forceps. His symptoms were resolved after the removal. Anisakiasis is a gastrointestinal parasitic infection of humans caused by ingestion of raw or undercooked seafood containing Anisakis larvae, resulting in severe gastrointestinal disorders and allergic reactions. Salmon, herring, cod, mackerel, squid, and flounder are known intermediate hosts. Cases of anisakidosis are increasing globally. Although gastric anisakiasis is a relatively common disease in Japan, it is unusual to find marked thickening of the gastric wall on CT scans and multiple anisakiasis on upper endoscopy, as shown in this case. Our case highlights the importance of a careful history leading to prompt diagnosis and treatment of gastric anisakiasis in cases presenting with acute onset of severe abdominal pain several hours after ingestion of raw or undercooked seafood. Healthcare professionals and edible seafood handlers should increase their awareness of fish parasites. Proper freezing or cooking of seafood is an important prophylactic measure.