An Unusual Cause of Perianal Sepsis Due to Ingested Fish Bone: Case Report and Review of the Literature

We present a rare case of a peri-anal abscess caused by an ingested fish bone. A 53-year-old man in good health, without underlying disease presented with progressive and painful peri-anal swelling for 5 days, associated with fever. Physical examination revealed erythema, swelling, and local tenderness on the left side of the anus, with extension to the perineum and opposite side of the anus. Abdominal CT scan showed a gasforming abscess with infiltration into the perineal, perianal, perirectal, perivesical, and prevesical space, with soft-tissue swelling and hyperemic change. The right portion of the bulb/crura/corpus cavernosa and corpus spongiosum of the penis also was involved, compatible with Fournier gangrene. During incision and drainage, a 2.4 cm fish bone was found inside the abscess cavity. The patient recalled having eaten fish around one week prior to this admission. Ingestion of a sharp object can cause perforation of the gastrointestinal tract, not only the upper tract, but even the lower tract and anal canal. A high index of suspicion is needed in cases with a history of foreign body ingestion presenting with ischio-rectal abscess, to aid diagnosis and to prevent progression to Fournier gangrene.