Sudden-Onset Severe Back Pain Caused by Acute Gastric Anisakiasis.

Anisakiasis is a parasitic disease that usually causes acute abdominal pain, nausea, and vomiting after the ingestion of raw seafood. We present a case of anisakiasis in an 80-year-old man who complained of sudden-onset severe back pain that was reminiscent of aortic dissection. This case shows that anisakiasis should be considered as a possible differential diagnosis in patients with not only abdominal pain but also back pain. In addition, for "diagnostic excellence," it is essential to return to a comprehensive medical history that allows the reassessment of the diagnosis even when it differs from the initial differential diagnosis.