Case Presentation: A 43- year- old healthy man presented to the emergency department with chills, arm pain, swelling, and redness after sustaining a puncture wound from a dead catfish. Vital signs included temperature 38.2 C, HR 116, BP 87/55. He had left medial wrist and forearm erythema, swelling and induration surrounding a small puncture wound as well as decreased wrist range of motion. Lab work was notable for WBC 14.1 with 2% bands. Due to a penicillin allergy he was started on broad- spectrum antibiotics with vancomycin, ciprofloxacin, and doxycycline. Within several hours there was marked lymphangitic spread and Clindamycin was added. CT scan of the arm showed no retained foreign body or deep fascia infection. Initial blood culture was positive for Plesiomonas shigelloides. Ultimately, given clinical improvement and repeat negative blood cultures, he was discharged on oral Ciprofloxacin to complete a 14- day course.

Discussion: Health care providers frequently encounter cellulitis, which accounts for over 537,000 hospitalizations and $3.74 billion in healthcare costs yearly. It is critical to obtain a thorough history in order to identify potential complications and effectively manage care. In this case, the mechanism of injury significantly altered the antibiotic selection. Catfish are the number one cause of a fish-related injury in the USA. Freshwater catfish have dorsal and pectoral barbs containing venomous glands. When threatened, the barb can penetrate and release venom leading to local inflammation, erythema, and tissue necrosis. Envenomation may result in systemic symptoms including tachycardia, hypotension, nausea, emesis, and dizziness. Many organisms are found on catfish but rarely Plesiomonas shigelloides, a facultatively anaerobic, oxidase-positive, gram-negative rod. When ingested via contaminated water or raw food, Plesiomonas typically leads to gastrointestinal symptoms. There are few case reports of Plesiomonas bacteremia. These are typically seen in immunocompromised hosts and thought to be due to bacterial translocation across the bowel wall.

Conclusions: Due to the mechanism of injury, antibiotic coverage for our patient’s cellulitis had to include gram-negative bacteria found in freshwater as well as gram-positive bacteria. Evaluation for retained foreign body and prompt removal is necessary. Complications of catfish envenomation include pain, tissue necrosis, and limb amputation. The unusual mechanism of injury also led to bacteremia with an organism that is usually only found in the gastrointestinal tract and has led to illness in immunocompromised hosts. This presentation of cellulitis from an unusual cause demonstrates the importance of a thorough history in making an effective management plan. As in this case, the typical antibiotic coverage for cellulitis was not sufficient and required the addition of gram-negative coverage.